Toyota investigation of alleged ‘runaway’ Prius

March 17, 2010

On Monday, March 15, Toyota discussed preliminary findings from its technical field examination of an alleged “runaway” Prius. “Based on these preliminary findings, it would seem that the account of this incident by the driver is inconsistent with the technical investigation,” noted TMS spokesman Mike Michels.

The investigation, conducted by a team of Toyota engineers, tested all of the principal components related to this incident. It concluded that they were all functioning normally, including a form of brake override that is an inherent part of the hybrid system. NHTSA investigators were present during Toyota’s examination and are conducting their own investigation of the vehicle.
 
Among other things, Toyota concluded that:

• The accelerator pedal was working normally with no mechanical binding or friction. Please keep in mind that the Prius is not subject to a recall for sticking accelerator pedals and the Prius component is made by a different supplier than the one recalled.
• The push-button power switch worked normally and shut the vehicle off when depressed for three seconds as the 911 operator advised driver to do.
• There were no diagnostic trouble codes found in the power management computer, nor was the dashboard malfunction indicator light activated.
• The hybrid self-diagnostic system showed evidence of numerous, rapidly repeated on-and-off applications of both the accelerator and the brake pedals. Bob Waltz, TMS vice president of Product Quality and Service Support, said at the briefing that the front brakes showed severe wear and damage from overheating, which he noted would be consistent with repeated light use of the brakes.
• During testing, the brakes were purposely abused by continuous light application in order to overheat them. The vehicle could be safely stopped by means of the brake pedal, even when overheated. “The brakes still should have stopped the car,” noted Waltz.

 You can get more information on Toyota’s findings here.

Tags:  Toyota