Air Conditioning (A/C) Clutch Status Circuit Diagnosis

Air Conditioning (A/C) Clutch Status Circuit Diagnosis

Refer to Engine Controls Schematics Air Conditioning .

Circuit Description

When the A/C control switch is turned ON and the A/C compressor relay is energized, voltage should be present at both the A/C compressor clutch and the A/C clutch status circuit at the powertrain control module (PCM). The PCM does not control the A/C compressor clutch. The PCM monitors the operation of the A/C compressor clutch through the A/C Status circuit. The PCM uses this information in order to compensate for the engine load changes, caused by the A/C system, by adjusting the ignition timing and the throttle angle.

Test Description

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

Important: In order to properly diagnose the A/C system, the outside temperature must be above 16°C (60°F).


2. This step checks the operation of the A/C compressor clutch.
8. This verifies that the A/C Status circuit has been repaired and that the PCM has the ability to determine that the A/C compressor clutch is engaged.