Engine Controls - Cold Misfire/MIL ON/DTC P0300-P0308

01 MIL on, cold start misfire (DTCs P0300 - P0308)

24 10 46

2024048/1

August 4, 2010





Affected Vehicles

Condition

^ MIL on.

^ Engine runs rough (misfires) after cold start.

^ The following DTCs are logged in the memory of the ECM: DTC P0300 - P0308 (misfire).

This condition will not cause stalling or drivability concerns.

Technical Background

The cause is the software of the ECM.

Over the last 3 years the capability of fuel available in the United States to evaporate at low temperatures (~32-80°F) has decreased, while still being within the tolerance band of EPA specification.

Initial engine calibration was based on worst case fuel blend at the time.

The 2008 RS4 engine is more sensitive to changes in evaporative behavior of fuel. Also the variation in Ethanol content (0-10%) influences the engine calibration requirements. In order to adjust to the shift in the evaporative behavior of available fuel, the engine control software was updated.

Production Solution

Not applicable.

Service

1. Follow all instructions in the attached TSB 2011732 00 Software Version Management (SVM), operating instructions.

2. Update the ECM software of the affected vehicles (two ECMs for RS4) using the SVM action code as listed in the table below if necessary.





3. Allow the car to sit overnight.

4. Ensure ambient temperatures are between 40 - 80°F.

5. Confirm repair under cold start condition.

Tip: There is only one cold start per day, and the ambient temperatures must be between 40-80°F.

If no misfire is detected, the repair was successful.





Warranty

Additional Information

All parts and service references provided in this TSB are subject to change and/or removal. Always check with your Parts Department and service manuals for the latest information.


























Attachment - 00 Software Version Management (SVM), operating instructions