A/C Signal: Description and Operation

A/C Request Signal
This signal tells the ECM when the A/C mode is selected at the A/C control head. The ECM 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 ECM.

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