2021 Audi Q8 MIL On: EVAP Leak DTC P044200 P045600

Owners of certain 2021 Audi models, including the Audi Q8, may experience an illuminated Malfunction Indicator Lamp (MIL) on their dashboard. This warning light is often accompanied by specific diagnostic trouble codes (DTCs) related to the Evaporative Emission (EVAP) system. This issue is addressed by Audi Technical Service Bulletin (TSB) 20 22 49 2065287/4, which outlines the cause and necessary repair.

This TSB, identified as 20 22 49 2065287/4, supersedes an earlier bulletin, Group 20 number 22-42, dated April 7, 2022. The current revision, Revision 4, was issued on September 14, 2022, with updates to header data and symptom codes.

Symptoms

The primary symptom reported by owners is the illumination of the Malfunction Indicator Lamp (MIL) on the instrument cluster. This indicates a detected issue within the vehicle's emission control system. When scanned, the vehicle's engine control module (ECM), also known as J623 (address word 0001), will store specific diagnostic trouble codes.

Fault Codes / DTCs

If your 2021 Audi Q8 has an illuminated MIL, a diagnostic scan may reveal one or both of the following fault codes:

Code	Description	Symptom Code
P044200	EVAP Emissions Control System (Small Leak) Detected	11955
P045600	EVAP Emissions Control System (Very Small Leak) Leak Detected	Not specified

Diagnosis and Trigger Conditions

The technical background for these DTCs points to an internal defect within the EVAP leak detection pump (GX36). This defect can cause the system to falsely detect a leak, triggering the MIL and storing the associated fault codes, such as the Audi Q8 EVAP leak P044200.

Audi has introduced an optimized version of the GX36 pump in Model Year 2022 vehicles to address this issue. However, it is crucial to note that this optimized GX36 pump is not backward compatible with earlier model years.

Important Warnings

Technicians are specifically advised: Do not install the MY22 GX36 into older vehicles. This optimized component is designed only for MY22 and newer vehicles and will not function correctly in previous model years.

Repair Procedure Summary

The repair procedure for the Audi Q8 EVAP leak P044200 and P045600 involves a two-step process:

1. Confirm No Other Leaks: Before replacing any components, the technician must thoroughly confirm that no other leaks are present in the EVAP system. If another component is causing the fault code, this TSB does not apply, and that component should be addressed instead.
2. Replace EVAP LD Pump GX36: If no other failures are found after thorough inspection, the EVAP leak detection pump (GX36) should be replaced. This directly addresses the internal defect identified in the technical background.

Required Tools or Parts

For this repair, technicians will need the following:

• LD Pump (DMTL): Refer to ETKA for the VIN-specific part number. This is the replacement EVAP leak detection pump.
• Fasteners, Bolts, Nuts, and Screws: As needed per the Repair Manual, available via ETKA/ELSA.
• VAS 6160/VAS 6150: Diagnostic testers with the current version of ODIS (Windows 10) are required for checking and clearing fault codes and for performing leak diagnosis pump checks.

Warranty Information

Warranty claims for this repair are covered under specific conditions:

• Standard Warranty: Up to 48 months or 50,000 miles.
• CPO Covered Vehicles: For Certified Pre-Owned vehicles, the claim type is G10, and owner verification is required.
• Out-of-Warranty: If the vehicle is outside of any applicable warranty, this Technical Service Bulletin is for informational purposes only, and the repair cost would typically be borne by the owner.

Service Number 2048 and Damage Code 0010 are used for warranty claims related to this issue. Specific labor operations include 'Leak diagnosis pump check' (2048 0100), 'Leak diagnosis pump removed and reinstall' (2048 XXXX), and 'Rear wheel housing liners removed and reinstall' (6676 1900). Diagnostic time (GFF - Checking and clearing fault codes) is included in existing labor operations.

All parts and service references provided in this TSB (2067287) are subject to change.

---

Source: NHTSA ID: 10220368