Compressor Clutch Relay: Description and Operation

A/C Refrigerant Pressure Sensor Circuit:

Quad-Driver Module (QDM 2) Circuit:

Purpose
The PCM utilizes the A/C relay by supplying the ground signal to the coil side of the relay. The magnetic field, generated by electricity flowing through the coil, closes the switch within the relay allowing current flow to the A/C compressor.

Operation
The A/C control relay is controlled by the PCM so the PCM can increase idle speed before turning "ON" the clutch and can disable the clutch during wide open throttle (WOT), high RPM or during hot engine restarts. The PCM also disables the clutch if the coolant temperature exceeds 125°C.

Location
The A/C relay is located on the relay bracket on the right side of the engine compartment.