Toyota Offers Preliminary Findings From Technical Field Examination of Alleged 'Runaway Prius' in San Diego
Toyota Engineers Conclude Two Days of Investigation
Drivers Account Of Event Inconsistent With Initial Findings
March 15, 2010 - San Diego, CA, - At a press conference today, Toyota Motor
Sales (TMS), U.S.A., Inc. offered key preliminary findings of technical field
examination and testing that were performed on March 10 and 11 regarding an alleged
runaway Prius event dramatically covered by national news media.
Toyota
engineers completed an investigation of the 2008 Prius driven by Mr. James Sikes
that was the subject of a 911 emergency call on Monday, March 8. The driver reported
that the vehicle was traveling at a high rate of speed, the accelerator pedal
was stuck, and that the vehicle was out of control and could not be stopped. The
emergency operator repeatedly instructed the driver 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 complete, there are strong indications that
the driver's account of the event is inconsistent with the findings of the preliminary
analysis.
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.
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.
These findings
suggest that there should be further examination of Mr. Sikes account of the events
of March 8.
NHTSA investigators were present during Toyotas examination,
and are conducting their own investigation of the vehicle and its performance.
Toyotas examination was also observed by a congressional staff member.
