Honda, Acura Vehicles Unexpectedly Stall Due to Defective Auto-Idle Stop Feature, Class Action Alleges

Honda Motor Company and its American subsidiary were hit with a proposed class action this week that alleges certain Honda Pilot, Honda Odyssey, Acura TLX and Acura MDX vehicles suffer from a defect that can cause their engines to stall when at a complete stop.

According to the 47-page complaint, the defect is related to the cars’ auto-idle stop feature, which is designed to improve fuel efficiency and, if working properly, is supposed to automatically shut off the engine when the vehicle comes to a complete stop and then restart the engine when the driver releases the brake pedal. The lawsuit argues, however, that in the vehicles at issue—the 2016-2020 Honda Pilot and 2015-2020 Honda Odyssey, Acura TLX and Acura MDX—the auto-idle stop system is defective and sometimes fails to restart the cars’ engines at a stop.

Indeed, the suit says, drivers find upon releasing the brake pedal that their vehicles have “become inoperable and immobile,” which can present significant safety problems given the affected cars are often in the middle of traffic when the issue occurs.

Safety issues aside (for now), the auto-idle stop (AIS) defect also has financial consequences, according to the lawsuit, as drivers may be required to pay for towing and ineffective repairs as they try to diagnose the issue. Per the case, “these efforts will be futile” since Honda has not come up with a fix for the problem.

The lawsuit argues that although Honda has known about the apparent defect for years, the automaker has essentially done nothing to notify customers and address the issue:

Four years and hundreds of customer complaints after first notifying authorized Service Managers and Advisors of the Defect, Defendants have failed to issue a recall, extend the warranty of the Class Vehicles, offer effective repairs and/or appropriate replacement parts, or taken any other corrective action with regard to the AIS Defect in the Class Vehicles.”

Per the case, Pilot, Odyssey, TLX and MDX drivers would not have purchased or leased their cars, or paid as much as they did, had they known about the apparent defect.

Lawsuit claims consumers purchased vehicles with “significant safety risks”

The case alleges that although safety was a consistent theme in Honda’s advertising of its vehicles, the cars may not be as safe as consumers were led to believe given the nature of the defect.

Per the case, each of the models at issue is equipped with a 3.5L engine that includes the auto-idle stop feature—which is turned on by default and must be manually turned off each time the car is restarted if the driver wants to disable it.

The lawsuit argues that since the feature is designed to function while the vehicles are in operation, any failure leaves drivers, their passengers and others at risk of an accident.

“Instead of automatically restarting the engine as expected, the Defect renders the Class Vehicles inoperable and immobile wherever the stall occurs, which frequently will be at a stoplight or stop sign, in stop-and-go traffic, at an intersection while waiting to make a left turn, or at another hazardous location where other drivers will be forced to maneuver around the stalled Class Vehicles to avoid an accident, or possibly fail to react before a collision occurs,” the complaint reads.

The plaintiff, for instance, says her 2017 Honda Pilot stalled more than once while she was in an intersection waiting to make a left turn. Each time, the woman “narrowly avoided collisions with approaching vehicles” and feared for her safety, the complaint relays.

The lawsuit says hundreds of other drivers have complained to the National Highway Traffic Safety Administration (NHTSA) about the alleged auto-idle stop problem. Per the case, a “recurring theme” in the NHTSA complaints is the “sudden danger” drivers experience when their vehicle unexpectedly stalls.

“In the eyes of the average consumer, the Class Vehicles are unsafe, and this obvious fact cannot be lost on Defendants,” the lawsuit argues.

Honda has long known about the auto-idle stop problem, lawsuit alleges

Despite these “widespread and concerning” safety issues, Honda has known about the auto-idle stop defect for years and has essentially done nothing to address it, the lawsuit argues.

According to the case, Honda issued an internal communication to its authorized service managers and advisors in 2018 in which the automaker acknowledged that customers were complaining about inoperative auto-idle stop systems in their 2018 Honda Pilot and Honda Odyssey vehicles.

In fact, the lawsuit relays, there were so many complaints submitted to the NHTSA about the apparent auto-idle stop problem that the agency opened an investigation into certain Honda Pilot models in June 2022. In the NHTSA’s initial report about the opening of the investigation, the agency noted that Honda had acknowledged in meetings that it was aware of the auto start/stop problem and indicated that other models—specifically the Honda Odyssey, Acura TLX and Acura MDX—“experience the same failure mode.”

Despite this knowledge, Honda has “continued selling defective vehicles” while attempting to conceal the existence of the auto-idle stop problem from consumers, the lawsuit alleges.

Who does the lawsuit look to cover?

The lawsuit seeks to represent anyone in the United States who purchased, leased or owns a 2016-2020 Honda Pilot, 2015-2020 Honda Odyssey, 2015-2020 Acura TLX or 2015-2020 Acura MDX.

How do I join the lawsuit?

There’s usually nothing you need to do to join or be considered part of a class action lawsuit when it’s first filed. The time for Honda and Acura drivers to take action would be if and when the lawsuit settles, at which time people covered by the settlement, who are known as class members, should receive notice of the deal and instructions on what to do next.

Keep in mind that it often takes months or even years for a lawsuit to be resolved.

In the meantime, if you want to stay in the loop on class action lawsuit news and settlement information, you can sign up for ClassAction.org’s free weekly newsletter here.