2021-2023 Audi Belt Noise & DTC P2BA300 TSB

Owners of affected Audi models may experience Audi A6 starter generator belt noise or other related symptoms. This Technical Service Bulletin (TSB) 2061461/9, released on March 8, 2024, supersedes previous bulletin 23-20 dated October 13, 2023, and addresses issues with the starter/generator drive belt and its tensioner.

Symptoms

Owners might notice the following issues with their vehicle:

• A grinding, squeaking, or tweeting noise originating from the engine compartment.
• A warning message displayed in the driver information system (DIS) stating, "Electrical system: Malfunction! Please go to workshop." This message typically appears if the poly V-belt has fallen off.

Workshop technicians may find that the grinding/squeaking/tweeting noise is specifically coming from the poly V-belt (alternator belt). Additionally, the poly V-belt might be damaged or have fallen off its wheel roller.

Fault Codes / DTCs

In some cases, the Engine Control Module (ECM) may store the diagnostic trouble code (DTC):

• P2BA300

Diagnosis

To diagnose the Audi A6 starter generator belt noise or related issues, technicians will perform specific checks:

1. Noise Assessment: The engine will be run at idle speed to assess the noise. A video example of the noise is available via a QR code in the original TSB document.
2. Water Spray Test: To confirm the noise source, a small amount of tap water will be sprayed onto the inside of the poly V-belt. If the noise disappears after this, it indicates the poly V-belt and belt tensioner are the source of the problem.

Important Warnings

Audi has issued several critical advisories for technicians and owners regarding this repair:

• Do not replace the belt-driven starter-generator: Replacing this component will not resolve the problem.
• Do not replace already installed new belt tensioners: If a new belt tensioner has already been installed, it should not be replaced again.
• Damage to components during removal: Technicians must ensure the belt tensioner (including its retaining tab) is not damaged during removal. Damage to the component could prevent proper analysis, and Audi may charge back the cost of damaged parts.

Repair Procedure Summary

The repair procedure outlined in TSB 2061461/9 involves addressing the belt tensioner and poly V-belt based on the observed symptoms:

Scenario 1: Grinding, Squeaking, or Tweeting Noises

If the water spray test confirms the poly V-belt and belt tensioner as the source of the noise, both the poly V-belt and the belt tensioner should be replaced.

Scenario 2: Poly V-belt Damaged or Fallen Off

If the poly V-belt is found to be damaged or has fallen off, both the belt tensioner and the poly V-belt should be replaced.

After replacement, it is crucial to check the correct running alignment of the 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. Figure 2 in the TSB illustrates the correct alignment.

Required Parts

Technicians will need to consult the Electronic Technical Information System (ETKA) for the most current part numbers for the following components:

• Fasteners, Bolts, Nuts, and Screws (as needed per the Repair Manual)
• Belt Tensioner
• Poly-V Belt

Warranty Information

This repair is covered under Audi's warranty for up to 48 months or 50,000 miles. For Certified Pre-Owned (CPO) vehicles, coverage falls under G10, requiring owner verification. If the vehicle is outside of its warranty period, this Technical Service Bulletin serves as informational guidance only.

Service Number: 1373

Damage Codes:

• 0020 (Noisy belt)
• 0015 (Belt came off)

Labor Operations:

• Ribbed belt remove + install: 1372 1915
• Belt tension damper remove + install: 1373 1965 (10 Time Units)
• Check Poly V-Belt run alignment: 1372 0199 (10 Time Units)
• Road test prior to service procedure: No allowance
• Road test after service procedure: No allowance

Warranty claims should be submitted in accordance with the Audi Warranty Policies and Procedures Manual.

---

NHTSA ID: 10251619