Symptoms

- Engine Light ON (or Service Engine Soon Warning Light)

Possible Causes

- Open or short air condition clutch relay circuit - Poor air condition clutch relay electrical connection - Failed air condition clutch relay

When Detected

Code P0646 may be stored if the commanded signal from the AC Clutch circuit does not match the feedback signal.

Description

A/C clutch relay may also be referred to as A/C compressor clutch relay. A/C clutch relay circuit is monitored when ignition is on and battery voltage is greater than 10.4 volts.