Audi Workshop Service and Repair Manuals

Test requirements

• ◆ Radiator and condenser are both clean (clean if necessary).
• ◆ The ribbed belt is OK and properly tensioned.
• ◆ All air ducts, covers and seals are OK and correctly fitted.
• ◆ Air flow through dust and pollen filter is not impeded by dirt.
• ◆ The air conditioner is free of leaks (no secondary air drawn in at high fresh air blower speeds - air escapes through vents only).
• ◆ Vehicle is not exposed to sunlight.
• ◆ The heat insulation for the expansion valve is OK and properly fitted.

• ◆ The engine is at operating temperature.
• ◆ All dash panel vents are open.
• ◆ With the engine running and operating and display unit -E87 set at:
• ‒ "Auto" mode
• ‒ Compressor switched on (compressor symbol "frost symbol" lights up on left display or warning lamp in "ECON"- key does not light up).
• ‒ "LO" temperature selected

• ‒ If the compressor is driven (air conditioner magnetic clutch is engaged):
• ‒ Actuation of radiator fan -V7:
• ‒ in vehicles with pressure switch -F129 (at least at speed 1).
• ‒ in vehicles with high pressure sensor -G65 (at speed 1 or is switched on during refrigerant performance check).

Notes:

• ◆ Radiator fan control unit -J293 versions and vehicle wiring differ for vehicles with pressure switch -F129 and high-pressure sensor -G65.

=> Parts List

=> Current Flow Diagrams, Electrical Fault-Finding and Fitting Locations

• ◆ Control unit -J293, installed in vehicles with high-pressure sensor -G65, is available in 2 designs.
• ‒ In design "1" the radiator fan is automatically switched on in conjunction with the compressor (the first fan speed is activated regardless of the pressure in the refrigerant circuit).
• ‒ In design "2" the compressor is switched on without the radiator fan; the first fan speed is only activated once the pressure in the refrigerant circuit has exceeded 12 bar.

• ‒ Fresh air blower -V2 runs at maximum speed.
• ‒ The fresh/recirculated air flap switches to "recirculated-air" position (within 1 min. after vehicle start-up).

• ‒ Air blows out of the dash panel vents.
• ‒ Temperature flap is in the "cooling" position.

Note:

If one of the test requirements is not fulfilled, interrogate fault memory and perform final control diagnosis ().

Preparatory work:

• ‒ Interrogate fault memory and locate and rectify any faults displayed ().
• ‒ Perform basic setting and check coding ().
• ‒ Close bonnet and sliding roof.
• ‒ Measure ambient temperature.
• ‒ Close doors and windows.

Checking:

• ‒ Switch ignition on.
• ‒ Set operating and display unit -E87 for "auto" mode and "LO" temperature selection.
• ‒ Start engine (compressor is driven).
• ‒ Actuate button for recirculated-air flap (symbol for "recirculated air" in the right display illuminates).
• ‒ Increase the engine speed to 2000 rpm (start of time measurement).
• ‒ Measure air temperature from the "centre" dash panel vents.

→ Compare measured values with chart.

• ‒ A - Air temperature from the "centre" dash panel vents.
• ‒ B - Measured ambient temperature.
• ‒ C - Permissible temperature range for the vent temperature.

• ‒ → The temperature of the air emanating from the centre dash panel vents must be within tolerance -C- in the chart after 5 minutes (will vary according to the ambient temperature).

Note:

If the required values are not attained (determine fault if specified value not attained).

Fault determination in the event of deviation from specified value

Continuation from Page 87-94 (compressor was deactivated during the refrigeration capacity test).

Continued from page 87-95 (compressor shut-off criterion code "1" for vehicles with pressure switch -F129).