Cooling Output, Checking

Special tools and workshop equipment required 

• Digital Thermometer: VAS6519 

Test Requirements

• Ambient temperature greater than 15 °C (59 °F).
• Radiator and condenser are clean (clean if necessary).
• The ribbed belt, which drives the A/C compressor, is OK and tensioned correctly. The belt pulley is actually driving the A/C compressor (vehicles without a high-voltage system).
• All air ducts, covers and seals are OK and properly installed.
• Seal between the engine compartment, hood and plenum chamber is OK and installed correctly. Refer to Bulkhead ; (Overview - Plenum Chamber Cover) to check.
• The airflow through the dust and pollen filter is not obstructed by debris. Refer to DUST AND POLLEN FILTER, REMOVING AND INSTALLING to check.
• The heater and A/C unit air intake (in fresh air and recirculating air modes) is not obstructed by dirt or retrofitted components.
• Vehicles without glove compartment cooling: the glove compartment cooling connection is sealed on the heater and A/C unit.
• Vehicles with glove compartment cooling: glove compartment cooling connection is installed on the heater and A/C unit according to the specification.
• The vehicle is not exposed to sunlight.
• Engine at operating temperature: coolant temperature is greater than 80 °C (176 °F).
• The DTC memory for the A/C Control Module -J301- /Climatronic Control Module -J255- control head was checked and erased, basic setting performed and the A/C Control Module -J301- / Climatronic Control Module -J255- coding is checked using the Vehicle Diagnostic Tester in the Guided Fault Finding  function.
• A/C Control Module -J301- / Climatronic Control Module -J255- adaptation checked using the Vehicle Diagnostic Tester in the Guided Fault Finding  function.

Checking

-- Close the hood.

-- Measure the ambient temperature.

-- Close the doors, windows and sliding sunroof.

-- Open all instrument panel vents.

-- Set the A/C system temperature to the "coldest" setting.

-- Adjust the air distribution at the center vent.

-- Hold the temperature sensor -2- for the Digital Thermometer: VAS6519  approximately 20 mm into the displayed area -3- of the instrument panel vent -1-.

-- Press the AC  button and turn on the A/C system.

-- Start the engine.

-- Bring engine to approximately 2000 RPM and hold it there.

Evaluating

Courtesy of VOLKSWAGEN GROUP OF AMERICA, INC.

The temperature of the air coming out of the "driver side" instrument panel vents must be within the tolerance range (see diagram) after five minutes, depending on the ambient temperature.

A -  Temperature of the air coming out of the "driver side" instrument panel vents

B -  Ambient Temperature

C -  Permissible Tolerance Range