2021 Audi A4/A5/A6/Q5 Starter Generator Belt Noise TSB

Audi has issued Technical Service Bulletin (TSB) 13 23 16 2061461/6, superseding an earlier bulletin (Group 20 number 22-50 dated October 27, 2022), to address concerns with the starter/generator drive belt in certain 2021 Audi A4, A5, A6, and Q5 models equipped with the 2.0L engine. Owners may experience unusual noises from the engine compartment or a specific warning message on the instrument cluster. This TSB outlines the diagnostic steps and repair procedures for these conditions.

Symptoms

Owners of affected 2021 Audi A4, A5, A6, and Q5 vehicles may notice one or more of the following symptoms:

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

Fault Codes / DTCs

When these symptoms occur, the engine control module (ECM), identified as J623 (address word 0001), may store a specific diagnostic trouble code:

Code	Description
P2BA300	Starter/Generator mechanical performance

Diagnosis / Trigger Conditions

The root cause of the 2021 Audi A6 starter generator belt issue is often a deviation on the rollers of the belt tensioner. This can lead to the poly V-belt becoming noisy, damaged, or dislodged.

To confirm the source of grinding, squeaking, or tweeting noises, technicians are instructed to run the engine at idle and assess the sound. A common diagnostic step involves spraying a small amount of tap water onto the inside of the poly V-belt. If the noise disappears after this, it confirms the belt as the source.

Repair Procedure Summary

The repair procedure outlined in TSB 13 23 16 2061461/6 depends on the observed symptoms:

Scenario 1: Grinding, Squeaking, or Tweeting Noises

1. The technician will first assess the noise with the engine running at idle speed.
2. To confirm the noise source, a small amount of water will be sprayed onto the poly V-belt. If the noise stops, the belt is the cause.
3. If the water spray test confirms the belt as the noise source, both the poly V-belt and the belt tensioner should be replaced.

Scenario 2: Poly V-belt Damaged or Fallen Off

1. In cases where the poly V-belt is damaged or has fallen off, both the belt tensioner and the poly V-belt must be replaced.

After replacing the poly V-belt and tensioner, it is crucial to check for correct belt running alignment. The belt must not protrude forward or backward over the roller edge of the tensioner when the engine is running at idle.

Important Warnings

Owners and technicians should be aware of a critical instruction regarding the belt tensioner replacement:

• If a new belt tensioner has already been installed, do not replace it again.

Required Parts and Tools

Specific parts are required for this repair. Technicians should consult ETKA (Audi's electronic parts catalog) for the latest information and part numbers:

• Belt Tensioner: Quantity 01 (See ETKA)
• Poly-V Belt: Quantity 01 (See ETKA)
• Fasteners, Bolts, Nuts, and Screws: As needed per the Repair Manual (See ETKA/ELSA)

Warranty Information

Warranty claims for this issue are covered under the following conditions:

• Standard Warranty: Up to 48 Months/50,000 Miles.
• Certified Pre-Owned (CPO) Vehicles: G10 claim type, requiring owner verification.
• If the vehicle is outside of any applicable warranty, this Technical Service Bulletin serves as informational guidance only.

Damage codes associated with this repair are 0020 for a noisy belt and 0015 if the belt came off. Labor operations include 'Ribbed belt remove + install' (1372 1915), 'Belt tension damper remove + install' (1373 1965), and 'Check Poly V-Belt run alignment' (1372 0199).

NHTSA ID: 10230588