DTC P0645: Air Conditioning Clutch Relay (A/CCR) Primary Circuit Malfunction (Also Referred to as WAC Circuit)
WARNING: This page does not describe the selected car, but rather 32 other vehicles, including the 2005 Mercury Sable, 2005 Mercury Mountaineer, 2005 Mercury Monterey, 2005 Mercury Montego, and 2005 Mercury Mariner. However, it is still accessible from the selected car via links, so may be relevant.
P0645 - AIR CONDITIONING CLUTCH RELAY (A/CCR) PRIMARY CIRCUIT MALFUNCTION (ALSO REFERRED TO AS WAC CIRCUIT)
| Description: | Monitors the wide open throttle A/C cutoff (WAC) circuit output from the powertrain control module (PCM). The test fails when the PCM grounds the WAC circuit, excessive current draw is detected on the WAC circuit; or, with the WAC circuit not grounded by the PCM, voltage is not detected on the WAC circuit (the PCM expects to detect VPWR voltage coming through the WAC relay coil to the WAC circuit). | ||
| Possible Causes: |
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| Diagnostic Aids: | The A/CCR control circuit can be monitored using the WACF and WAC PID. When the WACF PID reads YES, a fault is present. An open circuit or short to ground can only be detected when the PCM is not grounding the circuit. A short to voltage can only be detected when the PCM is grounding the circuit. During the key on, engine off (KOEO) and key on, engine running (KOER) self-test, the WAC circuit is cycled on and off. Verify the A/C and the defrost were OFF during the KOEO and KOER self-tests. Check ACCS the PID to verify. If the vehicle is not equipped with A/C, DTC P0645 can be ignored. |
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| Application | Key On Engine Off | Key On Engine Running | Continuous Memory |
| All | GO to KM: Air Conditioning Clutch Relay (A/CCR) Circuit STEP KM1. | GO to KM: Air Conditioning Clutch Relay (A/CCR) Circuit STEP KM1. | GO to KM: Air Conditioning Clutch Relay (A/CCR) Circuit STEP KM9. |