A/C Signal: Description and Operation

This signal tells the PCM when the A/C mode is selected at the A/C control head. The PCM uses this to adjust the idle speed before turning ON the A/C clutch. The A/C compressor will be inoperative if this signal is not available to the PCM.

Refer to A/C Clutch Circuit Diagnosis for A/C wiring diagrams and diagnosis for the A/C electrical system.

Compressor HVAC