Operation CHARM: Car repair manuals for everyone.

A/C Request Signal

DESCRIPTION
This signal tells the Powertrain Control Module (PCM) that the air conditioning selector switch is turned "ON," and that the A/C refrigerant pressure switch is closed. The PCM uses this to adjust the idle speed before turning "ON" the A/C clutch.

If this signal is not available to the PCM, the A/C compressor will be inoperative.