A/C Signal: Description and Operation

PURPOSE
The A/C signal is an input to the Powertrain Control Module (PCM) which informs it that the A/C clutch has been energized. The PCM adjusts the idle speed and air/fuel mixture to compensate for the increased engine load.
OPERATION
With the A/C demand switch closed and both the cycling pressure switch and the high pressure cutout switch shut, battery voltage will be supplied to circuit ACC (10) informing the PCM the A/C clutch is energized.

RELATED DIAGNOSTIC TROUBLE CODES

DTC 539 - A/C request during self test procedure.

DTC 559 - A/C ON circuit failure.