2021 Audi A6/A7 Engine Misfires (DTCs P0300-P0306)

Symptoms

Owners of affected vehicles may notice their Malfunction Indicator Lamp (MIL) illuminated on the dashboard. This warning light signals a potential issue with the engine or emissions system. The primary symptom is the occurrence of engine misfires, particularly under specific operating conditions.

Fault Codes / DTCs

When diagnosing this condition, technicians may find one or more of the following Diagnostic Trouble Codes (DTCs) stored in the vehicle's system:

• DTC P0300: Random/Multiple Cylinder Misfire Detected
• DTC P0301: Cyl.1 Misfire Detected
• DTC P0302: Cyl.2 Misfire Detected
• DTC P0303: Cyl.3 Misfire Detected
• DTC P0304: Cyl.4 Misfire Detected
• DTC P0305: Cyl.5 Misfire Detected
• DTC P0306: Cyl.6 Misfire Detected

These codes indicate that the engine's combustion process is not occurring correctly in one or more cylinders, leading to the reported Audi A6 engine misfires.

Technical Background and Diagnosis

The root cause of the Audi A6 engine misfires is identified as a software calibration issue. This condition is particularly prone to occurring when the vehicle is operating with winter blend fuel, which has a higher vapor pressure. The misfires are most common during colder winter months due to this interaction between the software and fuel type.

Important Warnings

Audi explicitly states that owners and technicians should not replace any components to address this misfire condition. Replacing parts will not resolve the underlying software calibration issue and would be an unnecessary expense. The manufacturer is developing a software-based solution.

Repair Procedure Summary

As of the bulletin's publication, an improved software solution is currently in development. Audi anticipates that this solution will be available by the end of the 4th quarter of 2023, though this timeline is subject to change. No physical repairs or component replacements are necessary or recommended at this time for the Audi A6 engine misfires related to this TSB.

Owner Action

If your 2021 Audi A6, A7, or A6 allroad is experiencing engine misfires and has illuminated the MIL, and diagnostic checks confirm the presence of DTCs P0300 through P0306, you should be aware that a software fix is forthcoming. There is no need for immediate repairs or component replacement. Owners should contact their authorized Audi dealer to report the condition and inquire about the availability of the software update once it is released. Dealers are instructed to create a Pending Service Solutions (PSS) record for affected vehicles. For additional information regarding earlier model years, refer to TSB 2069038 for Model Year 2019 and 2021 A6/A7 vehicles.

NHTSA ID: 10244471