A/C Signal: Description and Operation

A/C CUTOFF SYSTEM DESCRIPTION
- An A/C cutoff system is used to improve idle smoothness immediately after starting the engine and to improve acceleration and performance.

A/C SIGNAL
- If the A/C is on during the diagnostic trouble code check, a Diagnostic Trouble Code is output.
- If the circuit is open, wide open throttle A/C cutoff will not occur.
- If the circuit is shorted, the A/C will not operate.

WIDE OPEN THROTTLE A/C CUT-OFF (WAC) RELAY
Disengages A/C clutch during the following conditions:
- Engine cranking
- Engine overheated
- Wide open throttle




Operation
The relay is normally closed. When A/C switch is turned on, and A/C cycling switch and A/C pressure switch are closed, voltage is supplied to relay and PCM. PCM will then verify that A/C clutch operation is desirable. PCM controls as follows:
- If desirable: Adjust idle speed and unground relay
- If not desirable: Ground relay.