2021-2022 Audi A/C Not Cooling: DTC P053000, P251500 TSB

Owners of various 2021-2022 Audi models, including the Audi e-tron, A6, A7, Q5, Q7, Q8, S6, S7, S8, SQ5, SQ7, SQ8, RS6, RS7, RS Q8, A6 allroad, A8 L e, e-tron GT, and RS e-tron GT, may experience issues with their air conditioning system not cooling the cabin. This condition can be intermittent and is often accompanied by specific diagnostic trouble codes (DTCs).

This Technical Service Bulletin (TSB 2068460/5), superseding TSB 23-50 dated August 10, 2023, provides detailed information for diagnosing and resolving this A/C performance problem. It outlines a procedure for identifying and replacing defective refrigerant pressure sensors.

Symptoms

Owners may notice that the air conditioning system does not cool the cabin effectively. This lack of cooling can be inconsistent, appearing intermittently rather than constantly.

Fault Codes / DTCs

When diagnosing the issue, technicians may find one or both of the following DTCs 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

Technical Background

The root cause of the air conditioning not cooling is often a failure within the sensor electronics of the refrigerant pressure sensors. This electronic malfunction leads to a loss of accurate pressure evaluation within the A/C system. The specific sensors at fault are those with base part number 4M0959603 and a build date before Calendar Week 31, 2021. These sensors are identified as G395 and G826 within the system.

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

Diagnosis and Trigger Conditions

To diagnose the issue and confirm the need for repair, technicians must inspect the refrigerant pressure sensors in the vehicle. The primary diagnostic step involves checking the build date of the installed sensors.

Sensors with base part number 4M0959603 and a build date before Calendar Week 31, 2021, are considered problematic and require replacement. Technicians will inspect markings on the sensor to determine its build date. While some improved sensors may have a green dot on the connector housing, this is not a definitive indicator. The laser marking on the aluminum housing, which indicates the build date, is the crucial piece of information. A sensor with an 'E' index, produced after Calendar Week 31, 2021, is of the improved type and does not need replacement.

Repair Procedure Summary

The repair procedure involves inspecting and, if necessary, replacing the faulty refrigerant pressure sensors. Each affected Audi model will have between one and three of these sensors installed in various positions within the refrigerant circuit, on either the low or high-pressure sides.

1. Inspect Sensors: Technicians will visually inspect all pressure sensors in the refrigerant circuit with base part number 4M0959603. They will check the laser markings on the sensor's aluminum housing to determine the build date. Sensors produced before Calendar Week 31, 2021, are candidates for replacement.
2. Replace Sensors: Any identified faulty sensors (those with the older build date) will be replaced with the updated part. This process requires draining the refrigerant from the A/C system and then refilling it after the new sensors are installed.

Required Parts

To address the Audi e-tron A/C not cooling P053000 and P251500 issues, the following part is required:

Part Number	Part Description	Quantity
4M0959603E	Pressure and temperature sensor	1-3

Technicians should always verify the latest part information with the parts department.

Warranty Information

This repair is covered under warranty for qualifying vehicles. The claim type is typically 110 for vehicles up to 48 months/50,000 miles. For CPO (Certified Pre-Owned) vehicles, G10 is used, requiring owner verification. The service number for this bulletin is 8757, and the damage code is 0040. Labor operations involve refrigerant drain and fill (8703 1700) and pressure switch removal and reinstallation (e.g., 8709 2050, 8757 2093, 8757 1950, 8764 1950, 8709 2051, depending on the model and specific sensor).

Important Warning: If the vehicle is outside any warranty, this Technical Service Bulletin is informational only, meaning the repair costs would typically be the owner's responsibility.

Owner Action

If you own a 2021-2022 Audi and are experiencing your air conditioning not cooling, especially if you suspect an Audi e-tron A/C not cooling P053000 issue, it is recommended to schedule an appointment with an authorized Audi service center. They can perform a diagnostic scan to confirm the presence of DTCs P053000 or P251500 and inspect the refrigerant pressure sensors according to this TSB.

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Source: NHTSA ID: 10243955