2021-2025 Audi Q7/Q8 Active Roll Stabilization DTC C129700

Audi has released Technical Service Bulletin (TSB) 2067804/5 to address concerns in 2021-2025 Audi Q7, SQ7, Q8, SQ8, and RS Q8 vehicles related to the active roll stabilization system. Owners may experience warning messages such as "Air suspension fault" or "roll stabilization/suspension" in the instrument cluster, often accompanied by Diagnostic Trouble Code (DTC) C129700. This TSB provides a detailed diagnostic and repair procedure for the Audi Q8 active roll stabilization system.

Symptoms

Owners of affected Audi vehicles may observe one of the following messages displayed in the instrument cluster: "Air suspension fault" or a message concerning the "roll stabilization/suspension." Other reported symptoms include a "shock absorber control system malfunction display" or a "stabilizer bar decoupling indicator display."

Fault Codes / DTCs

When diagnosing this issue, technicians will typically find the following Diagnostic Trouble Code (DTC) logged:

Code	Description	Diagnostic Address	Storage State
C129700	Function limitation due to malfunction in sway control module	00D4 (Sway stabilization 1)	static, intermittent
C129700	Function limitation due to malfunction in sway control module	00D5 (Sway stabilization 2)	static, intermittent
C129700	Function limitation due to malfunction in sway control module	0074 (Chassis control)	static, intermittent

This DTC is associated with symptom code 12664851.

Diagnosis / Trigger Conditions

Workshop findings indicate that DTC C129700 is logged in one of the two roll stabilizer control units, J924 or J1096, which correspond to diagnostic addresses 00D4 or 00D5. The fault code, C129700, signifies a "Function limitation due to malfunction in sway control module," directly impacting the Audi Q8 active roll stabilization system.

Important Warnings

Repair Procedure Summary

The initial repair procedure outlined in TSB 2067804/5 focuses on resetting the system and clearing the fault codes. If no other suspension or roll stabilization DTCs are present, technicians should perform the following sequence:

1. Unplug the diagnostic connector from the vehicle.
2. Switch off the ignition.
3. Lock the vehicle, ensuring doors, hood, and rear lid are closed.
4. Wait until the vehicle has entered bus sleep mode.
5. Unlock the vehicle.
6. Plug the diagnostic connector back into the vehicle.
7. Switch on the ignition.
8. Attempt to erase the DTCs.

If DTC C129700 remains logged after these steps, technicians are instructed to follow the Guided Fault Finding (GFF) instructions to further diagnose and resolve the issue. It is crucial to note that the control unit itself should not be replaced as part of this initial procedure for the Audi Q8 active roll stabilization system.

Warranty Information

Audi provides specific guidelines for warranty claims related to this TSB. If the vehicle is outside its warranty period, this bulletin serves as informational guidance only. The service number for this repair is 4024, with a damage code of 0040. Labor operations include 'Charge battery' (code 2706 8950), 'Check vehicle (BUS Sleep mode)' (code 0689 0199, 10 TU), and 'Guided Fault Finding (GFF)' (code 0150 0000, with time stated on the diagnostic protocol). All warranty claims must adhere to the Audi Warranty Policies and Procedures Manual, and are subject to review or audit by Audi Warranty.

Source: NHTSA ID: 11016516