2020-2022 Audi AC Not Cooling: DTCs P053000, P251500

Audi has issued Technical Service Bulletin (TSB) 2068460/6 to address a condition where the "Air conditioning does not cool" in various 2020-2022 Audi models. This issue is typically accompanied by specific diagnostic trouble codes (DTCs) related to the air conditioning system's pressure sensors. Owners experiencing this problem, such as an Audi e-tron air conditioning not cooling, should be aware of the potential causes and recommended solutions.

This TSB, released on May 10, 2024, supersedes previous bulletin 23-55 dated October 2, 2023. It provides updated guidance for diagnosing and repairing the air conditioning system.

Symptoms

Owners of affected Audi vehicles may observe that the "Air conditioning does not cool" the cabin effectively. This cooling issue can sometimes be intermittent, making it difficult to pinpoint the exact problem without proper diagnosis.

Fault Codes / DTCs

When the air conditioning system is not cooling, one or both of the following Diagnostic Trouble Codes (DTCs) may be stored in the Thermal management control unit, J1024 (address word 00C5):

Code	Description
P053000	Air conditioning system pressure sensor electrical fault
P251500	Refrigerant pressure sensor 2 electrical fault

These codes specifically point to electrical faults within the pressure sensors responsible for monitoring the refrigerant circuit.

Technical Background

The root cause of the Audi e-tron air conditioning not cooling and the associated DTCs is often a failure in the sensor electronics. This failure leads to an inaccurate or complete loss of pressure evaluation within the air conditioning system. The specific sensors at issue are those with base part number 4M0959603 and a manufacturing build date before Calendar Week 31, 2021. These sensors are identified as G395 and G826 within the system.

Audi has since implemented an improved sensor design in production to prevent this issue in newer vehicles.

Diagnosis and Repair Procedure Summary

For vehicles presenting with the symptoms and DTCs described in TSB 2068460/6, technicians are instructed to inspect and potentially replace the affected pressure sensors. The general repair process involves:

1. Sensor Inspection: Identify all pressure sensors in the refrigerant circuit with the base part number 4M0959603. Vehicles may have between one and three of these sensors installed in various positions.
2. Build Date Verification: Determine the build date of each sensor. Sensors manufactured before Calendar Week 31, 2021, are the ones prone to failure.
3. Improved Sensor Identification: Check for markings on the sensor that indicate it is an improved type. While some improved sensors may have a green dot on the connector housing, this is not the sole indicator. A laser marking on the aluminum housing, particularly for 'E' index sensors produced after Calendar Week 31, 2021, confirms it is the improved type and does not require replacement.
4. Replacement: If a sensor is identified as the older, faulty type, it must be replaced. All sensors being replaced must be of the same part number index (e.g., all 'E' index or all 'J' index) to avoid LIN communication conflicts.

Important Warnings

Audi has provided critical notices regarding the identification and replacement of these sensors:

• "The presence of the green dot on the sensor is not the sole, conclusive evidence of the sensor being of the improved type. The green dot was applied in production as an immediate identification of an improved sensor, but the green dot was not applied indefinitely. Always check the sensor date as this is the confirmation of the sensor status."
• "Pressure sensors with different part number indexes are not interchangeable. When replacing the pressure sensors, all of the sensors being replaced must be of the same part number index (e.g., all sensors must be 'E' index, or all sensors must be 'J' index). LIN communication conflict will result if differing part indexes are used."

Required Parts

The primary part required for this repair is the improved pressure and temperature sensor. The part number is:

• 4M0959603E: Pressure and temperature sensor (Quantity: 1-3)

Always confirm the latest part information with your Audi Parts Department or ETKA.

Warranty Information

This repair may be covered under warranty depending on the vehicle's age and mileage. The claim types include:

• Standard warranty: Up to 48 months or 50,000 miles.
• Certified Pre-Owned (CPO) vehicles: G10 claim type, requiring owner verification.

If your vehicle is outside of these warranty periods, this Technical Service Bulletin serves as informational guidance. The Service Number for this repair is 8757, with a Damage Code of 0040. All warranty claims must adhere to the Audi Warranty Policies and Procedures Manual, and claims are subject to review.

NHTSA ID: 11002247