NHTSA safety investigation
NHTSA Investigation PE04023
Preliminary Evaluation · Volkswagen Group of America, Inc. · FUEL SYSTEM, GASOLINE
An investigation is not a finding that a defect exists.
NHTSA opens an investigation to examine whether a safety defect may exist. An open investigation is not a determination that a defect exists, and many investigations close without a recall. Investigations can, however, lead to one.
What NHTSA is examining
The agency's own description of the inquiry, quoted as published
STUCK-OPEN THROTTLE
COMPLAINTS RECEIVED BY ODI AND AUDI ALLEGE THAT, IN EXTREME COLD WEATHER, THE THROTTLE MAY UNEXPECTEDLY FAIL TO RETURN TO IDLE WHEN THE ACCELERATOR PEDAL IS RELEASED, MAKING IT DIFFICULT TO STOP THE VEHICLE.IN MARCH OF 2004, AUDI PERFORMED A SERIES OF TESTS TO INVESTIGATE THE POSSIBLE CAUSES OF THROTTLE ICING.AUDI CONCLUDED THAT UNDER CERTAIN DRIVING CONDITIONS - ONLY SHORT DISTANCE TRIPS OVER SEVERAL WEEKS WHERE COOLANT TEMPERATURE REMAINS BELOW 70?C (158?F) - WATER MAY ACCUMULATE IN THE MOTOR OIL. WATER THAT HAS ACCUMULATED IN THE MOTOR OIL WILL EVAPORATE AFTER THE ENGINE OIL TEMPERATURE EXCEEDS 70?C (158?F) AND COULD, WITHIN 15 TO 20 MINUTES OF DRIVING AT A CONSTANT SPEED WITH AN OUTSIDE TEMPERATURE BELOW -20?C (-4OF), CAUSE ICE TO FORM IN THE THROTTLE BODY.ACCORDING TO AUDI, THIS CONDITION OCCURS AT RELATIVELY LOW THROTTLE SETTINGS AND RESULTS IN THROTTLE STICKING AT POSITIONS THAT CAN BE CONTROLLED BY BRAKING.DURING TYPICAL VEHICLE USAGE (MIXTURE OF SHORT AND LONG DISTANCE DRIVING) THIS PHENOMENON IS NOT EXPECTED TO OCCUR.THIS INVESTIGATION HAS BEEN UPGRADED TO AN ENGINEERING ANALYSIS.
An investigation is a separate record from a recall and from a manufacturer communication. A manufacturer campaign to repair a safety defect or a failure to meet a federal safety standard.
Investigation details
Identifiers, dates and outcome as recorded by NHTSA
- Action number
- PE04023
- Investigation type
- Preliminary Evaluation (PE)
- Status
- Closed
- Manufacturer
- Volkswagen Group of America, Inc.
- Component
- FUEL SYSTEM, GASOLINE
- Opened
- Mar 5, 2004
- Closed
- Jun 30, 2004
- Associated recall campaign
- None recorded
Vehicles named in this investigation
2 model years across 1 model
Being named here means NHTSA included the vehicle in the scope of its inquiry. It is not a statement that these vehicles have a defect.