Faulty A/C Demand Switch
Faulty Wide Open Throttle A/C Cutoff (WAC) Relay
Wide Open Throttle A/C Cutoff Relay harness is open or shorted
Wide Open Throttle A/C Cutoff Relay circuit poor electrical connection
Faulty Powertrain Control Module (PCM)
Engine Light ON (or Service Engine Soon Warning Light)
The Diagnostic Trouble Code (DTC) P1464 can be set if A/C or defroster is on during Key On Engine Off (KOEO) or Key On Engine Running (KOER) self-test. The DTC P1464 is set when ACCS input to Powertrain Control Module (PCM) was high during self-test.