Brake Control Module Firmware Update – AZE0-2xxxxx Leaf

The Nissan Leaf features an ‘electrically-driven intelligent brake control module’. Simply put, this is an electrically-assisted brake master cylinder rather than a vacuum-assisted brake master cylinder as found on a traditional car with an internal combustion engine.

The Leaf’s brake ‘booster’ features it’s own integral control unit which interacts with other control units in the vehicle. It has the ability to command light braking requirements to be performed through regenerative braking using the traction motor only or by a combination of this and the hydraulic brakes.

We are starting to see cases on the AZE0-2 (2016-2017 Model Year) LEAF developing an intermittent fault with their Electric Driven Intelligent Brake (EDIB) system which in a small but significant number of cases had lead to the electronic system temporarily becoming completely unresponsive. In this situation there is no braking force whatsoever within the first 3/4 of the brake pedal travel. Of course, this can be highly frightening and dangerous as the driver may not instinctively know in this situation to press the pedal further all the way to the floor.

Nissan has released several firmware updates for this braking system in the years since its production, yet there has never been any acknowledgement of there being a problem. Unfortunately, after years of monitoring and analysis of a large number of cases, we don’t have confidence that any of Nissan’s firmware updates have fixed the issue. Instead we believe that the issue is hardware related. However, the latest update does seem to result in improved brake feel and performance so we do still consider this as a worthwhile upgrade to be offered alongside normal servicing (aka brake fluid check/change which is probably the single most important service item on these cars).

We have spent considerable time and effort trying to get to the bottom of this issue, but our results so far have not been conclusive. We hope that in the future we’ll be  able to offer a highly cost-effective repair, but we are not there yet. Surprisingly, in 2019 Nissan released a brand new replacement EDIB variant for the AZE0-2 LEAF and in the cases we’ve encountered, replacement with one of these units has resolved the issue. Keeping in mind that AZE0-2 EDIBs did not tend to give any issues when the cars were newer, age and wear & tear has clearly played a factor. Whether the latest units are an improved design or just newer has not been clearly established.

We are now stocking these new replacement brake units for a fraction of the price of getting one through Nissan NZ. It is a replacement for the following superseded and discontinued original parts for AZE0-2 LEAFs: 46007-4NN0A, 46007-4NN1A, 46007-4NN2A, 46007-4NN0C, 46007-4NN1C, 46007-4NN2C. Note: That this part is only suitable for vehicles originally built for the Japanese market.

Please feel free to contact us if you would like to discuss this issue further.