U.S. Probes Honda Pilots that Brake Without Warning

The U.S. has opened an investigation into 185 complaints that 2005 model Honda Pilot crossover vehicles may go into an emergency braking mode without warning.

Honda Motor Co. says the cause may be faulty yaw rate sensors that send incorrect data to the vehicle stability control system.

The control module monitors brake pressure, wheel speed, steering wheel angle, yaw rate and acceleration. The system integrates the operation of the vehicle's antilock brakes, traction control, stability control and emergency brake assist.

One of the module's functions is to reduce stopping distance during emergency braking by boosting brake pressure when it detects a panic stop. The probe launched by the National Highway Traffic Safety Administration focuses on why the system falsely detects panic braking.

The agency also notes that the system is supposed to detect a yaw rate sensor failure and switch in less than one second to a failsafe mode that disables all electronic assist functions.

The Pilot's stability assist system modulates the brakes on a wheel-by-wheel basis if it detects side slip. Some owners of 2005 Pilots have reported difficulty steering when their vehicles brake spontaneously. The agency speculates that those drivers may be feeling the system's attempt to correct a nonexistent skid by applying braking force more strongly to one side or corner of the vehicle.