2021 Audi A6 Drive Belt Noise, DTC P2BA300

Symptoms

Owners of affected 2021 Audi A6, A4, A5, and Q5 vehicles may notice a distinct grinding, squeaking, or tweeting noise originating from the engine compartment. In more severe cases, particularly if the poly V-belt has come off, the driver information system (DIS) may display the warning message, "Electrical system: Malfunction! Please go to workshop."

Fault Codes / DTCs

When diagnosing the issue, technicians may find the following diagnostic trouble code (DTC) stored in the engine control module (ECM), specifically J623 (address word 0001):

• P2BA300: Starter/Generator mechanical performance

Diagnosis / Trigger Conditions

The root cause of these issues is often a deviation on the rollers of the belt tensioner. To confirm the source of the noise, a technician can run the engine at idle speed and listen for the characteristic grinding, squeaking, or tweeting sounds. A simple diagnostic step involves spraying a small amount of water onto the inside of the poly V-belt; if the noise temporarily disappears, it confirms the belt as the source.

Repair Procedure Summary

Audi Technical Service Bulletin 2061461/4 outlines two primary repair scenarios:

• Scenario 1: Grinding, Squeaking, or Tweeting Noises: If the noise is confirmed to be coming from the poly V-belt and disappears after spraying with water, the poly V-belt and belt tensioner must be replaced. This addresses the deviation on the tensioner rollers.
• Scenario 2: Damaged or Fallen-Off Poly V-belt: If the poly V-belt is found to be damaged or has come off the wheel roller, both the belt tensioner and the poly V-belt require replacement.

After replacing these components, it is crucial to check the correct running alignment of the new poly V-belt. The engine should be run at idle speed, and the belt must not protrude forward or backward over the roller edge of the tensioner. This ensures proper operation and prevents recurrence of the 2021 Audi A6 P2BA300 issue.

Required Parts

For the repair, the following parts are typically required:

• Fasteners, Bolts, Nuts, and Screws: As needed per the repair manual (check ETKA for specifics).
• Belt Tensioner: Quantity 01 (check ETKA for specific part number).
• Poly-V Belt: Quantity 01 (check ETKA for specific part number).

Important Warnings

Warranty coverage for this repair is generally available for vehicles up to 48 months or 50,000 miles. For Audi Certified Pre-Owned (CPO) vehicles, coverage is also provided, though verification with the owner is necessary. If your vehicle falls outside of these warranty parameters, this Technical Service Bulletin serves as informational guidance only, and the repair costs may not be covered.

NHTSA ID: 10199211