2023-2025 Audi Air Suspension Fault C118D01 TSB

Symptoms

Owners of affected 2023-2025 Audi vehicles may observe the message "Air suspension: system fault" displayed in the instrument cluster. This warning indicates a problem with the vehicle's air suspension system, potentially affecting ride height and comfort.

Fault Codes / DTCs

When diagnosing this issue, technicians will typically find the following Diagnostic Trouble Code (DTC) logged in the suspension control unit -J775- (diagnostic address 0074):

• C118D01: Compressor for level control electrical error.

This specific code points to an electrical malfunction within the air suspension compressor's control system.

Diagnosis and Trigger Conditions

Before proceeding with repairs, technicians are instructed to inspect the wiring and electrical contacts connected to the air compressor and the compressor electronics control unit -J1135-. This initial check helps rule out simple connection issues or damaged wiring as the cause of the "Audi air suspension fault C118D01" message.

Repair Procedure Summary

If no irregularities are found with the wiring or contacts, the primary repair involves replacing the control unit for the compressor electronics. It is important to note that only the control unit -J1135- should be replaced, not the entire air compressor assembly. The procedure typically includes:

1. Checking Wiring/Contacts: A thorough inspection of the electrical connections at the air compressor and compressor electronics -J1135-.
2. Control Unit Replacement: If the wiring is sound, the control unit for compressor electronics -J1135- is replaced. This is a critical step to resolve the Audi air suspension fault C118D01.
3. Battery Charge: The vehicle's battery should be charged as part of the service procedure.
4. Road Tests: Short road tests are performed both before and after the service procedure to verify the repair and ensure the air suspension system functions correctly.

Required Parts

For this repair, the following part is specified:

• 4M0.907.778: Control unit for compressor electronics J1135 (if necessary).

Fasteners, bolts, nuts, and screws should be obtained as needed per the repair manual (ETKA/ELSA).

Warranty Information

This Technical Service Bulletin (TSB 2073034/6) outlines specific warranty claim types for the repair:

• Claim Type 110: Covers vehicles up to 48 months or 50,000 miles. Owners should verify their coverage.
• Claim Type G10: Applicable for Audi Certified Pre-Owned (CPO) vehicles. Owners of CPO vehicles should also verify their specific coverage details.

Important Warnings

Owners should be aware that if their vehicle falls outside of the specified warranty periods (48 months/50,000 miles or CPO coverage), this Technical Service Bulletin is provided for informational purposes only. In such cases, the cost of diagnosis and repair may not be covered by Audi.

TSB Revision History

Technical Service Bulletin 2073034/6 has undergone several revisions to ensure accuracy and provide updated information:

• Revision 6: Updated the service procedure.
• Revision 5 (May 14, 2024): Revised warranty labor operations and added model years to the header.
• Revision 4 (May 7, 2024): Revised the service procedure.

This bulletin supersedes Technical Service Bulletin Group 43 number 24-90, dated May 14, 2024.

Owner Action

If your 2023-2025 Audi displays the "Air suspension: system fault" message or you suspect an Audi air suspension fault C118D01, it is recommended to schedule an appointment with an authorized Audi service center. They will be able to diagnose the issue using the specific DTCs and perform the necessary repair as outlined in TSB 2073034/6.

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Source: NHTSA ID: 11003014