A/C Signal: Description and Operation
PURPOSESignals ECU when A/C is turned ON. ECU then activates the idle-up solenoid valve to compensate for increased engine load by raising idle speed.
LOCATION
Idle-up solenoid is on the firewall near the brake master cylinder. Idle-up actuator is on the carburetor, near choke linkages.
OPERATION
When activated by the ECU, the idle-up solenoid valve directs vacuum to the idle-up actuator, causing it to open the throttle slightly and raise idle speed.