The A/C system uses a scroll type compressor controlled by the PCM to meet the cooling demands. The A/C clutch system consists of the following components:

When an A/C mode is selected, the IPM sends a Class 2 message to the DIM. The DIM then checks the A/C pressure sensor, the low side temperature, the engine coolant temperature, and the system voltage. If all the conditions are right to allow compressor operation, the DIM sends an A/C request signal via Class 2 to the PCM. The PCM energizes the A/C relay coil by grounding the A/C relay control circuit. This closes the relay contacts and applies a fused battery voltage to the A/C compressor clutch. The PCM enables the compressor clutch whenever the engine is running and A/C is requested unless one or more of the following conditions are present:

PCM DTCs P0532, P0533, P0560, P0562, P0563, P1545 and P1639 affect the A/C operation. Refer to the appropriate DTC tables to diagnose any PCM set DTCs. The HVAC system may contain DTCs that also affect the A/C operation. Refer to the appropriate DTC table in Heater, Ventilation, and Air Conditioning to diagnose any HVAC DTCs.

The PCM controlled air conditioning table diagnoses the electrical portion of the A/C compressor clutch circuit when no DTC is set. To diagnose the refrigerant portion of the HVAC system, refer to Heater, Ventilation, and Air Conditioning (HVAC). A scan tool will be used in diagnosing the system. The scan tool has the following functions to aid diagnosis: