Test Description

WARNING: This page is about a different car, the 2002 GMC Sierra, 2002 GMC Cab & Chassis Sierra, 2002 Chevrolet Silverado, and 2002 Chevrolet Cab & Chassis Silverado. However, it is still accessible from the selected car via links, so may be relevant.

The numbers below refer to the step numbers on the diagnostic table.

2) - These actions will disable the HVAC control module output to powertrain control module (PCM).
3) - This step checks the A/C Request Signal parameter to see if the PCM is interpreting an A/C request.
4) - Ensure that both A/C request signal circuits of the A/C high pressure switch are tested for listed conditions.
5) - The A/C Request Signal parameter is Yes. The A/C request signal circuits both are not shorted to ground. This step verifies that the A/C high pressure switch is not shorted internally to ground.

Fig 1: HVAC Compressor Clutch Does Not Disengage Diagnosis (Steps 1-10)

Courtesy of GENERAL MOTORS CORP.

Fig 2: HVAC Compressor Clutch Does Not Disengage Diagnosis (Steps 11-17)

Courtesy of GENERAL MOTORS CORP.