A/C - Doesn't Cool or Insufficient Performance
87 Air conditioning does not cool87 11 17
2024825/1
February 16, 2011.
AFFECTED VEHICLES
CONDITION
Air conditioning does not work or the cooling performance is insufficient.
TECHNICAL BACKGROUND
The control valve N 280 in the Sanden air conditioning compressor can fail, thus causing a condition where no cooling is provided by the A/C system. Only compressors with part number 1K0 820 859 F are affected. The affected compressors were only used in production for the 2009 MY A3 vehicles with the 3.2L engine. The blower functions normally during this condition.
PRODUCTION SOLUTION
Optimized Sanden air conditioning compressors were put into production.
SERVICE
Before replacing the Sanden air conditioning compressor, perform following checks.
1. Check the control valve according to the repair manual. (See Heating, Ventilation and Air Conditioning >> 87 Air Conditioning >> Diagnosis and Testing >> A/C Compressor Regulator Valve, Checking Switch-On Signal.)
2. Verify the refrigerant circuit has the correct refrigerant volume and refrigerant oil as specified by the repair manual.
Refrigerant: Heating, Ventilation and Air Conditioning >> Refrigerant R134a Servicing >> 00 General, Technical data >> Specifications >> Refrigerant R134a Capacities >> Capacities, Audi A3 (8P_) from MY 2004
Refrigerant Oil: Heating, Ventilation and Air Conditioning >> Refrigerant R134a Servicing >> 00 General, Technical data >> Specifications >> Refrigerant Oil Capacities >> Capacities, Audi A3 (8P_) from MY 2004
^ If the system charge is low then check for leaks and repair as necessary. If a leak is found then do not replace the compressor.
^ If the system charge is too high then it's possible the evaporator is freezing up causing reduced cooling performance. Refilling the system to the correct amount can improve the A/C performance if the system was overcharged. If this is the case then do not replace the compressor.
3. Refill the system and check the pressure in the refrigerant circuit using the following method.
a. Switch the engine on in a warm environment. (Too cool of an environment will disable the compressor from activating by the climate control software.)
b. Set the air conditioning to "64°F & Auto".
c. Check the pressure before the compressor intake and document the value.
d. Check the pressure in the high pressure section and document the value.
e. If both values are approximately the same, replace the air conditioning compressor.
WARRANTY INFORMATION
REQUIRED PARTS AND TOOLS
ADDITIONAL INFORMATION
All parts and service references provided in this TSB are subject to change and/or removal. Always check with your Parts Department and service manuals for the latest information.