DTC P0645: A/C Clutch Relay Circuit: Description
A/C clutch relay voltage is monitored with ignition on and battery voltage more than 10.4 volts. DTC will set in Powertrain Control Module (PCM) when PCM senses an open or short in A/C clutch relay control circuit. Possible causes for DTC to set are: defective A/C clutch relay, defective PCM, defective connector or defective wiring.