NHTSA Office of Defects Investigation

Preliminary Evaluation PE04-023: STUCK-OPEN THROTTLE

Closed

NHTSA's Office of Defects Investigation opened Preliminary Evaluation PE04-023 on March 5, 2004 and closed it on June 30, 2004. NHTSA's investigations file lists the 1998–1999 Audi A6 for it.

Updated daily from NHTSA's investigations file

Key facts

NHTSA number: PE04-023 (also written PE04023)
Investigation type: Preliminary Evaluation The first stage of most defect investigations: NHTSA's Office of Defects Investigation gathers basic information about a possible safety defect, including from the manufacturer.
Status: Closed June 30, 2004
Opened: March 5, 2004
Closed: June 30, 2004
Vehicle or equipment manufacturer: Volkswagen Group of America, Inc.
Components: Fuel System, Gasoline; Vehicle Speed Control; Vehicle Speed Control — Cables; Vehicle Speed Control — Linkages
Vehicles and equipment: 1998–1999 Audi A6

A recall appears here only when NHTSA's investigations file links one to the investigation; NHTSA's summary or record can name others.

NHTSA's summary

As NHTSA's Office of Defects Investigation wrote it for Preliminary Evaluation PE04-023.

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.

Vehicles and equipment listed for this investigation

NHTSA's investigations file lists these vehicles and equipment for Preliminary Evaluation PE04-023. A listed model year means only that an investigation names it; it says nothing about any particular vehicle. Model years with a try.vin recall page link to that page's NHTSA investigations section.

Audi

Audi A6
- 1998, 1999

All Audi recalls

What an NHTSA investigation is

NHTSA's Office of Defects Investigation (ODI) looks into possible safety defects in vehicles and equipment, often after owner complaints. An investigation usually starts as a Preliminary Evaluation, or as a Recall Query when it concerns whether an existing recall covers the right vehicles or fixes the problem, and ODI can upgrade it to a more detailed Engineering Analysis. A Defect Petition asks NHTSA to open an investigation, and Audit and Equipment Queries are administrative investigations into whether companies complied with federal vehicle safety requirements, such as reporting, recall and certification rules.

An open investigation is not a finding that a safety defect exists, and NHTSA can close one without a recall.

To see whether a specific vehicle has an open recall, enter its VIN at nhtsa.gov/recalls.

Audi VIN check: decode a VIN to see its year, make and model.

Sources

NHTSA's investigation record for PE04-023

Investigation details come from NHTSA's investigations file, which try.vin imports once a day. The investigation types are described from the U.S. Department of Transportation Inspector General's May 2023 report on NHTSA's Office of Defects Investigation, NHTSA's petition rules (49 CFR Parts 552 and 557) and NHTSA's Office of Defects Investigation procedures. How try.vin reads NHTSA investigations.