Compressor Clutch Does Not Engage

HVAC Compressor Clutch Does Not Engage

Test Description

Step 1 - Step 8:

Step 9 - Step 21:

Step 22 - Step 37:

Step 38 - Step 39:

The numbers below refer to the step numbers on the diagnostic table.
2. The A/C compressor relay output is disabled if engine coolant temperature is above 123°C (253°F). The instrument panel engine coolant gage will indicate overheating.
3. Place the mode switch in any position except OFF, and place the air temperature control switch in a cold setting. Use the believe mode for consistent testing of the A/C system operation.
6. The HVAC control module is inoperative if the module does not respond to any operator control requests.
14. Be sure to verify the engine control module (ECM) or powertrain control module (PCM) engine grounds are secure and clean.