87 Air Conditioning System: Cooling Output Insufficient, Leak On Air Conditioning System Evaporator (GROUP 87, NO. 25-98)

87 AIR CONDITIONING SYSTEM: COOLING OUTPUT INSUFFICIENT, LEAK ON AIR CONDITIONING SYSTEM EVAPORATOR

TECHNICAL SERVICE BULLETIN

SERVICE INFORMATION

87 25 98 2064077/6 January 23, 2025. Supersedes Technical Service Bulletin Group 87 number 24-81 dated July 27, 2024 for reasons listed below.

CONDITION

Customer states: 

• The air conditioning does not cool the interior.
• The cooling output of the air conditioning system is insufficient.

Workshop findings: 

• The customer statement can be reproduced.
• The refrigerant circuit is not filled with the required amount of refrigerant.

TECHNICAL BACKGROUND 1

1. An insufficient amount of refrigerant is usually caused by leaks in the refrigerant circuit.

   On the vehicles listed in this TSB, the evaporator of the air conditioning system is a potential source of a leak. It is fitted in the air conditioning unit and is not easily accessible from outside (Figure 1).

2. Without direct access to the evaporator, the following are possible ways to detect a leak in the evaporator:
3. Electronic leak detector: 

   Check whether the electronic leak detector finds refrigerant on the center vents (Figure 2). To do this, select the following air conditioner settings: Blower on lowest level and air distribution set to dash panel vents.

4. Leak detection additive:

   If a leak detection additive is put into the refrigerant circuit, deposits of the additive will appear on the condensation drain after the air conditioner has been operated at high load for a sufficient time (Figure 3).

5. You can also check this on the vehicle's underbody (Figure 4).
6. Leak test for refrigerant circuits R134a, R1234yf and R744 with forming gas (calibration gas): 

   For further information on the exact procedure and the tools required to carry out the leak test, please refer to the Training module ATP 611 05_2022: SoST - Leak test on the refrigerant circuit R134a, R1234yf and R744 in the Audi Knowledge Tank (AKT).

7. WARNING: For vehicles with refrigerant R744 only the "Leak test with forming gas" method is allowed.
8. NOTE: Should the evaporator for the Q5 be confirmed leaking by way of this diagnostic procedure and replacement of the evaporator is performed it is necessary to loosen and refasten the Relay and Fuse Carrier 3 - SR3- (shown in figure 5, position 1) in the course of the repair. During reassembly of the vehicle, it is critically important  that this relay and fuse carrier is reinstalled in its correct original position. Failure to reinstall the Relay and Fuse Carrier 3 precisely will result in water intrusion and subsequent component damage.

PRODUCTION SOLUTION

Gradual introduction of optimized production process in series production.

SERVICE

If a leak is determined on the evaporator, replace the evaporator.

When billing, please always attach photos/videos that clearly shows the complaint to DOC-IT. To ensure a reference to the vehicle, the image/video must:

• Include the VIN and date.
• Must not be edited.
• Should be in focus and taken with sufficient light. A high resolution is not necessary.

If appropriate, please mark the location of the problem so that parts analysis has a clear reference to the complaint. Please ensue that the photo documentation does not show any persons and/or face, license plates, or customer data.

WARRANTY

All warranty claims submitted for payment must be in accordance with the Audi Warranty Policies and Procedures Manual  . Claims are subject to review or audit by Audi Warranty.

ADDITIONAL INFORMATION

All part and service references provided in this TSB (2064077  ) are subject to change and/or removal. Always check with your Parts Department and/or ETKA for the latest information and parts bulletins. Please check the Repair Manual for fasteners, bolts, nuts, and screws that require replacement during the repair.

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