Back in October 2015, Nissan North America began a voluntary service campaign to address a fault with certain model-year Nissan LEAFs in which the electronic brake booster system could fail to operate properly in cold weather, requiring more pedal effort to stop the car and thus increase overall stopping distance.
Yesterday, the Japanese automaker turned that service campaign into a full-blown recall affecting some 47,000 Nissan LEAF electric cars in North America. While there appears to be no report of accident or injury directly related to this fault, Nissan says that one hundred percent of all Nissan LEAFs made between November 19, 2012 and July 31 2015 are believed to susceptible to this particular problem under the right conditions.
According to official document submitted to NHTSA by Nissan, the fault lies with the electronic relay that controls the LEAF’s electronic brake booster system, which can freeze up in sub-zero temperatures, preventing the brake booster system from working and effectively leaving the car without power-assisted brakes.
Unlike most internal combustion engine vehicles of the past thirty years or so — which use vacuum from the engine to multiply the braking force applied to the wheels when you put your foot on the brake pedal — electric and hybrid cars use a small electrically-operated pump (and a vacuum reservoir) to provide the same functionality. To keep the vacuum pressure at the right level, the pump switches on and off as required while the car is in use to ensure that there’s always power-assisted braking when required.
As detailed by Nissan, when the electronic relay responsible for switching that pump on and off freezes up, the car can’t produce the required vacuum assistance and thus while the brake pedal still operates, the force applied to the wheels is far less than it would be under normal operating conditions.
Nissan says the fault only occurs when the car is parked in extremely cold temperatures for a prolonged period of time, which means that the majority of customers in warmer parts of the U.S. and Canada are unlikely to experience the problem. However, if the problem does present itself, the brake warning lamp should illuminate to warn the driver that there’s a problem.
The fix — which Nissan said should take less than one hour to complete — involves reprogramming of the e-ACT (Electrically-driven Intelligent Brake Control Unit) of affected cars with new software.
While the problem was initially disclosed in October last year as a service campaign issue — which Nissan notified NHTSA and Transport Canada about — it appears Nissan was asked by Transport Canada in February this year to reclassify the service campaign as a safety recall campaign. While only 679 Nissan LEAFs in Canada are believed to be affected by this recall, it follows that they were more susceptible to suffering the issue given Canada’s usually colder winters compared to much of the U.S., and thus the reclassification request makes total sense.
Additionally, the switch of status from a service campaign item to a voluntary recall means that under U.S. federal law, dealers cannot sell or deliver vehicles in their inventory which are covered by the recall until necessary steps have been taken to remedy the problem.
Nissan says that while it rapidly launched the original service campaign and was pleased with the more than 21,708 LEAFs which have already been presented at dealers in North America for a complementary fix, it does not believe that the issue is a safety defect. However, given the nature of the request and the considerations of colder-weather, Nissan decided to reclassify the service campaign as a safety recall in the U.S. at the same time as it was being reclassified in Canada.
Those who have already had their cars reprogrammed at their local Nissan dealership are not covered by this recall as it has effectively already been carried out under the previous service classification. Those who have not yet had their cars reprogrammed should already have been contacted by Nissan North America, detailing the service campaign and asking them to make an appointment with their local dealership for remedial work.
Nissan says it will contact all owners with outstanding recalls again within sixty days via post.
As with all recalls, the cost of the recall will be carried out under warranty at no cost to the owner.
Have you experienced this brake problem with your Nissan LEAF? Have you already sent your car in for the required remedial work?
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