Operation CHARM: Car repair manuals for everyone.

Air Conditioning Switch: Description and Operation

A/C Switch

PURPOSE
Provides a signal to the EFC control unit (ECU) that A/C operation is requested.

LOCATION
A/C switch is on the HVAC control panel.

OPERATION
When the A/C switch is turned on, it supplies a ground signal to the ECU. The ECU will then supply the ground circuit for the A/C relay and the fast idle control device (FICD) solenoid. The FICD raises the engine idle and the A/C relay engages the compressor clutch.