Honda Motor (HMC) vehicles will undergo an engineering analysis by the National Highway Traffic Safety Administration due to complaints regarding the Auto Idle Stop feature on some models.

The engineering analysis, which involves around 2.2 million Honda vehicles, was opened by the agency on Wednesday. The complaints allege that the engine fails to restart on its own from a complete stop with the Auto Start/Stop function engaged, with some incidents requiting a "jump start," the agency said.

Complaints related to the engine restart issue were first received by the agency in June 2022. Honda in January 2023 released a service bulletin featuring a two-stage countermeasure to remedy the issue. The agency's Office of Defects Investigation continued to receive complaints of the failure to restart, even with the countermeasures already implemented.

The agency said it opened the engineering analysis to consider the potential safety defects and gather additional data on the company's service campaign. The agency also expanded the scope to include all vehicles that are substantially similar to the ones covered by the campaign.

There have been 1,384 complaints related to the issue recorded by the agency, with four resulting in crashes or fires, the agency said.

Honda did not immediately reply to a request for comment from MT Newswires.