2021 Audi Q8, A6, A7 MIL On with Misfire DTCs P0300-P0306

Symptoms of Cylinder Misfires and MIL Illumination

Owners of affected 2021 Audi models may notice that the "MIL is illuminated" (Malfunction Indicator Lamp) on their dashboard. This warning light indicates a detected issue within the engine system. The underlying problem is typically related to cylinder misfires, which can affect engine performance and fuel efficiency.

Fault Codes (DTCs)

When the MIL illuminates due to this condition, technicians will likely find one or more of the following Diagnostic Trouble Codes (DTCs) stored in the vehicle's engine control module (ECM):

These codes specifically point to misfire events occurring in one or multiple cylinders, triggering the "MIL is illuminated" warning.

Diagnosis and Trigger Conditions

The root cause of the "MIL is illuminated" warning and the associated misfire DTCs P0300-P0306 is identified as outdated software within the engine control module (ECM), specifically the J623 control module (address word 0001). This software deficiency can lead to improper engine operation, resulting in misfires. The updated software is designed to optimize engine parameters and prevent these misfire conditions from occurring.

This Technical Service Bulletin (TSB) 2069038/6 supersedes previous bulletins addressing similar issues, including Group 01 number 23-91 dated November 1, 2023. It also replaces Pending Service Solutions (PSS) TSB 2054182, which covered PSS 01 3.0 TFSI Bank 2 engine misfires in Q8/Q7 (DCBD engine), and TSB 2058038, which addressed PSS 01 3.0 TFSI engine misfires in A6 and A7 models with DTCs P0300 through P0306.

Repair Procedure Summary

The recommended repair for the "MIL is illuminated" and misfire DTCs P0300-P0306 involves updating the software of the engine control module (ECM), also known as the J623 control unit. This update ensures the ECM operates with the latest calibrations to prevent misfires.

The service procedure requires following the instructions detailed in TSB 2011732, which outlines the general operating procedures for 00 Software Version Management (SVM). Technicians will update the ECM using a specific SVM action code. For the 2021 Audi Q8 and other affected models, the SVM Code Input is 01A255. The table below provides a summary of the software part numbers and versions involved in this update:

This software update ensures that the engine control module is running the most current and optimized program to prevent the occurrence of cylinder misfires and the illumination of the MIL.

Required Tools

To perform the software update for the ECM, technicians will need specific diagnostic equipment. The primary tool required is a VAS tester, specifically the VAS 6160/VAS 6150, which must be running the current version of ODIS (Offboard Diagnostic Information System) on a Windows 10 operating system. This specialized equipment is essential for correctly flashing the new software to the J623 control module.

Important Warnings

Owners should be aware of the warranty implications for this repair. The software update described in TSB 2069038/6 is typically covered under warranty for up to 48 months or 50,000 miles, whichever comes first. For Audi Certified Pre-Owned (CPO) vehicles, the repair may be covered under claim type G10, provided the owner's eligibility is verified. If the vehicle falls outside of any applicable warranty period, this Technical Service Bulletin is for informational purposes only, meaning the cost of the repair would likely be the owner's responsibility.

What Owners Should Do

If you own a 2021 Audi Q8, A6, A7, or other affected model and experience the "MIL is illuminated" warning light accompanied by symptoms of engine misfires, it is recommended to contact your authorized Audi dealership. Inform them about the symptoms and the potential relevance of Technical Service Bulletin 2069038/6. The dealership will be able to diagnose the specific DTCs, such as P0300, P0301, P0302, P0303, P0304, P0305, or P0306, and perform the necessary ECM software update.

Source: NHTSA ID: 11002210