2021 Audi Cylinder Misfire DTCs P0300-P0306 TSB

Symptoms of Cylinder Misfires

Owners of affected 2021 Audi vehicles may experience an illuminated Malfunction Indicator Lamp (MIL) on the dashboard. This warning light indicates that the engine's onboard diagnostic system has detected a fault, specifically cylinder misfires. If your 2021 Audi Q8 cylinder misfire issue triggers the MIL, it's important to have it diagnosed promptly.

Fault Codes / DTCs

When the MIL illuminates due to cylinder misfires, the vehicle's diagnostic system may store one or more of the following Diagnostic Trouble Codes (DTCs):

Technical Background

Audi has identified that the cylinder misfires and the resulting MIL illumination are caused by a software issue within the engine control module (ECM), specifically the J623 control unit (address word 0001). An optimized software version is available to correct this condition, preventing misfires and turning off the MIL.

Repair Procedure Summary

The repair involves updating the software in the engine control module (ECM). This procedure is outlined in Technical Service Bulletin 01 24 21 2069038/6, which supersedes previous bulletins Group 01 number 23-91 dated November 1, 2023. The update utilizes the Software Version Management (SVM) system. Technicians must follow the instructions in TSB 2011732 for SVM operating procedures. The ECM (J623) will be updated using the SVM action code 01A255 as listed in the table below, which specifies the required software part numbers and versions for various models and model years.

This TSB also replaces previous Pending Service Solutions (PSS) 2054182 (for 3.0 TFSI Bank 2 engine misfires in Q8/Q7 DCBD engines) and 2058038 (for 3.0 TFSI engine misfires in A6 and A7 with DTCs P0300 through P0306).

Required Tools

To perform the software update, technicians will need a VAS tester with the current version of ODIS (Windows 10). Specifically, the VAS 6160 or VAS 6150 tools are required.

Warranty Information

This repair is covered under warranty for up to 48 months or 50,000 miles, whichever comes first. For Certified Pre-Owned (CPO) vehicles, the claim type is G10, requiring verification of ownership. If your vehicle is outside of these warranty parameters, this Technical Service Bulletin serves as informational guidance only, and repair costs may apply. The service number for this procedure is 2470, with a damage code of 0039, and labor operations for software update (0151 0010) and diagnostic time (0151 0060).

What Owners Should Know

If your 2021 Audi Q8 cylinder misfire issue persists or if your MIL is illuminated, contact your authorized Audi dealer. They can diagnose the issue, confirm the presence of DTCs like P0300, and perform the necessary software update as described in TSB 01 24 21 2069038/6. Ensure to mention this TSB number when discussing the issue with your service advisor.

Source: NHTSA ID: 11002110