Operation CHARM: Car repair manuals for everyone.

A/C Signal: Description and Operation

A/C Circuit:





PURPOSE
When received by the ECM, the A/C switch signal causes the ECM to make adjustments needed (such as raise idle speed) to compensate for the added load.

When the ECM recives a "full open" signal from the throttle position sensor while the A/C is operating, the A/C cut relay turns off the compressor for a certain period. This improves full-throttle acceleration.

LOCATION
The A/C switch is located in the HVAC control panel. The throttle position sensor is attached to the throttle body.