Diagnosis

DTC P0530, P0560, P1639, or P1641 can affect A/C operation. Refer to the DTC tables if any DTCs are set.

The PCM Controlled Air Conditioning Diagnosis table diagnoses the electrical portion of the A/C compressor clutch circuit. To diagnose the refrigerant portion of the HVAC system, refer to the Heater, Ventilation, and Air Conditioning (HVAC) section. A scan tool will be used in diagnosing the system. The scan tool displays the A/C request and refrigerant pressure inputs to the PCM. The scan tool displays the PCM commanded state of the A/C clutch. The scan tool can override the A/C request signal and energize the A/C control relay.