This is a quick update on our investigation of EDIB (brake) faults in Nissan Leafs manufactured between November 2012 and February 2016 (the “Affected Nissan Leafs”, previously documented via our original post from November and a subsequent update in December). To find out the month your Leaf was manufactured, you can look your car’s registration number up on www.carjam.co.nz – on the first line “year”, the year and month of manufacture is often listed in brackets, like “(2016-03)”. If you can’t find your car on CarJam, you can also try Japan-Partner.
We’ve drafted our third update that goes into much more detail, and presents the new findings from our investigation, but final analysis and checking by our peer review panel need to be completed before it is published in a few weeks. We wanted to reach out to you sooner.
Nissan recently confirmed that they have known about the issue of EDIB faults in Nissan Leafs related to use of OBD2 devices for a long time (Nissan material we’ve been given is dated June 2015), and Nissan has posted advice on their Japanese Recall/Service Campaign Information web site in December 2015 (Google translation here or here) that installing/using OBD2 “communication devices” will trigger brake faults, amongst other system issues. Therefore, you may wish to consider Nissan advice “not to use aftermarket OBD2 devices as they cause issues with brakes and other systems”.
According to this information, the new explanation for EDIB faults now provided by Nissan is that the EDIB faults are triggered at the time of the Leaf being in READY OFF state (i.e., turned off) if an OBD2 device is left inserted. Note that we were provided with this information after Nissan New Zealand was presented this summer with a Leaf in EDIB fault mode with an OBD2 device inserted – therefore unrelated to the sub-freezing explanation Nissan provided previously.
Please let us be clear – the Nissan Leaf EDIB faults we are investigating appear to be a design fault in the brake system’s firmware installed by Nissan at time of manufacture. Using OBD2 devices does not in itself appear to be the root cause of the faults – we have been sent several videos of EDIB faults occurring in Leafs without any OBD2 device being connected for the vehicle’s recent history. But after receiving details of further EDIB faults where OBD2 devices were connected, we now have sufficient statistical grounds to believe that having a permanently-connected OBD2 device in affected Nissan Leafs significantly increases the chances of an EDIB fault occurring. Examples of these are the “Bluetooth/WiFi dongles” used with LeafSpy Pro for continuous DropBox logging, EV Black Box, FleetCarma devices, OVMS, or perhaps, other telematics devices such as used for fleet management purposes, insurance companies, car alarms or remote car control systems which are permanently connected to the Leaf’s OBD2 port. It may be possible to modify the behaviour of OBD2 devices to reduce risks, but no scientific evidence is available to confirm a reduction in risk. As far as steps taken, we have already spoken with the teams behind LeafSpy, FleetCarma and OVMS, all of whom are looking into our findings already. Additionally, the EV Black Box has been reconfigured to send requests only when the Leaf is turned on.
While our finding above relates to permanently-connected devices, we have no verified or statistically-significant information to indicate that periodic use of OBD2 devices (e.g. connecting a dongle for a few minutes to scan your car once a month or so) increases the chances of brake faults. We also have no information to suggest that use of OBD2 devices in “non-affected Nissan Leafs” increases the risks of any faults.
And lastly, if you drive an affected Nissan Leaf, we recommend that you check your 12V battery at a professional battery shop – and replace it if advised. Additionally, please pay attention to any warning lights on your dash and avoid driving your car if any warning lights are lit up. Make a habit of this check!
We have advised the New Zealand Transport Agency of the results of our analysis and stand ready to work with them and any other affected parties to reduce future risk.
We’ll next be in touch when our third update is published, and for now, we look forward to your comments and questions.
The team at Flip The Fleet.