Possible Complaints

WARNING: This page is about a different car, the 2023 Audi SQ8, 2023 Audi RS Q8, and 2023 Audi Q8. However, it is still accessible from the selected car via links, so may be relevant.

NOTE:

All complaints marked with *. Refer to PRESSURES, CHECKING "Checking pressures".

If a malfunction occurs at only one evaporator in vehicles with two evaporators, also check the pressures in the refrigerant circuit.

Observe the test requirements. Refer to TEST PREREQUISITES .

Vehicles without High-Voltage System

Total cooling system failure.*
Insufficient cooling output at all vehicles speeds or engine speeds.*
None or insufficient cooling after driving a few miles. *
No or insufficient cooling at one or both evaporators (for vehicles with two A/C units). *
The A/C compressor, A/C Clutch -N25- or A/C Compressor Regulator Valve -N280- are shut off by a pressure switch (for example, A/C Refrigerant Low Pressure Switch -F73-, Magnetic Clutch High Pressure Switch -F118-, A/C Pressure Switch -F129- or by the Front A/C Display Control Head -E87- or Climatronic Control Module -J255-) due to excessive or inadequate pressure. * Refer to Refrigerant Circuit (vehicle-specific service information).
None or sharp decrease in fresh-air supply after driving several miles (evaporator iced up). *

Vehicles with High-Voltage System

Total cooling system failure.*
Insufficient cooling output at all vehicles speeds or A/C compressor speeds.*
None or insufficient cooling after driving a few miles. *
No or insufficient cooling in the evaporator or on a heat exchanger (for example on the high-voltage battery heat exchanger). * Refer to Refrigerant Circuit (vehicle-specific service information).
No or insufficient heating output at the heat exchanger for the heat pump operation (for example on the Audi Q7 e-tron)*. Refer to Refrigerant Circuit (vehicle-specific service information).
The Electrical A/C Compressor -V470- is switched off by a control module (for example Front A/C Display Control Head -E87-, Climatronic Control Module -J255- or Thermal Management Control Module -J1024-) due to excessive or inadequate pressure. * Use the Vehicle Diagnostic Tester in the "Guided Fault Finding" function
None or sharp decrease in fresh-air supply after driving several miles (evaporator iced up). *

All Vehicles

From these, the following complaints may also occur:

The A/C compressor makes noises

-- Tighten the compressor securing bolts and compressor bracket using a torque wrench.

-- Check the routing of refrigerant pipes; they must not touch other components and must not be subject to strain (align if necessary).

Noise (refrigerant hammer) occurring immediately after switching on air conditioner and/or when cornering or braking

-- Discharge, evacuate and charge refrigerant circuit (too much refrigerant in circuit).

NOTE:

Too much refrigerant oil in the circuit could also cause this problem. This could occur if the amount of refrigerant oil was not adjusted when replacing the A/C compressor.

Water sprays out of vents (in dash panel or footwell) although air conditioning system is otherwise functioning properly:

-- Check proper routing of condensate drain; it must not be crushed or kinked.

-- Check condensation drain valve, it must not be clogged by wax or underbody sealant and must close properly.

-- Check the plenum chamber cover; it must not be damaged and must be properly installed (to stop water running into evaporator).

-- Check the water drains in plenum chamber; they must not be blocked (for example, by leaves).