Honda is recalling 635,808 vehicles in the United States because of a software defect that could cause power steering assistance to shut off, making vehicles harder to control and increasing the risk of a crash.

The recall affects 383,110 Honda Pilot SUVs from the 2023 through 2025 model years, 177,100 Acura MDX SUVs from the 2022 through 2024 model years, and 75,598 Acura TLX sedans from the 2021 through 2025 model years, according to a filing with the National Highway Traffic Safety Administration.

The problem involves improperly configured electronic power steering software developed by supplier Robert Bosch Automotive Steering LLC. An error in a calculation associated with the Driver Attention Monitor system can cause the steering system to enter a failsafe mode under certain driving conditions.

When the defect occurs, power steering assistance shuts off and warning lights appear on the instrument panel. Drivers can still steer their vehicles, but must apply greater force, potentially making them more difficult to control.

Honda reported one injury and 146 warranty claims related to the issue as of October 22. The company said it had received no reports of deaths connected to the defect.

Honda first received a report of the problem in November 2021. After its supplier identified the failure in August 2025, the automaker reproduced the issue in December. Honda later confirmed that it could occur under certain conditions while a vehicle was traveling straight and determined on October 22, 2026, that the defect presented a safety risk.

Affected owners will be instructed to take their vehicles to an authorized Honda or Acura dealership, where technicians will reprogram the electronic power steering control unit with updated software. Honda plans to begin mailing recall notification letters on December 14.