Version 1: Log book reports up to 17 December 2018
Executive Summary
Since publishing our original post on these faults, Flip the Fleet has now received 22 reports of problems with Nissan Leaf brakes, all but one of which occurred in New Zealand. We estimate that 9 of these resulted from a firmware fault in the Electrically-driven Intelligent Brake Control Unit (EDIB) which causes the braking system to become unresponsive. There appear to be two states following the EDIB fault: one where impaired, but still relatively effective braking can be achieved with the engagement of the Leaf’s Anti-lock Braking System (ABS); and a second state where the ABS does not engage and the driver alone arrests the car by applying intense pressure on the brake pedal and stopping power is much reduced. The same car can exhibit both states of the EDIB fault but the relative frequency and conditions that trigger the alternate states are unknown. The New Zealand Transport Agency (NZTA) has conducted a single test of a Leaf on a roller brake machine in the EDIB fault mode (which appears to have been in the first state) and concluded that it meets the WoF requirements. This is very encouraging, but we believe that further testing is required to fully evaluate the consequences of brake issues and especially to explore the existence of the second severely impairing braking state that appears to be associated with the ABS not being engaged to help arrest the vehicle.
If the observed probability of EDIB fault per car does not change, and if the 2013-2016 fleet size continues to double annually, we can expect about 11 such faults over the coming year. This observed incidence rate is probably underestimated and the sample size is small, so the statistical uncertainty band for this prediction ranges from 6 to 21 faults in the next year.
In addition to the 9 cases with the EDIB faults, another 13 cases of a diverse range of braking issues have also been reported that do not appear to relate to the primary EDIB fault that is being observed. They range from relatively minor to serious events. Many may be solved by recalibration of the existing brake firmware or potentially other forms of maintenance.
The descriptions of the events leave no doubt of the distress of the affected drivers and potential risk and expense involved:
- one returned the vehicle to the dealer and bought an internal combustion vehicle instead;
- one is urging that no more Leafs are sold until the problem he experienced is fixed;
- one nearly rear-end a truck but was able to veer left into an empty lane and turn left again because the traffic light happened to go green at the same moment;
- one nearly hit a rapid charging station because the fault occurred as they were pulling in to recharge;
- one ended up in the middle of an intersection and is now too frightened to drive the car;
- one would have incurred over $1,500 in vehicle recovery costs had they not had AA Roadside Recovery policy, and potentially several thousands of dollars in replacing the full brake module.
Until future monitoring and more extensive research is conducted to better assess and manage any risk, Nissan drivers can best help protect themselves and others by becoming fully aware of the potential for brake faults and what to do if it happens to them. Based on our research and testing, we believe that in most EDIB fault situations, slamming the brake pedal right to the floor and exerting as much force as you can muster will be the most effective way to stop the vehicle. Ignore any loud graunching sounds and juddering of the car – they are a normal part of the brake assist mode. Unfortunately, during normal EDIB behaviour many Leafs tend to have quite touchy brakes where gentle and variable brake application may be required, so many Leaf owners may be subconsciously conditioned to never firmly apply the brakes.
Recurring faults sometimes happen in the same car, even in quite quick succession, so it is imperative that you stop and seek help immediately after the first occasion. Regular servicing and maintaining a healthy 12V battery may also help reduce the likelihood of a fault, especially of minor types. Never drive the car if brake warning lights appear at start-up.
If a fault happens to you, please use LeafSpy Pro to read the DTCs and ECU versions, accessible via the Service Menu and send them to Flip the Fleet along with a log book report. Then take your car to a service agent, preferably a certified Nissan dealer that is experienced in fixing and servicing Leafs so they can inspect the ECU and DTC information and report to Nissan New Zealand. It is best practice to record then clear all historical DTC notifications so that you can track the recent performance of your car.
Insufficient information is presented here for a fully informed scientific judgement of whether sufficient risk exists for NZTA and Nissan to intervene and remedy the faults; nor can the available information reliably rule out if intervention is needed. Flip the Fleet is not mandated or equipped to make an overall risk assessment – that is a job for NZTA alone. Nissan have not acknowledged the existence of these apparent faults, nor indicated whether the brake firmware ‘C’ updates seen in some overseas cars will fix the braking problems described in this study.
We urge the NZTA to urgently complete a formal risk assessment and advise answers to three fundamental and interlinked questions:
- Are the 2013-2016 Leafs safe to drive?
- Are firmware remedies available to fix the problems observed here?
- If a remedy exist, will it be made available at an affordable price for drivers of Leafs imported second-hand to New Zealand?
Introduction
This is an update to our original post entitled Reported failures of the e-ACT Electrically-driven Intelligent Brake Control Unit in Nissan Leafs manufactured between November 2012 and February 2016 which was posted on Flip the Fleet’s website on November 23, 2018 (click here to view). Flip the Fleet is a ‘citizen science’ coalition of electric vehicle (EV) owners from throughout New Zealand that is creating a communal database on all manner of performance indicators for EVs in New Zealand conditions.
We were aware of five reported cases of one type of brake fault when we posted that original report. Since then we set up an online form for Leaf owners to report any braking issues at www.flipthefleet.org/leaf-brakes-logbook (hereafter referred to as the “brakes logbook”). We subsequently received 16 new reports of braking aberrations in Nissan Leafs from New Zealand and an additional case from Denmark.
This report provides an interim summary of the information received to date to help Leaf owners, dealers and decision-makers form a response. It is intended as a “living document” because we will update the case histories as more logbook reports are received, with subsequent analysis and recommendations as better information comes to hand.
This report starts with a summary of the case histories received so far. We then describe different categories of unexpected brake behaviour and their symptoms. These observed cases are next analysed together with results of some road tests of simulated EDIB faults to narrow down potential causes and their implications. We end by listing recommendations about what drivers and owners can do to help minimise risks of future brake faults. Our questions to and responses from Nissan New Zealand, the Motor Industry Association and NZTA are also recorded in full appendices to highlight the political and economic challenges in securing a remedy to the braking faults.
Methods
An online report was posted at https://flipthefleet.org/2018/leaf-brakes-failures/ on 23 November 2018. The potential risk and preliminary descriptions of the original five cases were described in that report and around 1,200 participants in Flip the Fleet received an alert about the issue and invitation to fill in the brakes logbook at that same time. There was considerable media coverage in New Zealand in the ensuing week, so the request to fill in the logbook reached many other Leaf owners who were not part of Flip the Fleet. The drivers of all five of the original brake fault cases have all now submitted a logbook report in order to standardise the information as best as possible. Respondents were asked to describe the incident and report warning symbols on their dashboards, approximate temperature, their subsequent reporting and fixes of the problem and whether they had 12V battery problems or 12V battery replacements just before or after the incident(s). Records of brake firmware identifiers and Diagnostic Trouble Codes (DTCs) were recorded (usually by LeafSpy Pro app) if available. The current version (v1) of this report includes all logbook reports of brake faults up until 12 December 2018.
Recent posts on New Zealand EV Facebook group forums and emails to brakes@flipthefleet.org have also described braking concerns or events for Leafs for which we have not yet received a formal logbook report. An additional report of braking problems in a Mitsubishi Outlander was also received which has not been considered further in this analysis.
We conducted a small number of road tests of simulated faults on the 10th and 24th of November. In the first set of tests, the stopping distance of a 2014 Leaf was measured by two drivers who each hit the brakes as hard as they could at the point they passed a road cone placed alongside a deserted straight and sealed road in dry conditions. Stopping distance was measured in trials at 30, 50 and 100 km/h. The EDIB fault was then triggered experimentally by sending a command over the CAN Bus and the trials repeated. On 24th November, two of the original five drivers who had experienced real EDIB were asked to test emergency braking in another 2014 Leaf that had the same experimentally triggered fault. A third driver (one of our authors of this report) also tested the fault mode at a variety of speeds. A home built pressure sensor was used to approximately measure pressure applied to the brake pedal. The aim of the 24 November trials was to establish whether our experimental intervention created a qualitatively similar experience (e.g. “feel” of the brake pedal and noises) as those experienced when the actual fault occurred. More details of the methods and results are provided in Appendix 5. Our simulations were not intended to be full scientific tests or measures of the increased stopping distance – rather they were conducted to assess the broad nature of the EDIB fault, and provide a preliminary estimate of the scale of any impairment of braking.
A search of overseas social media forums and websites revealed several instances of brake faults which we reported in a general way in our original report. The reports are referenced in Appendix 4.
Originally we used the term “brake failure” in a generic sense to capture all manner of unexpected and reduced braking performance issue. This perhaps caused some unintended alarm, so we now use the term brake fault. Unless specified, at no time does our use of the term fault mean catastrophic failure of brakes where there is no resistance to arresting the car. For consistency with the NZTA reports we will use the term Electrically-driven Intelligent Brake (EDIB) in this report (see Appendix 1 for clarification).
The term MY for Model Year is used in the car industry. This report focuses on MY2013 to MY2016 which are all MY2013 to MY2015 cars and some MY2016 cars manufactured from November 2012 to February 2016. The MY provides a guide for when changes were made to the EDIB version. A MY2014 car manufactured in late 2013 may be called a 2013 car in New Zealand, but have the EDIB for a MY2014 car.
Results
Reported case histories
Details of the cases reported in the logbook can either be downloaded by clicking the excel button or inspected by clicking on each case number below.
Download as Excel
The first case studies listed here have been identified as probable EDIB faults:
First occasion the brakes failed while stopped on a downhill slope. About a month later they failed when slowing down from 50kmh.
Country
New Zealand
Model year
2014
Month of manufacture
[no answer provided]
The 5-digit “brake firmware” code as displayed via the “ECU versions” service screen on LeafSpy at the time of failure
[no answer provided]
“Brake” codes that you can see on the “DTCs” service screen on LeafSpy
ABS Module – U1000 & U110D, VCM – U1000 & P3195
Has your Leaf experienced a brake system failure/s?
Yes, a few! (please provide details below)
What was the outside temperature when your failure/s occured?
Moderate
Shortly before or after the failure/s, did you find out that your 12V battery was very degraded?
Neither
Shortly before or after the failure/s, did you disconnect the 12V battery?
Neither
Do you recall seeing any warning lights before the failure/s?
Yes (if you remember, please tell us which light/s as a comment)
Do you recall seeing any warning lights during and/or after the failure/s?
Yes (if you remember, please tell us which light/s as a comment)
How fast were you driving at the time of the failure/s?
50kph
When the failure/s occurred, did you hear strange noises from under the bonnet?
I don’t remember
How did you come to a stop?
Changed into park
As you were stopping, was there a juddering halt, or a smooth one?
Juddering halt
Was anyone injured?
No
Was any vehicle/property damaged?
No
Did you report the failure/s to a Nissan-authorised service centre or dealer (hereafter, just “Nissan”)?
No
Was the failure reported to an authority/ies other than Nissan? If so, who?
To the dealer I bought the car from
What did Nissan do by way of remedy?
[no answer provided]
Was there a cost for this remedy?
[no answer provided]
Has your e-ACT Electrically-driven Intelligent Brake Control Unit been replaced completely?
[no answer provided]
Is there anything we missed?
Lost faith in Nissan Leafs and would not own one again
Flip The Fleet’s own classification of this case
EDIB Fault
We experienced a sudden brake failure with our Leaf when approaching traffic lights and very narrowly missed colliding into the rear of a fuel tanker. The only way I could finally stop the vehicle was to activate the park brake. Although we estimated we were traveling about 8 Km/h at the time, but since simulating a similar situation we now believe we may have been traveling about 12 km/h or more at the time I first became aware that the brakes had failed. I suspect the park brake would be safe to use or even be effective at high speed.
At the time, I believed I had pushed as hard as possible on the brake pedal when first realising the brakes had failed. I then concentrated on taking avoidable action by changing to the inside/left turning lane until we were traveling slow enough to apply the park brake. Once in the left turning lane we were lucky because there was no real danger from other traffic, hence I was then able to delay applying the park brake until we had slowed to a very slow speed.
At the time when I realised the brakes had failed I was then applying continuing excess pressure to the brake pedal and was aware there was a grouching sound I thought was coming from the wheel/brakes and felt a jerky feel on the brake pedal. In the very short period this was happening I thought we were experiencing a mechanical fault such as the brake pads had come adrift and there was a metal to metal contact being experienced in the wheel brake area. Because of this effect happening at the time, it may have caused me to release the pedal pressure and concentrate in looking for a way out by looking out for traffic before changing lanes etc. My real concern was we were going to crash into the tanker in front and I needed to take immediate and even drastic action.
At no time was I aware there was any braking action taking place whatsoever, even though I was exerting considerable and increasing pressure on the brake pedal. But my time doing this may have been short because my main concern quickly became apparent I needed to avoid an accident, lookout for traffic and change lanes as soon as possible where we could safely slow down and apply the park brake.
As far as I was aware, there were no visual or audio warnings but everything happened very quickly. Traffic had quickly built up from behind and we needed to turn the electrics off and restart the vehicle again and get around the corner away from the traffic. After turning the power off and restarting again, everything was back to normal again.
Country
New Zealand
Model year
2015
Month of manufacture
[no answer provided]
The 5-digit “brake firmware” code as displayed via the “ECU versions” service screen on LeafSpy at the time of failure
[no answer provided]
“Brake” codes that you can see on the “DTCs” service screen on LeafSpy
ABS Module – U1000 & U110D, VCM – U1000 & P3195
Has your Leaf experienced a brake system failure/s?
Yes, just one. (please provide details below)
What was the outside temperature when your failure/s occured?
Moderate
Shortly before or after the failure/s, did you find out that your 12V battery was very degraded?
Neither
Shortly before or after the failure/s, did you disconnect the 12V battery?
Neither
Do you recall seeing any warning lights before the failure/s?
No
Do you recall seeing any warning lights during and/or after the failure/s?
No
How fast were you driving at the time of the failure/s?
believed about 8kph but since believe about 12 kph or more
When the failure/s occurred, did you hear strange noises from under the bonnet?
[no answer provided]
How did you come to a stop?
activated park brake when traveling very slow
As you were stopping, was there a juddering halt, or a smooth one?
[no answer provided]
Was anyone injured?
No
Was any vehicle/property damaged?
No
Did you report the failure/s to a Nissan-authorised service centre or dealer (hereafter, just “Nissan”)?
Yes
Was the failure reported to an authority/ies other than Nissan? If so, who?
Yes NZTA
What did Nissan do by way of remedy?
NZTA and Nissan have done Nothing!
Was there a cost for this remedy?
[no answer provided]
Has your e-ACT Electrically-driven Intelligent Brake Control Unit been replaced completely?
[no answer provided]
Is there anything we missed?
[no answer provided]
Flip The Fleet’s own classification of this case
EDIB Fault
Parked the car in a carpark, when I started the car, the Red and Yellow warning lights were on. The traction control warning light was on. The brake warning light was on. Car would drive, pressing down brake pedal with regular pressure resulted in no braking. Pressing down hard resulting in juddering ABS-like braking.
If stationary and pressing hard on brake, would hear a ticking/whirring sound from under the car/hood.
Replacement of the braking control unit fixed the issue.
Country
New Zealand
Model year
2012
Month of manufacture
11
The 5-digit “brake firmware” code as displayed via the “ECU versions” service screen on LeafSpy at the time of failure
[no answer provided]
“Brake” codes that you can see on the “DTCs” service screen on LeafSpy
[no answer provided]
Has your Leaf experienced a brake system failure/s?
Yes, just one. (please provide details below)
What was the outside temperature when your failure/s occured?
Moderate
Shortly before or after the failure/s, did you find out that your 12V battery was very degraded?
Neither
Shortly before or after the failure/s, did you disconnect the 12V battery?
Yes, after
Do you recall seeing any warning lights before the failure/s?
No
Do you recall seeing any warning lights during and/or after the failure/s?
Yes (if you remember, please tell us which light/s as a comment)
How fast were you driving at the time of the failure/s?
0
When the failure/s occurred, did you hear strange noises from under the bonnet?
Yes
How did you come to a stop?
N/A
As you were stopping, was there a juddering halt, or a smooth one?
Juddering halt
Was anyone injured?
No
Was any vehicle/property damaged?
No
Did you report the failure/s to a Nissan-authorised service centre or dealer (hereafter, just “Nissan”)?
No
Was the failure reported to an authority/ies other than Nissan? If so, who?
Car dealership, fixed under warranty
What did Nissan do by way of remedy?
[no answer provided]
Was there a cost for this remedy?
[no answer provided]
Has your e-ACT Electrically-driven Intelligent Brake Control Unit been replaced completely?
Yes
Is there anything we missed?
[no answer provided]
Flip The Fleet’s own classification of this case
EDIB Fault
The first three or four instances I didn’t register as brake failure. When applying the brakes there was little pedal with no real braking power. This was quickly followed by the brakes suddenly grabbing. All a bit worrying when you have no idea when its going to happen. There seemed to be weeks or months between each incident. The last time this happened we nearly ran into a charging station. Some two hours later we were leaving a different charging station and found we had no brakes at all. I had to apply extreme pressure to the brake pedal but this gave me very little stopping power, not to mention the terrible noise it made, plus there was a sort of vibration in the brake pedal. Limped to the nearest garage (thankfully only 100 meters away) using mostly the park brake. Vehicle not was driveable.
Country
New Zealanmd
Model year
2014
Month of manufacture
January
The 5-digit “brake firmware” code as displayed via the “ECU versions” service screen on LeafSpy at the time of failure
3NG9B
“Brake” codes that you can see on the “DTCs” service screen on LeafSpy
C1A88 0108 BRAKE
Has your Leaf experienced a brake system failure/s?
Yes, a few! (please provide details below)
What was the outside temperature when your failure/s occured?
Moderate
Shortly before or after the failure/s, did you find out that your 12V battery was very degraded?
Yes, after
Shortly before or after the failure/s, did you disconnect the 12V battery?
Neither
Do you recall seeing any warning lights before the failure/s?
No
Do you recall seeing any warning lights during and/or after the failure/s?
Yes (if you remember, please tell us which light/s as a comment)
How fast were you driving at the time of the failure/s?
10/20 kph
When the failure/s occurred, did you hear strange noises from under the bonnet?
Yes
How did you come to a stop?
Extreme pressure on brake pedal.
As you were stopping, was there a juddering halt, or a smooth one?
I don’t remember
Was anyone injured?
No
Was any vehicle/property damaged?
No
Did you report the failure/s to a Nissan-authorised service centre or dealer (hereafter, just “Nissan”)?
No
Was the failure reported to an authority/ies other than Nissan? If so, who?
No
What did Nissan do by way of remedy?
[no answer provided]
Was there a cost for this remedy?
[no answer provided]
Has your e-ACT Electrically-driven Intelligent Brake Control Unit been replaced completely?
No
Is there anything we missed?
In the four or so cases when the brakes had a little blip I do not recall any warnings lights appearing. After the complete brake failure there were several warning lights displayed – A yellow exclamation,
Flip The Fleet’s own classification of this case
EDIB Fault
After restarting my LEAF and whilst reversing out of a car park space the brakes felt very strange. Brake travel went to the floor, there was no assisted braking and you could feel and hear the brakes grinding against the discs. It was difficult to stop the vehicle.
On putting the car in Drive the car drove normally, but there was no improvement in braking. It was extremely difficult to stop the vehicle – even from a very slow speed. Accompanied by a grinding noise. So I stopped the car and called the [roadside service company redacted].
Both red and yellow warning symbols were lit plus the yellow brake/traction symbol.
The [roadside service company redacted] engineer had absolutely no idea what was wrong. I suggested we disconnect the 12V battery for 5 minutes. This ‘reset’ did the trick and everything returned to normal. No problem since.
Interesting I subsequently found out that one of my children accidentally triggered the alarm/immobiliser immediately prior to me returning to my LEAF. So I am thinking this may have somehow triggered the glitch.
I was fortunate that I noticed the issue in a car park. If I had driven straight on to an open road and not had to brake until travelling at speed – this situation would have been very dangerous and frightening.
Country
New Zealand
Model year
2014
Month of manufacture
February
The 5-digit “brake firmware” code as displayed via the “ECU versions” service screen on LeafSpy at the time of failure
3NG5A
“Brake” codes that you can see on the “DTCs” service screen on LeafSpy
C118A 0108 ABS E-Driven Int Brake System BRC-124, U110D ABS E-Driven Intelligent Brake Comm BRC-130
Has your Leaf experienced a brake system failure/s?
Yes, just one. (please provide details below)
What was the outside temperature when your failure/s occured?
Moderate
Shortly before or after the failure/s, did you find out that your 12V battery was very degraded?
Neither
Shortly before or after the failure/s, did you disconnect the 12V battery?
Yes, after
Do you recall seeing any warning lights before the failure/s?
No
Do you recall seeing any warning lights during and/or after the failure/s?
Yes (if you remember, please tell us which light/s as a comment)
How fast were you driving at the time of the failure/s?
5kph
When the failure/s occurred, did you hear strange noises from under the bonnet?
Yes
How did you come to a stop?
Hard “manual” braking.
As you were stopping, was there a juddering halt, or a smooth one?
Juddering halt
Was anyone injured?
No
Was any vehicle/property damaged?
No
Did you report the failure/s to a Nissan-authorised service centre or dealer (hereafter, just “Nissan”)?
No
Was the failure reported to an authority/ies other than Nissan? If so, who?
No
What did Nissan do by way of remedy?
NA (Disconnection/reconnection of 12V battery fixed the issue).
Was there a cost for this remedy?
No
Has your e-ACT Electrically-driven Intelligent Brake Control Unit been replaced completely?
No
Is there anything we missed?
Warning lights during failure: Red triangle, yellow triangle & yellow traction/brake warning light.
It is great that FTF is being proactive in this regard. But please avoid creating a panic with the general public. Getting Nissan to provide the firmware support should be the focus.
Flip The Fleet’s own classification of this case
EDIB Fault
During cold conditions (about 2 degrees C) and after a 30 minute stop, drove off at modest speed (20-30 km/h) and suffered what appeared to be a complete loss of brakes. A loud noise was heard from two places under the bonnet. No warning lights were noticed at start-up. To bring the car to a halt it was turned off. The car was scanned by automotive engineers when back in Dunedin and it was found that the fault had caused the Brake Control Unit to become invisible on the CAN Bus (i.e., it was non-functional). Disconnecting and reconnecting the 12V battery several days later finally caused to Brake Control Unit to function again. The 12 volt battery had been replaced 3 weeks before and appeared to be holding its charge well.
Country
New Zealand
Model year
2015 24 kWh S
Month of manufacture
June 2015
The 5-digit “brake firmware” code as displayed via the “ECU versions” service screen on LeafSpy at the time of failure
Was ‘A’ series at time of failure (FW#: 3NG9A); Replaced with B version by Walter Larason 23 September; and then C on 24 November.
“Brake” codes that you can see on the “DTCs” service screen on LeafSpy
ABS U1000 & U110D VCM U1000 & P3195 BCM U1000 + some possibly historic fault codes Airbag U1000
Has your Leaf experienced a brake system failure/s?
Yes, just one. (please provide details below)
What was the outside temperature when your failure/s occured?
Very cold
Shortly before or after the failure/s, did you find out that your 12V battery was very degraded?
Yes, before
Shortly before or after the failure/s, did you disconnect the 12V battery?
Yes, both before and after
Do you recall seeing any warning lights before the failure/s?
No
Do you recall seeing any warning lights during and/or after the failure/s?
Yes (if you remember, please tell us which light/s as a comment)
How fast were you driving at the time of the failure/s?
20 – 30 kph
When the failure/s occurred, did you hear strange noises from under the bonnet?
Yes
How did you come to a stop?
Switched the car off
As you were stopping, was there a juddering halt, or a smooth one?
Juddering halt
Was anyone injured?
No
Was any vehicle/property damaged?
No
Did you report the failure/s to a Nissan-authorised service centre or dealer (hereafter, just “Nissan”)?
No
Was the failure reported to an authority/ies other than Nissan? If so, who?
Yes, to VIA
What did Nissan do by way of remedy?
[no answer provided]
Was there a cost for this remedy?
[no answer provided]
Has your e-ACT Electrically-driven Intelligent Brake Control Unit been replaced completely?
No
Is there anything we missed?
[no answer provided]
Flip The Fleet’s own classification of this case
EDIB Fault
New Zealand 2016 X 24kw
From parked brakes did not work. Heavy pressing worked accompanied by gear grinding noises. Disconnected 12 battery and car reset. No issues since.
Country
New Zealand
Model year
2016
Month of manufacture
[no answer provided]
The 5-digit “brake firmware” code as displayed via the “ECU versions” service screen on LeafSpy at the time of failure
NA don’t have leaf spy pro
“Brake” codes that you can see on the “DTCs” service screen on LeafSpy
[no answer provided]
Has your Leaf experienced a brake system failure/s?
Yes, just one. (please provide details below)
What was the outside temperature when your failure/s occured?
Moderate
Shortly before or after the failure/s, did you find out that your 12V battery was very degraded?
No
Shortly before or after the failure/s, did you disconnect the 12V battery?
[no answer provided]
Do you recall seeing any warning lights before the failure/s?
No
Do you recall seeing any warning lights during and/or after the failure/s?
[no answer provided]
How fast were you driving at the time of the failure/s?
Problem arose when staring after work
When the failure/s occurred, did you hear strange noises from under the bonnet?
[no answer provided]
How did you come to a stop?
Heavy pressing is pedal
As you were stopping, was there a juddering halt, or a smooth one?
[no answer provided]
Was anyone injured?
No
Was any vehicle/property damaged?
No
Did you report the failure/s to a Nissan-authorised service centre or dealer (hereafter, just “Nissan”)?
No
Was the failure reported to an authority/ies other than Nissan? If so, who?
No
What did Nissan do by way of remedy?
[no answer provided]
Was there a cost for this remedy?
None. Car reset via battery disconnection worked
Has your e-ACT Electrically-driven Intelligent Brake Control Unit been replaced completely?
No
Is there anything we missed?
[no answer provided]
Flip The Fleet’s own classification of this case
EDIB Fault
Reversing out of garage and there was a strange noise when brake pedal was depressed. A lot more force on the pedal than usual was required to stop the car.
Country
New Zealand
Model year
2015
Month of manufacture
February
The 5-digit “brake firmware” code as displayed via the “ECU versions” service screen on LeafSpy at the time of failure
3NG9B
“Brake” codes that you can see on the “DTCs” service screen on LeafSpy
[no answer provided]
Has your Leaf experienced a brake system failure/s?
Yes, just one. (please provide details below)
What was the outside temperature when your failure/s occured?
Moderate
Shortly before or after the failure/s, did you find out that your 12V battery was very degraded?
Yes
Shortly before or after the failure/s, did you disconnect the 12V battery?
[no answer provided]
Do you recall seeing any warning lights before the failure/s?
I don’t remember
Do you recall seeing any warning lights during and/or after the failure/s?
I don’t remember
How fast were you driving at the time of the failure/s?
Reversing speed
When the failure/s occurred, did you hear strange noises from under the bonnet?
[no answer provided]
How did you come to a stop?
Heavy foot on brake
As you were stopping, was there a juddering halt, or a smooth one?
[no answer provided]
Was anyone injured?
No
Was any vehicle/property damaged?
No
Did you report the failure/s to a Nissan-authorised service centre or dealer (hereafter, just “Nissan”)?
No
Was the failure reported to an authority/ies other than Nissan? If so, who?
Alistair Gilmore
What did Nissan do by way of remedy?
New software update has been installed
Was there a cost for this remedy?
230
Has your e-ACT Electrically-driven Intelligent Brake Control Unit been replaced completely?
No
Is there anything we missed?
[no answer provided]
Flip The Fleet’s own classification of this case
EDIB Fault
My brakes have not come on when expected about 4 times in 18 months. Most recently twice on the same day. Travelling down hill at approximately 40 – 50kmph. Put foot on brake peddle and got no response. Push harder and brakes come on. Both times, there has not been time to release peddle and try again. Usually any problem I have with my brakes is the opposite of this, when they grab with the slightest pressure on the peddle and nearly send me through the windscreen. This is resolved by releasing the peddle completely and then braking again. I would say this has happened about 100 times in 18 months.
Country
New Zealand
Model year
2014
Month of manufacture
[no answer provided]
The 5-digit “brake firmware” code as displayed via the “ECU versions” service screen on LeafSpy at the time of failure
[no answer provided]
“Brake” codes that you can see on the “DTCs” service screen on LeafSpy
[no answer provided]
Has your Leaf experienced a brake system failure/s?
Yes, a few! (please provide details below)
What was the outside temperature when your failure/s occured?
Moderate
Shortly before or after the failure/s, did you find out that your 12V battery was very degraded?
No
Shortly before or after the failure/s, did you disconnect the 12V battery?
[no answer provided]
Do you recall seeing any warning lights before the failure/s?
No
Do you recall seeing any warning lights during and/or after the failure/s?
No
How fast were you driving at the time of the failure/s?
No brakes 50 kph. Grabbing brakes usually below 20 kph but can happen at faster pace as well
When the failure/s occurred, did you hear strange noises from under the bonnet?
[no answer provided]
How did you come to a stop?
push harder on peddle
As you were stopping, was there a juddering halt, or a smooth one?
[no answer provided]
Was anyone injured?
no
Was any vehicle/property damaged?
no
Did you report the failure/s to a Nissan-authorised service centre or dealer (hereafter, just “Nissan”)?
No
Was the failure reported to an authority/ies other than Nissan? If so, who?
no
What did Nissan do by way of remedy?
[no answer provided]
Was there a cost for this remedy?
[no answer provided]
Has your e-ACT Electrically-driven Intelligent Brake Control Unit been replaced completely?
No
Is there anything we missed?
[no answer provided]
Flip The Fleet’s own classification of this case
EDIB Fault
This next set of case studies reflect a variety of other types of brake fault; some of them may involve another type of EDIB fault, but insufficient information is available to categorise them further:
When braking to slow down, the car does not slow down. This happens especially going downhill, parking or preparing to stop at an intersection. It feels like the car dives forward more than usual when the brake is applied (the opposite of what the brakes should be doing). My partner was driving the Leaf last week, and actually ended up in the middle of the intersection as she couldn’t stop in time. The brake pedal just feels really stiff at the top of the stoke.
Country
New Zealand
Model year
2014
Month of manufacture
April
The 5-digit “brake firmware” code as displayed via the “ECU versions” service screen on LeafSpy at the time of failure
3NG5A
“Brake” codes that you can see on the “DTCs” service screen on LeafSpy
OK NONE
Has your Leaf experienced a brake system failure/s?
Yes, a few! (please provide details below)
What was the outside temperature when your failure/s occured?
Warm
Shortly before or after the failure/s, did you find out that your 12V battery was very degraded?
I don’t remember
Shortly before or after the failure/s, did you disconnect the 12V battery?
Neither
Do you recall seeing any warning lights before the failure/s?
No
Do you recall seeing any warning lights during and/or after the failure/s?
No
How fast were you driving at the time of the failure/s?
50kph or less
When the failure/s occurred, did you hear strange noises from under the bonnet?
No, no noises at all
How did you come to a stop?
Press down really hard on the brake
As you were stopping, was there a juddering halt, or a smooth one?
Juddering halt
Was anyone injured?
No
Was any vehicle/property damaged?
No
Did you report the failure/s to a Nissan-authorised service centre or dealer (hereafter, just “Nissan”)?
No
Was the failure reported to an authority/ies other than Nissan? If so, who?
No
What did Nissan do by way of remedy?
NA
Was there a cost for this remedy?
NA
Has your e-ACT Electrically-driven Intelligent Brake Control Unit been replaced completely?
No
Is there anything we missed?
[no answer provided]
Flip The Fleet’s own classification of this case
Other
My leaf was involved in an accident directly due to the brake failure but indirectly also due to a much less frequent though documented design defect. The vehicle was put into a skid entirely because of erroneous operation of the VDC I corrected the skid and regained control of the vehicle but during the process it had gone over a kerb causing a vertical jolt which I believe instigated the brake failure. After correcting the skid, as I headed towards a house, with ample room to stop under normal circumstances, I realised that I had no brakes. Pressing the brake pedal as hard as i could it just felt solid and there was no slowing of the vehicle until it ran into a wooden wall. After the accident the brakes returned to perfectly normal operation
Country
New Zealand
Model year
2014
Month of manufacture
December
The 5-digit “brake firmware” code as displayed via the “ECU versions” service screen on LeafSpy at the time of failure
3NG9A
“Brake” codes that you can see on the “DTCs” service screen on LeafSpy
C1109 0008 ABS Battery Voltage Abnormal BRC-75 C118C 0108 ABS EV/HEV System BRC-126 C1A62 0108 BRAKE Control Mod Pwr Supply BR-53 C1A6E 0108 BRAKE EV/HEV System BR-146 C1A70 0108 BRAKE Brake Control System BR-160
Has your Leaf experienced a brake system failure/s?
Yes, just one. (please provide details below)
What was the outside temperature when your failure/s occured?
Moderate
Shortly before or after the failure/s, did you find out that your 12V battery was very degraded?
Yes, after
Shortly before or after the failure/s, did you disconnect the 12V battery?
Yes, after
Do you recall seeing any warning lights before the failure/s?
No
Do you recall seeing any warning lights during and/or after the failure/s?
No
How fast were you driving at the time of the failure/s?
Around 15kph before the brake failure, most of the inertia from the previous speed of 50kpn having been lost in the skid and bumping the kerb
When the failure/s occurred, did you hear strange noises from under the bonnet?
No, no noises at all
How did you come to a stop?
Hit the wall
As you were stopping, was there a juddering halt, or a smooth one?
Smooth halt
Was anyone injured?
My thumbs on the steering wheel and severe psychologial injury leading to extended period of PTSD – still undergoing treatment
Was any vehicle/property damaged?
Yes
Did you report the failure/s to a Nissan-authorised service centre or dealer (hereafter, just “Nissan”)?
Yes
Was the failure reported to an authority/ies other than Nissan? If so, who?
Importer [company redacted] virtually laughed at me. NZTA not adequately resourced to investigate
What did Nissan do by way of remedy?
Offered to investigate at my expense but without permission for me to observe or for me to be permitted to interview technician
Was there a cost for this remedy?
I declined their ‘offer’
Has your e-ACT Electrically-driven Intelligent Brake Control Unit been replaced completely?
No
Is there anything we missed?
Managing Director of Nissan NZ responded that they have no liability as they didn’t import the vehicle and added that they never imported the ‘gen 2’ Leaf as they were not satisfied with its safety standards The day after I spoke to him I approached a local Nissan dealer with a view to negotiating a joint investigation of the problem (as I am highly technically qualified) and it was clear to me that they had already been warned about me and instructed how to deal with me. (And probably by email to every nissan dealer in the country!) I am not normally a conspiracy theorist but I do believe that Nissan has taken the decision to be in denial. I’m surprised they are getting away with this in the US, but Volkswagen did, until caught by highly qualified scientists over their diesel fraud The level of disinterest and deliberate obstacles I encountered with NZTA led me to suspect possible vested interests in not upsetting a car giant, but their recent display of of incompetence over wof testing makes me feel I should favour the cock-up theory over machiavellianism! I have personally encountered complete dishonesty in another high profile Japanese manufacturer in trying to hide product deficiencies in the field I use to work in, top end broadcast television The recently sacked head of Nissan didn’t exactly symbolise honesty in his behaviour!
Flip The Fleet’s own classification of this case
Other
I guess initially it was my fault, I got distracted and accidentally hit a concrete column while heading out of the parking area. It was in my office building so I was driving at a speed of less than 10km/hr. I was intending to get off the car to check the (supposedly minor) damage but the car started to move backwards while I was stepping on the brake! It hit the wall behind me and then started accelerating forward again, I was so scared, I was desperately pulling the hand break and pressing the park button but none of it was working. Finally, the car smashed hard on another concrete column and stopped moving. I was lucky enough that the air bag worked, that nobody got injured and no other vehicle got involved. It was as if it self-destructed after the first impact. My motor insurance company has decided for the car to be written off because it was badly damaged. When I called Nissan to report the incident they did not sound convinced. They told me that they have never heard anything like this before and that they cannot do anything about it unless I will file an official report so that the authorities will require them to conduct an investigation or take action. I was too busy during that period and could not be bothered, I was given restricted time to decide whether to just move forward and get my insurance to pay me for a replacement car or go on with the investigation (at my cost).
Country
Auckland
Model year
2011
Month of manufacture
September
The 5-digit “brake firmware” code as displayed via the “ECU versions” service screen on LeafSpy at the time of failure
[no answer provided]
“Brake” codes that you can see on the “DTCs” service screen on LeafSpy
[no answer provided]
Has your Leaf experienced a brake system failure/s?
Yes, just one. (please provide details below)
What was the outside temperature when your failure/s occured?
Moderate
Shortly before or after the failure/s, did you find out that your 12V battery was very degraded?
Neither
Shortly before or after the failure/s, did you disconnect the 12V battery?
Neither
Do you recall seeing any warning lights before the failure/s?
No
Do you recall seeing any warning lights during and/or after the failure/s?
No
How fast were you driving at the time of the failure/s?
Less than 10kph
When the failure/s occurred, did you hear strange noises from under the bonnet?
No, no noises at all
How did you come to a stop?
By crashing on a concrete column
As you were stopping, was there a juddering halt, or a smooth one?
I don’t remember
Was anyone injured?
None
Was any vehicle/property damaged?
None
Did you report the failure/s to a Nissan-authorised service centre or dealer (hereafter, just “Nissan”)?
Yes
Was the failure reported to an authority/ies other than Nissan? If so, who?
No
What did Nissan do by way of remedy?
Nothing, they said they have never heard something like this before
Was there a cost for this remedy?
[no answer provided]
Has your e-ACT Electrically-driven Intelligent Brake Control Unit been replaced completely?
No
Is there anything we missed?
[no answer provided]
Flip The Fleet’s own classification of this case
Other
2011 Nissan Leaf G Model – Ex-Japan Import to New Zealand.
The car has had an intermittent issue with the brakes since we imported it in April 2015. The issue is that on approximately 10% of start ups the car appears to have no powered assisted braking or brake pedal activated regeneration for the duration of the journey. The brakes feel less responsive and more pedal force than normal is required to stop the car.
The system only returns to normal once the car has been powered off for approx 10 minutes or more. Motor regeneration during brakes-off deceleration stays active and is not affected. On one occasion that I am aware of (I am not the primary driver of the vehicle) the cars brake pedal has gone straight to the floor with little resistance or vehicle braking activity.
I pumped the brakes quickly and managed to get up enough pressure stop the car before almost rear ending the vehicle stopping at the intersection in front of me.- my heart was in my mouth – and my Family was somewhat distressed.
With the car stationary I then proceeded to push the brake pedal to the floor again with little effort. Pumping the brake pedal twice more the pressure returned to normal the brakes firmed up giving me enough confidence to drive the remaining 500m to my house where I promptly interrogated the the ECU fault codes via Leafspy Pro before de-powering the car. No fault codes were evident. I re-powered the car and took it for another drive. No faults evident. Braking normal and pedal felt firm.
Vehicle speed was approx 40 kph and it was during a fine clear day with an ambient temperature above 10 degrees Celsius. This was in late 2015 early 2016. I then proceeded to research the issue on the internet and found similar stories overseas. I noted a firmware update had been rolled out overseas to fix the issue but with limited success. Most owners noted a decrease in the vehicle acceleration performance post the update rather than a fix for the brakes. I also noted online comments on suspected 12v battery health as a suspected cause – but at the time ours was only about 6 months old.
I did however put the 12v battery on an external 2.2amp charger for a few hours and noted it took about 2-3 hours to appear fully charged. I have since externally charged the 12v batteries in both our Leafs monthly, as the lower on-board charging voltage appears to be less than ideal and parasitic loads mean the 12v batteries do require a top up with an external charger at 14.5 volts occasionally.I do this to extend the life of the 12v battery and to prevent any 12v related system issues – brakes included.
Personal observations only.
Country
New Zealand
Model year
2011
Month of manufacture
October
The 5-digit “brake firmware” code as displayed via the “ECU versions” service screen on LeafSpy at the time of failure
3NB0A
“Brake” codes that you can see on the “DTCs” service screen on LeafSpy
OK NONE
Has your Leaf experienced a brake system failure/s?
Yes, just one. (please provide details below)
What was the outside temperature when your failure/s occured?
Moderate
Shortly before or after the failure/s, did you find out that your 12V battery was very degraded?
Yes, after
Shortly before or after the failure/s, did you disconnect the 12V battery?
Neither
Do you recall seeing any warning lights before the failure/s?
No
Do you recall seeing any warning lights during and/or after the failure/s?
No
How fast were you driving at the time of the failure/s?
40 kph
When the failure/s occurred, did you hear strange noises from under the bonnet?
No, no noises at all
How did you come to a stop?
Pumped the brakes until some pressure was felt. When the car stopped I was able to push the pedal to the floor again with little resistance.
As you were stopping, was there a juddering halt, or a smooth one?
Smooth halt
Was anyone injured?
No
Was any vehicle/property damaged?
No
Did you report the failure/s to a Nissan-authorised service centre or dealer (hereafter, just “Nissan”)?
No
Was the failure reported to an authority/ies other than Nissan? If so, who?
No
What did Nissan do by way of remedy?
N/A
Was there a cost for this remedy?
N/A
Has your e-ACT Electrically-driven Intelligent Brake Control Unit been replaced completely?
No
Is there anything we missed?
Occasionally the brakes get touchy at low speed (20kph or less), and will grab violently. I find slamming the brakes on at low speed (50 kph or less) to the point where the Anti-skid system is exercised appears to clear the issue. I have also had to do this on my 2012 Leaf on a couple of occasions.
Flip The Fleet’s own classification of this case
Other (Gen 1.1)
Approx 3 failures experienced prior to replacing 12V battery due to reports of erratic electronic gremlins if 12V was failing. Car starts normally, then when entering either D or R, is not possible to stop with any amount of brake force. Fortunately this only happened from standing start, I was able to stop by hitting P or turning the ignition off, which seemed to have the same effect. Park brake (electronic on this one, not foot) seemed to have no effect.
Country
New Zealand
Model year
2012
Month of manufacture
2
The 5-digit “brake firmware” code as displayed via the “ECU versions” service screen on LeafSpy at the time of failure
3NA03
“Brake” codes that you can see on the “DTCs” service screen on LeafSpy
[no answer provided]
Has your Leaf experienced a brake system failure/s?
Yes, a few! (please provide details below)
What was the outside temperature when your failure/s occured?
Moderate
Shortly before or after the failure/s, did you find out that your 12V battery was very degraded?
Yes, after
Shortly before or after the failure/s, did you disconnect the 12V battery?
Yes, after
Do you recall seeing any warning lights before the failure/s?
Yes (if you remember, please tell us which light/s as a comment)
Do you recall seeing any warning lights during and/or after the failure/s?
Yes (if you remember, please tell us which light/s as a comment)
How fast were you driving at the time of the failure/s?
5 km/h max
When the failure/s occurred, did you hear strange noises from under the bonnet?
I don’t remember
How did you come to a stop?
Selecting P or switching off ignition
As you were stopping, was there a juddering halt, or a smooth one?
Juddering halt
Was anyone injured?
No
Was any vehicle/property damaged?
No
Did you report the failure/s to a Nissan-authorised service centre or dealer (hereafter, just “Nissan”)?
No
Was the failure reported to an authority/ies other than Nissan? If so, who?
No
What did Nissan do by way of remedy?
[no answer provided]
Was there a cost for this remedy?
[no answer provided]
Has your e-ACT Electrically-driven Intelligent Brake Control Unit been replaced completely?
No
Is there anything we missed?
I recall thag the orange triangle and orange EPS lights were on at the time of each failure. We didn’t report it as replacing the 12V battery made it go away.
Flip The Fleet’s own classification of this case
Other (Gen 1.1)
We have owned our imported 2016 Nissan Leaf Tekna (UK) for over 12 months now, and have had no issues with anything. The BMS system was software upgraded when it became available.
Today I experienced brake fade whilst driving in traffic at about 20 to 25 kph, slightly downhill in B-mode. It was raining and the road was wet and the temperature in Wellington was about 12degC. It took about 20 to 30 metres to come to a standstill.
This was not ABS operating as I know what that is and there was no vibration or shaking, simply an extremely hard brake pedal and very little braking regardless of how hard I pressed on the brake pedal. It is not possible for water to be on the disc rotors as the brakes were working normally immediately prior, and worked normally again after eventually stopping.
It was very similar to a vehicle with vaccuum power assisted brakes and the engine off.
There were no warning messages or signs on the dashboard.
I understand there is a software upgrade available for the brake system.
Country
New Zealand
Model year
2016
Month of manufacture
probably early 2016
The 5-digit “brake firmware” code as displayed via the “ECU versions” service screen on LeafSpy at the time of failure
4NR0A
“Brake” codes that you can see on the “DTCs” service screen on LeafSpy
[no answer provided]
Has your Leaf experienced a brake system failure/s?
Yes, just one. (please provide details below)
What was the outside temperature when your failure/s occured?
Moderate
Shortly before or after the failure/s, did you find out that your 12V battery was very degraded?
Neither
Shortly before or after the failure/s, did you disconnect the 12V battery?
Neither
Do you recall seeing any warning lights before the failure/s?
No
Do you recall seeing any warning lights during and/or after the failure/s?
No
How fast were you driving at the time of the failure/s?
20 to 25 kph
When the failure/s occurred, did you hear strange noises from under the bonnet?
No, no noises at all
How did you come to a stop?
Slowly, it was very smooth and quiet and very scary despite the high foot pressure applied to the brake pedal
As you were stopping, was there a juddering halt, or a smooth one?
Smooth halt
Was anyone injured?
No
Was any vehicle/property damaged?
No but it took about 20 to 30 metres on a slight downhill from 20 to 25 kph to come to a standstill
Did you report the failure/s to a Nissan-authorised service centre or dealer (hereafter, just “Nissan”)?
No
Was the failure reported to an authority/ies other than Nissan? If so, who?
Not yet
What did Nissan do by way of remedy?
[no answer provided]
Was there a cost for this remedy?
[no answer provided]
Has your e-ACT Electrically-driven Intelligent Brake Control Unit been replaced completely?
No
Is there anything we missed?
Now drive in D-mode so no regenerative braking with foot off or only lightly applied to the brake pedal. In B-mode there feels like there is a delay or “sticky pedal” when changing over from regenerative braking to combined mechanical and regenerative braking, that is not present in D-mode.
Flip The Fleet’s own classification of this case
Other
3 issues around braking
1. Backing slowly downhill a couple of times with the car in neutral (so as not to wake the baby with the internal beeping) when the car has just been started, there can be a juddery, whiney gear type noise when you apply the brakes which sounds bad and you can feel through the pedal. Almost like the ABS kicking in. Very low speed – under 10km/h.
2. I’ve noticed the car will change from what feels like normal motor regen+brake regen to just friction brakes when you are already braking and hit a bump in the road or even go around a corner and downhill braking. This is at low speeds 30-60km/h. Not great when you come around a corner, down the hill and there is a cue of cars you brake for, then suddenly lose most of your braking force when all the regen goes off and have to stand on the brakes more. This isn’t just when the battery charge is high. Can do it at 50% battery. Mostly noticed on cold mornings but haven’t tried to replicate now its warmer. You can see it on the dash too as the regen dots disapear and you are still having to slow down.
3. High speed chipseal road driving and braking while hitting a bump does the same thing where the regen just cuts out and you have to really get on the brake pedal compared to normal to slow down. It can do it even going over a join onto a bridge. From memory, only been happening after some extended highway driving followed by braking where we need to come almost or completely to a stop. Usually when I’ve had a car load of family and things. Similar to the low speed one above.
Country
NZL
Model year
2016
Month of manufacture
April
The 5-digit “brake firmware” code as displayed via the “ECU versions” service screen on LeafSpy at the time of failure
4NN1C
“Brake” codes that you can see on the “DTCs” service screen on LeafSpy
Ok None (probably been cleared along the way if there was any)
Has your Leaf experienced a brake system failure/s?
Yes, a few! (please provide details below)
What was the outside temperature when your failure/s occured?
Moderate
Shortly before or after the failure/s, did you find out that your 12V battery was very degraded?
Neither
Shortly before or after the failure/s, did you disconnect the 12V battery?
Neither
Do you recall seeing any warning lights before the failure/s?
No
Do you recall seeing any warning lights during and/or after the failure/s?
No
How fast were you driving at the time of the failure/s?
Variety of speeds from approx 10km/h to 100km/h
When the failure/s occurred, did you hear strange noises from under the bonnet?
Yes
How did you come to a stop?
Press really hard on the brake compared to normal
As you were stopping, was there a juddering halt, or a smooth one?
Smooth halt
Was anyone injured?
No
Was any vehicle/property damaged?
No
Did you report the failure/s to a Nissan-authorised service centre or dealer (hereafter, just “Nissan”)?
No
Was the failure reported to an authority/ies other than Nissan? If so, who?
No
What did Nissan do by way of remedy?
[no answer provided]
Was there a cost for this remedy?
[no answer provided]
Has your e-ACT Electrically-driven Intelligent Brake Control Unit been replaced completely?
No
Is there anything we missed?
I believe you wrote the ‘C’ brake firmware was alright but mine still isn’t 100%. Its quite rarely it will do strange things, but it still does.
Flip The Fleet’s own classification of this case
Other
Noticed when parked occasionally and also when I had a flat 12v battery. Never when actually being driven.apart from slow reverse.
Country
NZ
Model year
2016
Month of manufacture
Not available
The 5-digit “brake firmware” code as displayed via the “ECU versions” service screen on LeafSpy at the time of failure
3NG9A
“Brake” codes that you can see on the “DTCs” service screen on LeafSpy
[no answer provided]
Has your Leaf experienced a brake system failure/s?
Yes, just one. (please provide details below)
What was the outside temperature when your failure/s occured?
Moderate
Shortly before or after the failure/s, did you find out that your 12V battery was very degraded?
Yes, after
Shortly before or after the failure/s, did you disconnect the 12V battery?
Yes, after
Do you recall seeing any warning lights before the failure/s?
No
Do you recall seeing any warning lights during and/or after the failure/s?
No
How fast were you driving at the time of the failure/s?
Reversing under 5kph
When the failure/s occurred, did you hear strange noises from under the bonnet?
No, no noises at all
How did you come to a stop?
Reversing from car park pushed harder on brake pedal.
As you were stopping, was there a juddering halt, or a smooth one?
I don’t remember
Was anyone injured?
No
Was any vehicle/property damaged?
No
Did you report the failure/s to a Nissan-authorised service centre or dealer (hereafter, just “Nissan”)?
No
Was the failure reported to an authority/ies other than Nissan? If so, who?
No
What did Nissan do by way of remedy?
[no answer provided]
Was there a cost for this remedy?
[no answer provided]
Has your e-ACT Electrically-driven Intelligent Brake Control Unit been replaced completely?
[no answer provided]
Is there anything we missed?
The failures when I think back to it happened when reversing and were just after purchase when the 12v battery was getting flat. After testing battery it wouldn’t hold a charge and was replaced. Since then I have not had any problem but when it happened it was a little scary!!
Flip The Fleet’s own classification of this case
Other
Not a full on failure but have had brake fade, as if there is no or little power to the brakes and had to push hard to get the vehicle to stop. in reverse (backing down driveway) almost at times have very little braking power.
Country
New Zealand
Model year
2013
Month of manufacture
[no answer provided]
The 5-digit “brake firmware” code as displayed via the “ECU versions” service screen on LeafSpy at the time of failure
3NG4A
“Brake” codes that you can see on the “DTCs” service screen on LeafSpy
[no answer provided]
Has your Leaf experienced a brake system failure/s?
Yes, a few! (please provide details below)
What was the outside temperature when your failure/s occured?
I don’t remember
Shortly before or after the failure/s, did you find out that your 12V battery was very degraded?
I don’t remember
Shortly before or after the failure/s, did you disconnect the 12V battery?
[no answer provided]
Do you recall seeing any warning lights before the failure/s?
No
Do you recall seeing any warning lights during and/or after the failure/s?
No
How fast were you driving at the time of the failure/s?
45 to stop very faded brakes
When the failure/s occurred, did you hear strange noises from under the bonnet?
[no answer provided]
How did you come to a stop?
on the brakes but eventually
As you were stopping, was there a juddering halt, or a smooth one?
[no answer provided]
Was anyone injured?
no
Was any vehicle/property damaged?
no
Did you report the failure/s to a Nissan-authorised service centre or dealer (hereafter, just “Nissan”)?
No
Was the failure reported to an authority/ies other than Nissan? If so, who?
no
What did Nissan do by way of remedy?
[no answer provided]
Was there a cost for this remedy?
[no answer provided]
Has your e-ACT Electrically-driven Intelligent Brake Control Unit been replaced completely?
No
Is there anything we missed?
no
Flip The Fleet’s own classification of this case
Other
One day, after a QC the break starte to sound like some one drag kin a chain thru a pipe. and in sted of glente brakeing. is slam. The Error disappeared by unhock 12v for some time.. (or that what the shop say..)
Country
Denmark
Model year
2016
Month of manufacture
November 2015
The 5-digit “brake firmware” code as displayed via the “ECU versions” service screen on LeafSpy at the time of failure
3nf9b
“Brake” codes that you can see on the “DTCs” service screen on LeafSpy
[no answer provided]
Has your Leaf experienced a brake system failure/s?
Yes, just one. (please provide details below)
What was the outside temperature when your failure/s occured?
Cold
Shortly before or after the failure/s, did you find out that your 12V battery was very degraded?
No
Shortly before or after the failure/s, did you disconnect the 12V battery?
[no answer provided]
Do you recall seeing any warning lights before the failure/s?
No
Do you recall seeing any warning lights during and/or after the failure/s?
No
How fast were you driving at the time of the failure/s?
0kph
When the failure/s occurred, did you hear strange noises from under the bonnet?
[no answer provided]
How did you come to a stop?
.
As you were stopping, was there a juddering halt, or a smooth one?
[no answer provided]
Was anyone injured?
no
Was any vehicle/property damaged?
no
Did you report the failure/s to a Nissan-authorised service centre or dealer (hereafter, just “Nissan”)?
Yes
Was the failure reported to an authority/ies other than Nissan? If so, who?
no
What did Nissan do by way of remedy?
could not explain the error, but it disappeared
Was there a cost for this remedy?
0kr
Has your e-ACT Electrically-driven Intelligent Brake Control Unit been replaced completely?
No
Is there anything we missed?
4 day in the shop.
and please send the recal-report number to bring to Nissan (local dealer is not in to EV’s yet) show i can ask for this update to be appayt to my car.
Flip The Fleet’s own classification of this case
Other (Overseas)
Not sure if a failure or not. I experienced a noticeable drop in braking performance on a couple of occasions.
Country
New Zealand
Model year
2016
Month of manufacture
201512
The 5-digit “brake firmware” code as displayed via the “ECU versions” service screen on LeafSpy at the time of failure
4NN1A
“Brake” codes that you can see on the “DTCs” service screen on LeafSpy
[no answer provided]
Has your Leaf experienced a brake system failure/s?
Yes, just one. (please provide details below)
What was the outside temperature when your failure/s occured?
Moderate
Shortly before or after the failure/s, did you find out that your 12V battery was very degraded?
No
Shortly before or after the failure/s, did you disconnect the 12V battery?
[no answer provided]
Do you recall seeing any warning lights before the failure/s?
No
Do you recall seeing any warning lights during and/or after the failure/s?
No
How fast were you driving at the time of the failure/s?
30 kph
When the failure/s occurred, did you hear strange noises from under the bonnet?
[no answer provided]
How did you come to a stop?
Continued to apply brakes and they seemed to recover
As you were stopping, was there a juddering halt, or a smooth one?
[no answer provided]
Was anyone injured?
No
Was any vehicle/property damaged?
No
Did you report the failure/s to a Nissan-authorised service centre or dealer (hereafter, just “Nissan”)?
No
Was the failure reported to an authority/ies other than Nissan? If so, who?
No
What did Nissan do by way of remedy?
[no answer provided]
Was there a cost for this remedy?
[no answer provided]
Has your e-ACT Electrically-driven Intelligent Brake Control Unit been replaced completely?
No
Is there anything we missed?
Not sure if I have a problem or not. Symptoms are a little different to yours.
Flip The Fleet’s own classification of this case
Other
Brake seems unresponsive with light pressure and often have to do a hard press for brakes to engage. This causes all occupants to lurch forward.
Country
New Zealand
Model year
2014
Month of manufacture
September
The 5-digit “brake firmware” code as displayed via the “ECU versions” service screen on LeafSpy at the time of failure
Don’t have leafspy pro
“Brake” codes that you can see on the “DTCs” service screen on LeafSpy
[no answer provided]
Has your Leaf experienced a brake system failure/s?
Yes, just one. (please provide details below)
What was the outside temperature when your failure/s occured?
Warm
Shortly before or after the failure/s, did you find out that your 12V battery was very degraded?
No
Shortly before or after the failure/s, did you disconnect the 12V battery?
[no answer provided]
Do you recall seeing any warning lights before the failure/s?
No
Do you recall seeing any warning lights during and/or after the failure/s?
No
How fast were you driving at the time of the failure/s?
10km
When the failure/s occurred, did you hear strange noises from under the bonnet?
[no answer provided]
How did you come to a stop?
Hard brake
As you were stopping, was there a juddering halt, or a smooth one?
[no answer provided]
Was anyone injured?
No
Was any vehicle/property damaged?
No
Did you report the failure/s to a Nissan-authorised service centre or dealer (hereafter, just “Nissan”)?
No
Was the failure reported to an authority/ies other than Nissan? If so, who?
No
What did Nissan do by way of remedy?
Na
Was there a cost for this remedy?
No
Has your e-ACT Electrically-driven Intelligent Brake Control Unit been replaced completely?
No
Is there anything we missed?
[no answer provided]
Flip The Fleet’s own classification of this case
Other
2014 Model S. Had a number of oddities with what I thought was some sort of brake fade since I have owned it for a few months. Wasn’t influenced by social media or other comments as was noticeable well before hearing reports of brake oddities. Had mentioned it to a number of people, and thought maybe I was imagining it! Was worried enough to tell my wife to ‘be wary’ when she was driving it – occasionally you need to put a lot more pressure on the brakes than you expect you have to.
The most recent (and also most noticeable – some are worse than others) event was around 8 days ago, exiting the motorway and on a long down hill offramp (Wellesley St, Akl) approx 8am. I went to press the brakes to slow down and it almost felt like there was no power assist at all. The issue has occurred possibly 5-6 times in the last 3 months I’ve had it. It ‘seems’ to be downhill only, which is why I am wary slowing down after a downhill run in traffic (lots of regen?). I don’t find it too much of a problem currently as I am wary of it, but it would certainly be an issue for someone else if good following distances weren’t maintained and they weren’t aware of it. I would ensure I tell anyone else who was to drive it. It would be nice to get it solved however.
Country
New Zealand
Model year
2014
Month of manufacture
[no answer provided]
The 5-digit “brake firmware” code as displayed via the “ECU versions” service screen on LeafSpy at the time of failure
3NG5A
“Brake” codes that you can see on the “DTCs” service screen on LeafSpy
[no answer provided]
Has your Leaf experienced a brake system failure/s?
Yes, a few! (please provide details below)
What was the outside temperature when your failure/s occured?
Moderate
Shortly before or after the failure/s, did you find out that your 12V battery was very degraded?
No
Shortly before or after the failure/s, did you disconnect the 12V battery?
[no answer provided]
Do you recall seeing any warning lights before the failure/s?
No
Do you recall seeing any warning lights during and/or after the failure/s?
No
How fast were you driving at the time of the failure/s?
20km/h
When the failure/s occurred, did you hear strange noises from under the bonnet?
[no answer provided]
How did you come to a stop?
More brake pressure
As you were stopping, was there a juddering halt, or a smooth one?
[no answer provided]
Was anyone injured?
no
Was any vehicle/property damaged?
no
Did you report the failure/s to a Nissan-authorised service centre or dealer (hereafter, just “Nissan”)?
No
Was the failure reported to an authority/ies other than Nissan? If so, who?
no
What did Nissan do by way of remedy?
n/a
Was there a cost for this remedy?
n/a
Has your e-ACT Electrically-driven Intelligent Brake Control Unit been replaced completely?
No
Is there anything we missed?
[no answer provided]
Flip The Fleet’s own classification of this case
Other
We have redacted personal contact details and one field where the respondents provided comments that they did not want to be made public, and lightly edited the description to remove personal identifiers. Otherwise this is a complete and unedited version of what was submitted.
Classification of fault types
Our initial five reported cases were all EDIB unit faults, as signified by DTCs from other control modules in the vehicle indicating that communication with the EDIB had been lost. This fault had been reported by drivers as being characterised by significant extra pedal travel and the perception that little or no braking was available. Since then, drivers have reported a variety of unexpected braking behaviours some of which may not be related to a fault of the EDIB. Only some owners have been able to provide a list of DTCs that were present following the incident, so when there are no DTCs provided we cannot confirm whether the car has logged a fault at some point in time. For simplicity, we will use the following symptoms to categorise reports into two main categories, where one or a few symptoms may be enough to classify as a fault:
“EDIB Fault” = Loss of Brake Boost from the EDIB
- Increased pedal travel with surprise factor when no brakes initially felt
- A feeling of not being able to stop even when pushing hard
- Warning lights for Brake and/or ABS
- DTCs (when provided) relating to other systems being unable to communicate with the EDIB unit (and lack of EDIB unit)
- Irregular brake pedal force feedback or shuddering
- Audible noises (e.g. graunching sound) from brake unit area or behind glovebox with higher brake pedal travel (i.e. not normal ABS action)
The overseas evidence suggests that these EDIB faults are primarily occurring in Gen 1.2 and 1.3 Nissan Leafs manufactured between November 2012 and February 2016 (Appendix 4 gives examples). We have so far received 9 reports of faults in New Zealand that are in this category.
The reporting from both overseas and local experience suggests that during an EDIB fault there are multiple possible responses from the car. Based on our testing, two distinctly different states were observed from the same car: one where the car arrested much more easily and more quickly than the other. These different states are documented here to highlight the extent of variability that may be observed under an EDIB fault:
1) Irregular Pedal Travel and Significant Shuddering Observed
- Increased pedal travel with surprise factor when no brakes initially felt
- Pedal feedback force varying, shuddering effect and audible noises
- Observed as a consistent response during our tests 10 November 2018 but only some of our testing on 24 November 2018
- Reported by other drivers
- Stopping distances increased but still reasonable during our tests of 10 November
- Aligns with some symptoms observed by NZTA during their test (see Appendix 3)
- More pedal pressure required but during our testing the pedal pressure was not excessive (one of our tests at 50 km/h required about 15 kg for firm stopping)
In their original response (download Communications memo 1) Nissan stated that under a fault state the “brake system may switch to a special ‘assist mode’ ”. We now believe this mode is invoked if the ABS unit recognises a fault condition and uses the internal pump to assist braking, resulting in the shuddering without needing very high pedal pressure.
2) Smoother Braking But High Pedal Pressure Required
- Increased pedal travel with surprise factor when no brakes initially felt
- Believed to be a lack of “assist mode”, ie no “assist” from the ABS withEDIB fault
- There may not be obvious shuddering effect or audible noises
- Braking was available but high pedal force required (estimated as at least 50 kg during our test on 24 November)
- Stopping distances significantly longer (about 6 seconds to stop from 30 km/h during our test on 24 November)
- Believed not to be observed by NZTA during their test described in Appendix 3 (however pedal force required was not documented by NZTA)
- More consistent with driver observations that “extreme” pedal effort required and feeling of no brakes no matter how hard the driver pushed
In our testing, there were obvious major differences in the responses from the same car with an induced EDIB fault during different runs – the car presented different symptoms at different times while the EDIB fault was present, in line with the two states presented above. The special “assist mode” identified by Nissan seems to be playing an important role reducing brake pedal force required in our first state but does not seem to be so effective in the second. The driver reports also suggest they may have experienced both conditions with initial high pressure failing to stop and then more obvious assist when the car was later being moved.
A range of other braking issues were reported which we have categorised as “Other”:
Other Unexpected Brake Behaviours
- Grabby brakes where hypervigilant brake action occurs with limited pedal travel
- A sudden loss of regeneration due to vehicle stability control or other safety system requiring individual control of wheel braking (i.e., after a bump in road or loss of traction)
- A feeling the brakes weren’t working properly but a lack of information to fit the fault criteria above
- Pedal “really stiff” at top of stroke (Case 22) which doesn’t align with known EDIB action
- An absence of any warning lights or fault codes if symptoms not aligned with known EDIB faults
We have included the “Other” reports in the logbook reports both for completeness but also because some might by EDIB faults but lack enough evidence at this time.
‘Case 5’ appears to have failed in a different way from the other EDIB faults i.e. the DTC code C1A83 indicates the EDIB detecting an internal problem, and the brake system does not restore when the 12V battery was disconnected and reconnected. Perhaps this relates to a hardware fault rather than the firmware fault causing the others?
Another case (Case 21) was quite distinct from the others and symptoms suggest multiple faults in the ABS system. The fault codes report errors from both ABS and Brake systems with indications of power supply issues.
Summary of the observed faults and drivers’ reactions
- No one has been injured so far, perhaps because most faults have occurred at relatively low speeds (50 km/h maximum, but many at start up or when slowing down)
- The faults observed so far are not complete “catastrophic brake failure”. Some impaired capacity to arrest the car remains – the critical decision is whether this impaired stopping capacity presents a significant risk to people and property.
- All but three of the 22 cases were for Gen 1.2 Nissan Leafs. Most of these were manufactured between 2013 to 2016, but ‘case 5’ was manufactured in November 2012.
- No MY2013 Gen 1.2 Leafs have reported the EDIB fault so far. More data are needed to be sure if this is a chance sampling effect rather than a signal that the MY2013 built Leafs are not affected.
- Amongst the 9 with EDIB faults, six were running ‘A’ series brake firmware, and no EDU records are available for the remaining three.
- The descriptions of the events leave no doubt of the distress of the affected drivers and potential risk and expense involved:
- one returned the vehicle to the dealer and bought an internal combustion vehicle instead;
- one is urging that no more Leafs are sold until the problem he experienced is fixed;
- one nearly rear-end a truck but was able to veer left into an empty lane and turn left again because the traffic light happened to go green at the same moment; one nearly hit a rapid charging station because the fault occurred as they were pulling in to recharge;
- one ended up in the middle of an intersection and is now too frightened to drive the car;
- one would have incurred over $1,500 in vehicle recovery costs had they not had AA Roadside Recovery policy, and potentially several thousands of dollars in replacing the full brake module.
- At least four drivers reported brake faults to Nissan, and two reported to NZTA, another to VIA, and four to the dealer that they purchased their car from. Most presented their car to a repair agent and until this Flip the Fleet logbook facility was established, such instances have not been drawn to the attention of the authorities.
- Some owners experienced repeated faults.
- Some owners are continuing to drive their vehicle even after experiencing the brake fault.
- DTC records are only available for 10 of the 22 case histories, so certain diagnosis of the causes of the faults is impossible.
- About half (9) of the reported cases align closely with our understanding of the EDIB fault mode, but only 5 of these have documented DTCs to absolutely confirm that they resulted from the EDIB fault condition. The remaining cases had very similar symptoms during the fault, even though no DTCs are available for scrutiny.
- The braking system reset when the 12V battery was disconnected in several of these less certain cases, in the same way as described for the ones with DTC confirmation.
- The 12V battery had been replaced before a EDIB fault in two of the 9 cases, and a weak 12V battery was noted after one of the faults had occurred. A weak or low battery warning had been noted in three of 11 other brake issues.
Discussion and conclusions:
Multiple types of faults
In the spirit of absolute transparency, we have included all instances of brake problems reported to us for this analysis. However, in some instances we only have qualitative information of the drivers to go on, and in most cases gathered months after the incident. Recollection of the details is inevitably uncertain, especially if the drivers got a fright when suddenly finding no or reduced braking power – it will be hard for them to recall the exact responses at a moment of surprise and stress. For example, it is uncertain whether drivers describing their response as having had to press the brake pedal ‘further’ compared to ‘harder’ to stop the vehicle are the same, or whether both were required or even tried during their incident.
Future incidence of EDIB faults
We have been conservative in allocating the faults with incomplete information to the EDIB fault category in order to avoid exaggeration of the potential for there being a problem. Our count of 9 instances and the above incidence predictions should be regarded as a minimum because not all of New Zealand’s Leaf owners will have heard about the logbook, and others may not be willing to fill it in. For example, there are additional mentions in New Zealand EV support group forums of past instances that have not been reported in a logbook form. Also, some of the faults happened multiple times to the same vehicle, but we have counted these as single cases.
When a minimum of 9 incidents are scaled against an estimated 3040 “vehicle years” that 2013-2016 Leafs have been in New Zealand so far, the probability of an EDIB fault occurring is estimated as 0.3% per vehicle per year. A 95% uncertainty interval was calculated to be 0.2% to be 0.6% This means that the EDIB fault rate is likely to be between 0.2% and 0.6%, and we think it will be closest to 0.3%.
The total number of EVs has more than doubled in each of the last three years, and the Gen 1.2 and 1.3 Nissan Leafs are the most common model being imported. Assuming that (i) the number of 2013-2016 Leafs doubles again in the coming year, and that (ii) the probability of a fault of each one remains the same as up until now, we predict (a) an incidence of 11 of this particular fault next year, with (b) a 95% uncertainty interval of [6, 21] faults in the next year. In other words, we can reasonably expect anywhere between 6 and 21 EDIB faults in the coming year, but the most likely number is closer to 11, assuming that the cars are not becoming more vulnerable as they get older.
A possible link to weak 12V batteries?
Without baseline rates of 12V battery issues in all Nissan Leafs (irrespective of whether they had suffered brake problems or not), it is impossible to draw any firm conclusions about whether a weak 12V battery will make the Leaf more likely to experience brake issues. The brakes are electrically powered but there is a backup capacitor that takes over in the case of sudden failure of the main 12V supply to the EDIB. Nevertheless, the potential for a link between probability of a brake fault and low 12V battery voltage is possible, especially at initial startup. This possibility is too important to ignore while we search for more information. In the meantime we strongly recommend that owners take note of any warnings and replace the 12V battery if there are any signs of it having lost significant capacity. It is very important that any warning lights remaining on after the car is started are not ignored. It seems less likely that a weak 12V battery could trigger a brake fault once the car is operating because the 12V system is from then on supported by the main traction battery, although further testing is required to confirm this.
Recommended responses at the time of a brake fault
As we saw in the overseas reports, while drivers experienced increased pedal travel there were significant differences in the reported force required (up to “extreme” pressure needed) and only some reported the shuddering with the brakes suddenly grabbing. While we earlier believed that the best advice was to push as hard as was required to stop and not pump the brakes, both which are mentioned in the Nissan Leaf owner handbook and referenced by the NZTA, there are indications that in some cases it may be more appropriate to release the pedal and reapply if effective action is not being achieved. We have written to NZTA for guidance on this issue but have not yet received a response.
NZTA’s risk assessment and importance of the surprise factor
We agree with the NZTA findings (see the Appendix for full details) that under the irregular pedal condition as observed during NZTA tests, that we have called “assist mode” as advised by Nissan, that adequate braking was seen. However, in our view, this is a subset of cases and other observed responses requiring “very hard” or “extreme” pedal pressure have not yet been adequately characterised and are potentially more serious. The incidence of this more severe form of fault is difficult to quantify, noting that the incidence of this more severe form of fault mode is difficult to quantify.
More fundamentally, the trial takes no account of the “surprise factor” that may slow the driver’s response. This is illustrated in the following graphic, which is based on the Queensland Government data for an average family car. The ‘surprise and decision’ delay could be critical but fully replicated trials are needed before the stopping distance under EDIB fault conditions are known. Existence of two quite distinct states in the brake-assist mode (with and without full ABS functioning) further complicates these predictions.
We hope that the warnings above go some way to make drivers more aware and prepared should they encounter problems, with the primary response being to slam the brake pedal hard to the floor, although we can’t rule out that in some case releasing the pedal and then depressing it again may be required. It is realistic to assume that many affected drivers will either not be aware of what to do, or taken several valuable seconds to discover what they need to do when confronted with an emergency situation.
While we await NZTA’s deliberation of the risk and whether or not a firmware fix is made available from Nissan, Flip the Fleet will dedicate its efforts to awareness raising to reduce the surprise and decision delay as much as possible.
Ongoing research and monitoring
We have not yet called for logbook reports from overseas EV communities, but will begin that in Japan shortly because most of New Zealand’s Leafs come from there. In view of the large number of Leafs in other countries, it seems likely that more cases will be reported from overseas which may help us pinpoint causes or warnings of potential problems. New cases will be reported here as they are received and any new insights will be advised as soon as possible.
If you have any more relevant information, hypotheses, questions or criticisms of the material presented here, please (i) share them publicly via the blog below, or (ii) email us at brakes@flipthefleet.org, or (iii) complete a logbook report at www.flipthefleet.org/leaf-brakes-logbook. Citizen science is a team effort and requires professional scepticism and open debate to make the best conclusions possible. Electric vehicles are a developing technology and problems are inevitable despite the best intentions of the designers and manufacturers. The owners and operators are key experts, so clubbing together to gather systematic information helps everyone.
You can also register your interest to receive future updates by filling in the log book even if you have no brake fault to report. We also appreciate receiving screenshots of the ECU and DTCs screens in the LeafSpy Pro ‘Service menus’ irrespective of whether you have experienced a brake problem – the reports help us piece together a statistical picture of firmware deployments and earlier problems before you owned the vehicle. Instructions for finding the ECU and DTC screens can be found at www.flipthefleet.org/leaf-brakes-firmware-check/ and www.flipthefleet.org/leafs-dtc-check/. Having information on the firmware and other fault codes from vehicles that have not had a brake fault contribute to a ‘non-treatment’ group comparison with those experiencing brake problems, so please send in those screenshots!
Will firmware upgrades reduce risk?
Near the beginning of this investigation, we discovered the first case of brake firmware ‘C’ installed on a car from Japan with an unexpected EDIB firmware for that year (e.g. 3NG9C was installed on a car that would normally have 3NGxA). Since then we have found several more examples of this update being completed in Japan. We can find no public announcement of the existence of firmware ‘C’ on the 3Nxxx series or even a general description of what it does or why it is being applied to some Nissan Leafs in Japan. In Japan, we understand that Nissan’s current solution to anyone reporting concerns with their brakes on a MY2014/2015 car is to complete a firmware update to the relevant ‘C’ version.
Nissan have not responded to our repeated questions about whether a firmware upgrade exists to reduce the risk of EDIB faults, and whether it will be made available in New Zealand. In the meantime, it seems that the only recourse for worried owners is to purchase an “unofficial” firmware C upgrade. Flip the Fleet does not endorse any business in its work and certainly believes that it would be far preferable for owners to be able to have the software made available through the official dealer network. The sooner that NZTA make a deliberation about the safety of the vehicles and Nissan clarifies the existence and suitability of any upgrade, the better for everyone.
What happens next?
The fragmentary data available so far suggests that between 6 and 21 similar EDIB faults will occur in New Zealand over the next year in 2013-2016 Leafs carrying the original ‘A’ or ‘B’ firmware, assuming that increasing numbers of people buy them at the escalating rate observed over the past two years. This seems like a significant number to us and well worth minimising if remedies can be found.
The most critical and urgent need is to understand the causes and remedies for the second state of the EDIB fault where we surmise that the ABS is no longer helping the driver to stop. This fault greatly extends the stopping distance possible when just using force on the brake pedal. We have insufficient trials or background information to fully understand what causes this secondary fault state, but one of our test cars exhibited both states, overa short period of time, after the EDIB fault was triggered experimentally. The existence of two states is consistent with some of the EDIB fault case histories indicating very little braking power (state two), while others exhibited impaired but still considerable braking power (state one). We urge NZTA and Nissan to investigate further with formal and well-replicated experiments in controlled conditions. It seems logical to seek a remedy to eliminate the main EDIB fault altogether if firmware is available to fix that first step, but it would also provide added security if reliable initiation of the secondary ABS assist mode can be achieved as well.
Scores of requests for follow-up information to Flip the Fleet and discussion on EV Facebook support groups over the past weeks underscore owners’ concerns about what they are facing. If New Zealand is to base a large part of its uptake of EVs on purchases of second-hand imports, purchasers need to have confidence that they are safe and that any necessary repairs are available.
Despite the large number of additional brake faults cases now reported, we find ourselves in much the same uncertainty as two months ago when first alerted about the growing number of EDIB faults. We do have some indications that suggest that Nissan’s latest ‘C’ brake firmware updates may resolve the EDIB fault discussed, but this has not yet been confirmed either by our own testing/analysis, or comments from Nissan (global), Nissan NZ or NZTA. We have also not have confirmation from Nissan NZ whether or not these brake updates will be made available to all NZ Leaf owners through their dealer network. Most of all, we have had no declaration by Nissan or NZTA that the vehicles carrying firmware A or B are safe to drive in New Zealand conditions. The informal investigations reported here highlight the potential risk of a brake fault only. Nothing we have found or reported here confirms that significant risk occurs, nor that it doesn’t occur – that judgement is for NZTA alone to make.
Our recommendations:
Become informed
The new information received from the logbooks leads us to add five new FAQs to the original list found here. We urge all Leaf drivers to consult the updated information to be as prepared as possible.
Know what to do
We believe that in most situations the best action will be to slam the brake pedal right to the floor and exert as much pressure as you can muster on the pedal; however, it has been reported, that in rare cases not related to EDIB faults, releasing the pedal and then depressing it again was required to re-engage the brake. We have asked NZTA for their recommendation which we will post here as soon as received.
Preventative actions
Many of the more minor brake faults reported here can probably be fixed by service agents, so regular servicing is recommended. Faults in the firmware are different altogether – they may come out of the blue without any warning signs, and we do not know if having experienced a fault once is an indication that it is more likely to happen again. We recommend that you scan and store a record of your ECU and DTC screens using LeafSpy Pro and clear any of the past codes present. It is useful to clear the codes so that you can better diagnose any new events.
The potential link to a weak 12V battery is unproven, but it’s best practice anyway to check your 12V battery regularly and make sure it is maintained well.
After an event
If you experience any of the braking faults,
- Take a copy of the ECU and DTC screens using LeafSpy Pro and store them as a record. Do not clear the DTC screen in the meantime because Nissan and NZTA may need it as a record for their own investigation.
- Fill in a brake logbook report at www.flipthefleet.org/leaf-brakes-logbook and if possible attach the ECU and DTC scan screenshots.
- Get it checked out and by a certified Nissan service agent ASAP; if you do not have access to a certified Nissan service agent, immediately take your car to a garage specialising in EV repairs for a check (but in that case, make sure you also notify Nissan New Zealand of the fault). Correspondence from NZTA suggested that Nissan would provide this service pro bono, but several uncertainties remain (see email exchange on 12 December 2018 by clicking here).
- Faults relating to hardware issues should be repaired immediately. Many of the smaller faults reported in the ‘Other faults’ category in this report may be fixed by recalibration of the brake pedal stroke.
- Notify NZTA of the fault and repairs done by your service agent so they can monitor the risks
- Stay on the case! If the fault recurs, record, notify and request help again.
Please add your insights, criticisms and questions to the blog below so that we can all work through this issue together.
Daniel Myall, Henrik Moller, Dima Ivanov, Walter Larason, Joe Barnett, Donald Love and Mark Nixon
17 December 2018.
Appendices
1. Brake System Components
2. Nissan’s Response
3. NZTA’s response and tests
4. Overseas reports
5. Flip the Fleet simulations of EDIB faults
Appendix 1: Brake System Components
The Leaf USA Service Manuals have been used to develop the following sections. For copyright reasons we will not display the drawings. The BR (Brake System) and BRC (Brake Control System) manuals can be found online for those who want further detail.
Electrically-driven Intelligent Brake Unit (EDIB)
- Named e-ACT Electrically-driven Intelligent Brake Control Unit in our earlier report
- EDIB in NZTA report (an subsequently in this updated version of our report)
- Integrates the control module, master cylinder, and brake booster, and it controls the fluid pressure that is sent to the “ABS actuator and electric unit (control unit)”.
Brake Booster and Master Cylinder
- Part of the EDIB
- Pedal input is on the left of the photo above
- Contains a motor and generates boost force according to the amount that the brake pedal is depressed and the amount of cooperative regenerative brake control
- Uses the boost force to generate fluid pressure in the master cylinder on the right of the photo
ABS Actuator and Electric Unit (Control Unit)
- Title is taken from the service manual
- Located on the left firewall behind the glovebox
- Hydraulically in line between the two master cylinder outputs (one feeds front RH, rear LH; the other front LH, rear RH) and the brake calipers
- Contains a pump used for assist functions
- There are multiple valves to manage pressure to each brake caliper independently
- Takes input from other control modules for Vehicle Dynamic Control (VDC) function, Traction Control System (TCS) function, Anti-Lock Braking System (ABS) function, Electronic Brake Force Distribution (EBD) function, Brake limited slip differential (BLSD) function and brake assist function
System Connections
- The EDIB has two power supply lines (main and backup)
- The EDIB communicates with the “ABS actuator and electric unit (control unit)” over two communication lines
Appendix 2: Nissan’s response
We have had no acknowledgement from Nissan that a fault with the braking system of Nissan Leafs (2013-2016) in New Zealand exists, and therefore we have no answer to the fundamental question we asked: Is the car safe to drive? Nor has there been any answer to our questions about what the brake Firmware C upgrade does and whether it will remedy the faults occurring here.
In an article on Stuff and Noted, Nissan is quoted as “Manley [for Nissan] urged any concerned Leaf owner to take it to a reputable dealer for a look-over. “They’ll check it out for you. It doesn’t matter whether its a Leaf or a Rolls Royce.” In any case, before forwarding this advice to you, we decided to get some certainty around a few questions. We asked the following four questions by email to Nissan on the 28th of November 2018:
- Will all authorised Nissan dealerships in New Zealand agree to inspect imported Nissan Leafs manufactured in the UK or Japan?
- Do all authorised Nissan dealerships in New Zealand have access to full Diagnostic Trouble Code (DTC) information to effectively interpret any DTCs that may be found in imported Nissan Leafs manufactured in the UK or Japan during an inspection?
- Do all authorised Nissan dealerships in New Zealand have the tools, diagnostic equipment and appropriate software licenses to effectively work on imported Nissan Leafs manufactured in the UK or Japan?
- Do all authorised Nissan dealerships in New Zealand employ technical personnel that are fully trained and competent at assessing Diagnostic Trouble Codes that may be found in imported Nissan Leafs manufactured in the UK or Japan, and subsequently, carrying out the required servicing?
The response we received read “Our advice is for any Nissan owner who has any concerns as to the operation of their vehicle to take it to a Nissan dealership for inspection by a certified Nissan technician.” This partial response did not clarify the extent of service being offered. We then followed up with these four questions again on the same day, and for a final third time on the 30th of November, without response from Nissan. However, NZTA stated (5th of December) that they “can confirm that Nissan will fully inspect any Leaf vehicles presented to them for faults”, noting that this inspection is believed to be at a cost to the owner.
Nissan New Zealand’s refusal to answer these four questions leaves us unsure whether they have the ability or willingness to service imported Nissan Leafs.
More fundamentally, we do not understand how a visit to a dealer can advise on the probability of a fault in the braking system that appears out of the blue, like the EDIB fault that triggered our inquiry. If Nissan do not acknowledge the existence of the fault, nor a remedy (should one exist), how can a dealer provide meaningful advice or assistance? If you experience a EDIB fault, the Diagnostic Trouble Codes will indeed show that it occurred, but no one can meaningfully advise in advance if such an event will be likely to happen. Nor do we know if the fault has occurred in your car once, whether it is more likely to happen again unless upgraded firmware is made available and has been designed to fix the fault.
Some of the other faults we have observed can perhaps be identified and risks mitigated.
John Manley (General Manager of Nissan New Zealand) is reported to have stated that Nissan knew of only one Nissan Leaf being presented to a dealer with the suspected braking issue, which “turned out it was a parts issue,” and “The driver just drove off, he didn’t want to take it any further.” This is inconsistent with three of the Logbook entries reporting that the owners complained to Nissan, maybe highlighting the lack of an appropriately monitored support channel.
Appendix 3: NZTA’s response
A full list of our correspondence with NZTA from 14 November 2018 to 14 December 2018 (65 pages) can be downloaded as a PDF file by clicking here.
We have had no formal acknowledgement from NZTA that a fault with the braking system of Nissan Leafs (2013-2016) in New Zealand exists, and therefore we have no answer to the fundamental question we asked: Is the car safe to drive? Nor has there been any answer from NZTA to our questions about what the brake Firmware C upgrade does and whether it will remedy the faults occurring here.
Nevertheless, the New Zealand Transport Agency (NZTA) has investigated, including a trial of a Nissan Leaf on rollers to measure braking resistance when the brakes are experiencing an EDIB fault. You can find their official response to Flip The Fleet’s enquiry by clicking here, and you can download the referenced “Attachment 1” by clicking here.
While it was encouraging to see a test being carried out, and the results aligning with two of the fault symptoms we observed (pedal action irregular, similar to ABS pulsing only at a slower rate, and more pedal effort required), we felt that NZTA’s response left a lot of questions unanswered. We have therefore followed up with an additional request for clarification, which you can read by clicking here.
Flip the Fleet is not equipped or mandated to make a formal assessment of the risks posed by the brake problems recorded in this study. That is the job of NZTA only. We are also extremely grateful that NZTA conducted an independent trial. Therefore we proffer the following concerns about interpretation of the trial conducted by NZTA (and their response so far) in a spirit of professional scepticism as citizen scientists:
- The trial described is unreplicated – a single Leaf was used and a single test in each case and for an defined test speed (possibly 2.7 km/h based on BM12200 specifications)
- Our braking tests where “assist mode” is active show significant variations in braking force with vehicle speed (ABS seems to be constantly making decisions), suggesting a single speed test is only a partial indication of braking effectiveness. There may be a lack of evidence to justify a claim of braking efficiency at other speeds due to dynamic changes in braking when under “assist mode”.
- There is no indication of whether the regenerative braking by the motor was engaged or not during the trial
- The DTC reported after the NZTA trial (U1000, P3195) are different from the ones reported for the real brake faults reported (U1000 and U110D)
- The use of a roller brake machine is a totally artificial situation that does not replicate the situation faced by a driver experiencing the faults in real road conditions
- The trial was conducted on a COF B testing machine which we understand is used for heavy vehicle testing. Was this machine calibrated to give reliable measure of braking force in a Gen 1.2 Leaf which has a kerb weight of 1.5 tonnes?
- The report does not record whether noises occurred during the NZTA trial. Were sounds present, and if not, does this indicate that the trial did not accurately reproduce the expected stopping effectiveness in real life?
- Drivers who had experienced a real brake fault event were not included in the NZTA simulation to gauge whether or not the test felt or sounded like the real event
- Flip the Fleet’s own experiences of simulated brake assist mode indicate multiple states of brake impairment (some demonstrated much more effective braking than others). We do not fully understand what causes this variation, but we believe it is likely the more aggressive ABS “assist mode” state was active during the one NZTA trial.
- There appears to be no inclusion of the “surprise factor” expected when brake fault occurs. Significant delay in activating the brake assist mode, or inadequate engagement of the brake assist mode may occur if the driver does not fully depress the brake or not apply sufficient and continuous force – a diagram of the potential importance of the delay because of surprise is provided in the main report body above.
- There was no clear declaration of NZTA’s overall conclusion, so we still do not know if they consider the cars safe to drive.
By completing a standard WOF test, with the EDIB controller disabled, NZTA have concluded that the non EDIB boosted braking meets minimum standards to pass a WOF test. This might not be a justified conclusion if the “assist mode” provides variable braking force at different speeds or stages of the stopping cycle but more importantly less likely to be valid under the more impaired state observed during some of our tests.
What NZTA testing does not consider, is the manner in which the vehicle is being controlled. Under staged conditions, where the vehicle is operating on a rolling road, with the operator fully aware of what is required, the brake “assist mode” may be suitable. In a situation where a system fails unexpectedly, completely changing the characteristics of the most important safety related function on the vehicle, it can’t be assumed that the operator will be suitably alerted to impending required response.
Everybody accepts that mechanical and electrical components occasionally fail, however, when there are multiple documented occurrences, which require significantly increased pedal pressure and this after the pedal has travelled over twice it’s normal travel, this is not just a random fault. For any meaningful results to be gained from testing, a more complex test needs to be employed. One simple benchmark against minimum standards under different conditions is not acceptable in our view.
The NZTA concluded that “If a Nissan Leaf has a CAN Bus malfunction for whatever reason and loses power to the EDIB the brakes are still more than adequate to bring the vehicle to a stop and still meets in-service WoF requirements”. We agree this may apply for some faults but implies the statement covers all fault states. It is unfortunate that the other car state was not found during NZTA testing as the above conclusion is not supported by all the driver reports submitted to Flip The Fleet or our own testing. More fundamentally, benchmarking against a single minimum requirement of WoF is in our view a very limited appraisal of risk that disregards many of the additional conditions itemised above and also the frequency with which the fault occurs.
An important consideration is that the Leafs often have fairly aggressive brakes and drivers are careful to only apply the minimum pressure needed otherwise strong braking can occur (“grabby brakes”). This gentle application means under a fault condition there can be a significant time delay as the increased pedal travel is explored to find where braking occurs, resulting in greater distance being travelled before brakes begin to operate.
We’ll keep you posted on any further details as they arrive from NZTA.
Appendix 4: Overseas Reports
In our original blog we mentioned overseas forum posts. The SpeakEV forum has a UK focus but also other contributors. The information of interest is spread across multiple posts and a detailed analysis has not been done. An index with notes and in some cases verbatim copy is available here.
We also referenced the NHTSA (USA) database of complaints and we have extracted the records tagged as “Service Brake” into a PDF available here. Note there is only one mention of fault codes and firmware versions are usually not stated. A total of 7 cases specifically mentioned that a firmware update had been done (we assume to version B) and a subsequent fault occurred.
Appendix 5: Flip the Fleet simulations of EDIB faults
Simulation 1: 10 November 2018
Braking distance for a 2014 Leaf was measured using accelerometer and tape measure, starting with “normal” braking conditions then artificially induced brake “assist mode”.
Measurements of stopping distance are challenging to perform accurately. Based on tape measure and accelerometer results stopping distances increased by around 50% under EDIB simulated faults, going from shorter than the “average family car” in the Queensland data to slightly longer under fault conditions.
The following graphic was based on data from the accelerometer to highlight increased time and hence distance to stop. This is timed from when braking starts and any driver reaction time would be additional.
These results are not intended as precision measurements but rather an indication of the different mode results. The two drivers concluded:
- Not total brake failure, though it feels like it at first
- Limited trials suggest stopping distance at around 44% more at 100 km/h (reaction time issues additional)
- Replicated and more controlled trials needed by certified personnel in safe conditions
- “Surprise” factor is expected to significantly increase stopping time and distance.
Simulation 2: 24 November 2018
The same 2014 Leaf used on 10 November had the EDIB disabled via software command for Flip The Fleet. Drivers 1 and 2 were experiencing this fault condition for the first time. Drivers 3 and 4 had previous brake fault and were asked to drive the car and assess whether the symptoms were similar to their earlier experience. Commentaries were recorded on video, which also captured the speedometer display for all but Driver 2, and used to produce the summaries below.
Driver 1 – Flip The Fleet
- Initial pressing of pedal with the car stationary generated graunching noises and juddering of the pedal
- Attempts to stop from 50 km/h had a lot of pedal travel with braking only starting when high force applied
- Noted that there was minimal juddering and pedal smooth
- Subsequent stops exhibited similar symptoms needing high brake pedal force, estimated as “at least 50 kg”, being required to stop
- Noted that a lot of pedal travel gave no braking action and feeling of no brakes being available
- Later checks on the same car disabling the ABS produced similar results, concluded that the ABS assist mode which should be active during an EDIB fault was not functioning for these tests
A video recording of these tests was analysed to derive the speed from the dashboard display vs time (using frame count on video) to produce the following sample plot of brake action. Note that the ABS was not deliberately disabled during this test and dashboard speed is about 10% higher than actual (i.e. stopping from 30 km/h actual even longer):
Driver 2 – Flip The Fleet
- The car remaining powered on from the first event but some minutes had passed
- When braking from 50 km/h the pedal travel was significant before braking started but only moderate force was required and the car exhibited more juddering, suggesting ABS assist was now active
- These tests included a load cell to confirm pedal force and around 15 kg was quite adequate to provide firm braking (with juddering)
- Stopping performance much more effective than for Driver 1 tests
- Note the amount of pedal travel required in these pictures
These tests are only intended as observations, not as a detailed scientific test.
For reference, the following are earlier photos of normal braking in another 2014 Leaf achieving around 8m/s2 deceleration with 9.5 kg pedal force (note camera angle slightly different):
The car remained in this mode, which we believe is ABS assist, for the following tests.
Driver 3 – Previous Experience of Fault
- There was much less brake resistance in original fault during initial brake attempt
- Considerably more stopping power during the simulated test than he remembered during the actual event in his car
- Sounds were similar, at least when trying to drive it after initial fault, with two noises (other source off to the left)
- Subsequent movement of the car at lower speed felt similar [juddering] Recovery truck driver got similar noise and juddering also repeated later
- Feel could stop this time if pressing harder
- Warnings look similar
Driver 4 – Previous Experience of Fault
- Had graunchy sound same as before but couldn’t stop during original fault
- During fault pressed as hard as could and wasn’t stopping
- This simulation is different to original fault – felt this one would work
Just a general query:
Will this affect our insurance? Now that we ‘know’ that there might be a problem, are we still covered in case of an accident?
Hi Trevor, this is a brilliant question! We haven’t been in contact with the insurance industry, nor have they been in touch with Flip The Fleet, so we don’t have an answer for you right now. But perhaps it’s a question that should be asked.
I plugged a Comma.ai Panda into my 2016 Leaf’s OBDII port and BAM car’s HV system immediately faulted and power braking was lost. I towed it to a dealership to reset the system, and is now working nominally. This was in California.
This has just happened to my 2016 leaf in the UK and it was terrifying! Luckily no accident but could have been so bad.
Does anyone have any chassis numbers or anything to check this? I’ve opened a case Nissan but not much coverage in the UK about it.