A/C Signal: Testing and Inspection

DIAGNOSIS
A scan tool will be used in diagnosing the system. The scan tool has the ability to display the A/C request and refrigerant pressure inputs to the PCM. The scan tool can display when the PCM has commanded the A/C clutch ON. The scan tool also has the ability to override the A/C request signal and energize the A/C control relay. To diagnose the refrigerant portion of the HVAC system, refer to Heating and Air Conditioning.