By Gina Yarbrough
SAN DIEGO–Toyota officials say they were unable to find anything mechanically wrong with the alleged “runaway Prius,” driven by a local man who claimed his vehicle sped out of control on a San Diego freeway last week.
At a news conference Monday, Toyota said the automaker’s engineers concluded two days of intensive testing of the 2008 Toyota Prius hybrid, driven by James Sikes of Jucumba. The investigation revealed that the vehicle’s gas pedal and backup safety system were working normally with no mechanical binding or friction.
Sikes was the subject of a 24 minute 911 emergency call on Monday, March 8 on Interstate 8 in San Diego. He reported that his vehicle was traveling out of control at a high rate of speed of 94 mph, and the accelerator pedal was stuck, and was unable to stop the vehicle. The emergency dispatcher instructed Sikes to shift the car into neutral and turn off the power button.
A California Highway Patrol officer intercepted the vehicle and instructed the driver to press firmly on the brakes, apply the emergency brake and turn off the car, at which time the Prius came to a safe stop.
While a final report is not yet completed, Toyota officials said there were strong indications that Sikes’ account of last week’s event on Interstate 8 is inconsistent with the findings of the preliminary analysis.
“Contrary to early reports that the patrol car physically stopped the Prius by positioning against the front bumper, the Highway Patrol has confirmed the vehicle came to a stop on its own,” said Mike Michels, vice president of communications, Toyota Motor Sales.
Toyota engineers and technicians examined and tested Sikes’ Prius last week at Toyota of El Cajon. Experts from the National Highway and Traffic Safety Administration also conducted their own investigation, says Michels.
“While there is more detailed analysis to be done, we are able to review certain aspects of the testing and what was observed,” said Michels.
Toyota officials said Sikes rapidly pressed the gas and brakes back and forth 250 times, the maximum amount of data that the car’s self-diagnostic system can collect. That account appears to contradict Sikes’ statement – backed by the California Highway Patrol – that he was frantically slamming the brakes, at one point lifting his buttocks off the seat.
Toyota engineers employed data download/analysis, static and dynamic testing as well as thorough inspections of all relative components. In addition, they retraced the reported driving route taking into account driving time and accounts from the 911 recording.
The investigation revealed the following initial findings:
• The accelerator pedal was tested and found to be working normally with no mechanical binding or friction. It should be noted 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 front brakes showed severe wear and damage from overheating. The rear brakes and parking brake were in good condition and functional.
• A Toyota carpeted floor mat of the correct type for the vehicle was installed but not secured to the retention hooks. It was not found to be interfering or even touching the accelerator pedal.
• The pushbutton power switch worked normally and shut the vehicle off when depressed for 3 seconds as the 911 operator advised Mr. Sikes to do.
• The shift lever also worked normally and neutral could be selected. The neutral position is clearly marked and can be easily engaged by moving the lever left to the “N” marking.
• 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 did show evidence of numerous, rapidly repeated on-and- off applications of both the accelerator and the brake pedals.
• After examination of individual components, the front brakes were replaced and the vehicle was test driven, during which the vehicle was observed to be functioning normally.
• 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 Prius braking system uses both conventional hydraulic friction brakes and a regenerative braking system which switches the electric drive motors into brakes to generate electricity.
The system features a sophisticated self- protection function which cuts engine power if moderate brake pedal pressure is applied and the accelerator pedal is depressed more than approximately 50 percent, in effect providing a form of “brake override.”
Michels says 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 engineers believe that 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.