SAN DIEGO, CA - Toyota said Monday, March 15, that its preliminary test results on a 2008 Prius, which was allegedly involved in an unintended-acceleration episode last week near San Diego, were inconsistent with the driver's account.
Toyota engineers on March 10 and 11 performed a technical field examination and testing on the car. "While a final report is not yet complete, there are strong indications that the driver's account of the event is inconsistent with the findings of the preliminary analysis," the company said.
Toyota said tests indicated that the driver repeatedly pressed the brake pedal and accelerator -- a conclusion that's at odds with the driver's account that he applied heavy pressure on the brakes while the car accelerated out of control on its own.
"We believe the vehicle was being driven with the front brakes lightly applied," Bob Waltz, Toyota's U.S. vice president for product quality and service support, said on Monday, according to a Wall Street Journal account of the press conference in San Diego.
James Sikes called 911 on March 8 while driving on a California freeway to report his Prius had sped up to more than 90 mph on its own and couldn't be stopped. Eventually, a California Highway Patrol officer pulled alongside Sikes' car and advised him to apply both the brakes and the emergency brake and to turn off the engine. Eventually, the car came to a stop. Sikes was uninjured.
Toyota said company engineers employed data download/analysis, static and dynamic testing as well as thorough inspections of all relative components. In addition, Toyota said, company engineers retraced the reported driving route, taking into account driving time and statements from the 911 recording.
Toyota said the accelerator pedal was found to be working normally with no mechanical binding or friction. The front brakes showed severe wear and damage from overheating, but the rear brakes and parking brake were in good condition and functional.
In addition, the automaker said, a carpeted floor mat of the correct type was installed but not secured to the retention hooks. It was not found to be interfering or even touching the accelerator pedal, Toyota said. Also working normally were the push-button power switch and the shift lever. The 911 operator had advised Sikes to shift the car into Neutral and depress the power button for three seconds to turn the car off.
"There were no diagnostic trouble codes found in the power management computer, nor was the dashboard malfunction indicator light activated," Toyota said. "The hybrid self-diagnostic system did show evidence of numerous, rapidly repeated on-and-off applications of both the accelerator and the brake pedals."
The Prius braking system is designed to use both conventional hydraulic friction brakes and a regenerative braking system that switches the electric drive motors into brakes to generate electricity. The system has a self-protection function that cuts engine power if moderate brake pedal pressure is applied and the accelerator pedal is depressed more than approximately 50 percent. "This function, which is intended to protect the system from overload and possible damage, was found to be functioning normally during the preliminary field examination," Toyota said.
Toyota engineers concluded "it would be extremely difficult for the Prius to be driven at a continuous high speed with more than light brake-pedal pressure, and that the assertion that the vehicle could not be stopped with the brakes is fundamentally inconsistent with basic vehicle design and the investigation observations."
Toyota suggested that Sikes' account of the incident draw further examination.
NHTSA investigators, who were present during Toyota's testing, are conducting their own examination. The NHTSA said on Monday that it couldn't yet "find anything to explain" Sikes' account of the incident. Sikes' attorney, John Gomez, said he would offer no further comment until the NHTSA had completed its investigation.
Meanwhile, California Highway Patrol spokesman Brian Pennings told the Wall Street Journal that its officer's observations about the incident aren't consistent with all of Toyota's conclusions. The CHP will release its own report.
Originally posted on Green Fleet Magazine