2023-2025 Audi Air Suspension Fault DTC C118D01

Owners of certain 2023-2025 Audi vehicles equipped with air suspension may encounter a warning message in their instrument cluster indicating an Audi air suspension fault. This issue is specifically addressed by Audi Technical Service Bulletin (TSB) 2073034/6.

This TSB, dated June 28, 2024, supersedes a previous bulletin, Group 43 number 24-90, from May 14, 2024, due to updated procedures and warranty information. The bulletin aims to provide technicians with the necessary steps to diagnose and repair the underlying cause of this air suspension system fault.

Symptoms

If your Audi is affected, you will likely see the message "Air suspension: system fault" displayed prominently in the instrument cluster. This message indicates a problem with the vehicle's air suspension system, which could impact ride height, comfort, and handling.

Fault Codes / DTCs

When a technician scans the vehicle's systems, the following Diagnostic Trouble Code (DTC) will be found in the suspension control unit -J775- (diagnostic address 0074):

• C118D01: Compressor for level control electrical error.

This specific DTC points directly to an electrical issue within the air suspension compressor's control system, confirming the Audi air suspension fault.

Technical Background

The root cause of the Audi air suspension fault and the associated DTC C118D01 is an electrical error within the compressor for the level control system. This component is crucial for maintaining the correct ride height and functionality of the air suspension. The TSB provides a detailed procedure to address this specific electrical malfunction.

Repair Procedure Summary

To resolve the Audi air suspension fault, technicians will first inspect the wiring and contacts at both the air compressor and the compressor electronics control unit -J1135-. If no irregularities are found during this initial check, the next step is to replace the control unit for the compressor electronics -J1135-. It is important to note that only the control unit is replaced, not the entire air compressor assembly.

This procedure involves removing and installing the control unit -J1135-. Additionally, the vehicle's battery may need to be charged as part of the service process. Diagnostic time is allocated for troubleshooting, and road tests are performed both before and after the service to confirm the repair.

Required Parts

For the repair of the Audi air suspension fault, the primary part required is the control unit for compressor electronics. The TSB specifies the following part number:

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

Additionally, fasteners, bolts, nuts, and screws may be needed as per the repair manual, which can be referenced through ETKA/ELSA.

Warranty Information

This Technical Service Bulletin outlines warranty coverage for the repair. The claim type is 110, covering vehicles up to 48 months or 50,000 miles. For Audi Certified Pre-Owned (CPO) vehicles, the claim type is G10, but owners should verify coverage. All warranty claims must adhere to the Audi Warranty Policies and Procedures Manual.

Important Warnings

Owners should be aware that if their vehicle is outside of its warranty period, this Technical Service Bulletin is considered informational only. This means that the repair costs may not be covered by Audi, and owners would be responsible for the expense.

FAQs

Q1: What does DTC C118D01 specifically indicate? A1: DTC C118D01 indicates an electrical error within the compressor for the level control system, which is part of your Audi's air suspension system.

Q2: Will I see a warning light or message for this issue? A2: Yes, if your Audi experiences this fault, you will typically see the message "Air suspension: system fault" displayed in your instrument cluster.

Q3: What is the primary repair for this Audi air suspension fault? A3: The primary repair involves inspecting wiring and, if necessary, replacing the compressor electronics control unit -J1135- (part number 4M0.907.778), as detailed in TSB 2073034/6.

Q4: Is this repair covered by warranty? A4: For vehicles within 48 months or 50,000 miles, or for CPO vehicles, the repair may be covered under warranty. However, if your vehicle is outside of warranty, the TSB is for informational purposes only, and you may be responsible for the cost.

Q5: What is the TSB number for this issue? A5: The relevant Technical Service Bulletin is 43 24 91 2073034/6, which supersedes TSB 24-90.

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Source: NHTSA ID: 11002945