2021-2022 Audi AC Not Cooling P053000 P251500

Symptoms of AC Not Cooling

Owners of 2021-2022 Audi vehicles may experience their air conditioning system failing to cool the cabin. This condition can be intermittent, meaning the AC might work sometimes and not others. If your Audi AC not cooling, it's important to have it checked.

Diagnostic Trouble Codes (DTCs)

When the air conditioning system fails to cool, technicians may find one or both of the following Diagnostic Trouble Codes (DTCs) stored in the Thermal Management control unit (J1024, address word 00C5):

Code	Description	Module
P053000	Air conditioning system pressure sensor electrical fault	Thermal management J1024
P251500	Refrigerant pressure sensor 2 electrical fault	Thermal management J1024

These codes specifically point to electrical issues with the pressure sensors responsible for monitoring the refrigerant system.

Technical Background

The root cause of the Audi AC not cooling issue is a failure within the electronics of certain pressure sensors. Specifically, sensors with the base part number 4M0959603 and a manufacturing build date before Calendar Week 31 of 2021 are prone to this failure. These faulty sensors, identified as G395 and G827, lead to an inaccurate or complete loss of pressure evaluation within the AC system, preventing proper cooling.

Audi has since implemented an improved sensor design in production to address this defect.

Diagnosis and Repair Procedure Summary

To diagnose and resolve the Audi AC not cooling problem, technicians will follow a specific procedure:

1. Sensor Inspection: If a vehicle presents with the described symptoms and DTCs, all pressure sensors in the refrigerant circuit with base part number 4M0959603 and a build date before Calendar Week 31, 2021, must be inspected and potentially replaced. Depending on the specific model, there can be one to three such sensors installed in various positions, on either the low or high-pressure sides of the circuit.
2. Marking Verification: Technicians will inspect the markings on the sensor to determine if it has already been replaced with an improved version. While a green dot on the connector housing was an initial indicator of an improved sensor, it is not always present on newer, improved parts. The conclusive method is to check the sensor's build date and laser marking on the aluminum housing. Sensors with an 'E' index, produced after Calendar Week 31, 2021, and featuring a laser marking, are considered improved and do not require replacement.

The repair involves removing and reinstalling the pressure switches and then draining and refilling the refrigerant.

Required Parts

The primary component required for this repair is an updated pressure and temperature sensor. The part number is:

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

Always consult with your Audi Parts Department for the latest information and part bulletins.

Warranty Information

This Technical Service Bulletin outlines warranty coverage for the repair. Claims are generally covered for vehicles up to 48 months or 50,000 miles. For Audi Certified Pre-Owned (CPO) vehicles, coverage is under claim type G10, requiring owner verification. If the vehicle falls outside these warranty parameters, the bulletin serves as informational guidance.

The Service Number for this procedure is 8757, and the Damage Code is 0040. Specific labor operations are detailed for various models, including A6/A7, Q7/Q8, A8 (PHEV and non-PHEV), e-tron GT, Q5, and e-tron models. These operations include tasks such as removing and reinstalling pressure switches and draining and refilling the refrigerant system.

Revision History

This bulletin, 2068460/4, supersedes Technical Service Bulletin Group 87 number 23-40 dated April 10, 2023. Key revisions include:

• Revision 4 (August 10, 2023): Revised service instructions, specifically changing the statement concerning sensor marking.
• Revision 3 (April 11, 2023): Revised warranty information with a correction for e-tron SRT.
• Revision 2 (January 31, 2023): Revised warranty information, changing the maximum time allowed for GFF (Guided Fault Finding).

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NHTSA ID: 10241432