2025 Audi A3/S3/RS3 Remote Key / Infotainment Issues TSB

Symptoms

Owners of 2025 Audi A3, S3, and RS3 models may experience one or both of the following issues:

• The "Remote control key does not work."
• "Issues with infotainment functions (usability/reaction)".

Workshop findings indicate that the "Remote function of all keys does not work (static)." However, the keyless start and keyless opening functions (if fitted) are always available, meaning the vehicle can still be started and unlocked without the remote function. These symptoms often point to the underlying issue affecting the "Audi S3 remote key" and related systems.

Fault Codes / DTCs

When these symptoms occur, the control unit for information electronics J794, which has diagnostic address 005F, may log specific Diagnostic Trouble Codes (DTCs):

Code	Description
U10B800	Local data bus faulty.
U10FA00	Local data bus single wire mode.

Diagnosis / Trigger Conditions

The root cause for the remote key and infotainment issues, as detailed in TSB 2074986/1, is a trapped wire located under charging unit 1 for mobile devices (component J1146). This wiring irregularity can disrupt the local data bus, leading to the observed malfunctions and logged DTCs like U10B800 and U10FA00.

Repair Procedure Summary

The repair involves inspecting and correcting the wiring under the charging unit 1 for mobile devices (component J1146) in the front center console. Technicians will look for any routing irregularities in the wiring harness, as illustrated in the bulletin's Figures 1 and 2. Figure 1 shows the charging unit 1 for mobile devices removed, while Figure 2 highlights a trapped wiring harness. If a trapped or damaged wire is found, the wiring harness must be repaired using a specialized wiring harness repair set, specifically VAS 1978 B/C. For warranty claims, a photo clearly showing the complaint must be attached to DOC-IT.

Required Tools or Parts

To perform the repair described in TSB 2074986/1, the following special tool is required:

• VAS 1978 B/C: Wire harness repair set.

Warranty Information

This Technical Service Bulletin provides specific details for warranty claims:

• Claim Type: If the vehicle is outside of any warranty, this Technical Service Bulletin is informational only.
• Service Number: 9709
• Damage Code: 0024
• Labor Operations:
  • Remove and install phone tray: 9108 1900 (See SRT with associated operations)
  • Remove and install center console insert: 6817 1999 (20 TU)
  • Check wiring harness: 9709 0199 (10 TU)
  • Repair wiring harness (depending on number of wires): 9709 41xx (See SRT with associated operations)
  • GFF / Guided Functions: 0150 0060 (Time stated on the diagnostic protocol)
• Claim Comment: As per TSB 2074986

All warranty claims submitted for payment must be in accordance with the Audi Warranty Policies and Procedures Manual and are subject to review or audit by Audi Warranty.

Owner Action

If you are experiencing problems with your "Audi S3 remote key" or infotainment system in your 2025 Audi A3, S3, or RS3, and especially if you notice the symptoms described above, it is recommended to visit an authorized Audi service center. Inform them about the specific issues and mention Technical Service Bulletin 2074986/1. The technicians can diagnose the problem by checking for the relevant DTCs (U10B800, U10FA00) and inspecting the wiring harness under the mobile device charging unit.

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Source: NHTSA ID: 11007239