2021-2023 Audi MIL On: False EVAP Leak DTC P044200, P045600

Audi has issued Technical Service Bulletin (TSB) 2065287/6 to address a common issue affecting various 2021-2023 Audi models. This bulletin, which supersedes TSB 22-51 dated October 27, 2022, provides updated information and service instructions for diagnosing and resolving instances where the Malfunction Indicator Lamp (MIL) illuminates due to specific EVAP system fault codes.

This issue primarily affects the EVAP (Evaporative Emission Control) system, which is crucial for preventing fuel vapors from escaping into the atmosphere. When the system's leak detection pump (GX36) is overly sensitive, it can trigger false warnings, even when no actual leak is present.

Symptoms

Owners of affected Audi vehicles may notice the following symptom:

• The "MIL on" (Malfunction Indicator Lamp) illuminates on the dashboard.

This warning light indicates that the engine control module (ECM) has detected a potential issue within the vehicle's emission system, prompting the need for diagnosis.

Fault Codes / DTCs

When the MIL is illuminated for this condition, diagnostic scans of the engine control module (ECM), identified as J623, may reveal one or both of the following diagnostic trouble codes (DTCs):

Code	Description	Symptom Code
P044200	EVAP Emissions Control System (Small Leak) Detected	11955
P045600	EVAP Emissions Control System (Very Small Leak) Leak Detected	N/A

These codes specifically point to a detected leak within the EVAP system, which, in this case, may be a false detection.

Diagnosis and Cause

The root cause of the illuminated MIL and the stored DTC P044200 or P045600 is an overly sensitive calibration of the EVAP leak detection pump (GX36). This sensitivity can lead the system to erroneously detect a leak in the EVAP system, even when none exists. Audi has implemented an optimized GX36 pump in newer MY22 vehicles as a production solution to this issue.

Important Warnings

Owners and technicians should be aware of a critical compatibility warning regarding the EVAP leak detection pump:

• The optimized GX36 is not backward compatible with previous model years. Do not install the MY22 GX36 into older vehicles.

This means that the newer, optimized pump designed for MY22 and later vehicles cannot be used as a replacement in earlier models. Using an incompatible part will not resolve the issue and could potentially cause further problems.

Repair Procedure Summary

For affected 2021-2023 Audi vehicles displaying the "MIL on" with DTC P044200 or P045600, the repair procedure outlined in TSB 2065287/6 involves a series of diagnostic steps followed by a potential component replacement:

1. Confirm No External Leaks: Technicians must first thoroughly inspect the EVAP system to ensure no actual leaks are present from other components. If a physical leak is found, this TSB does not apply, and the leak must be repaired separately.
2. Check Fault History: The vehicle's fault history should be reviewed using the GFF paperless system. If the fault codes P044200 or P045600 have not been previously stored, the technician should clear the fault codes and release the vehicle.
3. Replace EVAP LD Pump GX36: If the fault has been previously set, or if it is a static fault and no other system failures are identified, the EVAP Leak Detection Pump (GX36) should be replaced. This addresses the overly sensitive calibration that triggers the false EVAP system P044200 or P045600 codes.

Required Tools and Parts

To perform the repair, technicians will require specific tools and parts:

• LD Pump (DMTL): A VIN-specific Leak Detection Pump (DMTL) must be ordered using the Electronic Parts Catalog (ETKA).
• Fasteners: Any necessary fasteners, bolts, nuts, and screws should be obtained according to the repair manual and ETKA/ELSA.
• VAS Tester: A VAS tester, such as VAS 6160 or VAS 6150, with the current version of ODIS (Windows 10) is required for diagnosis and programming.

Warranty Information

This repair is typically covered under Audi's warranty for up to 48 months or 50,000 miles, whichever comes first. For Audi Certified Pre-Owned (CPO) vehicles, coverage falls under the G10 claim type, requiring owner verification. If the vehicle is outside of its warranty period, this Technical Service Bulletin serves as informational guidance, and the repair costs would generally be the owner's responsibility. The service number for this repair is 2048, with a damage code of 0010.

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Source: NHTSA ID: 10230589