LEMON Manuals: Even more car manuals for everyone
Home >> Mercury >> 2009 >> Sable Premier, FWD >> Repair and Diagnosis >> External Pages >> Different car >> Section 1255 (Engine Controls - Powertrain DTC Charts & Descriptions (Except Diesel & Hybrid)) >> DTC Diagnosis >> DTC P0645: - Air Conditioning Clutch Relay (A/CCR) Control Circuit

DTC P0645: - Air Conditioning Clutch Relay (A/CCR) Control Circuit

WARNING: This page does not describe the selected car, but rather 32 other vehicles, including the 2009 Mercury Mountaineer, 2009 Mercury Milan, 2009 Mercury Mariner, 2009 Mercury Grand Marquis, and 2009 Lincoln Town Car. However, it is still accessible from the selected car via links, so may be relevant.
DTC P0645: - AIR CONDITIONING CLUTCH RELAY (A/CCR) CONTROL CIRCUIT

Description:  Monitors the A/CCR circuit output from the powertrain control module (PCM). The test fails when the PCM grounds the A/CCR circuit, excessive current draw is detected on the A/CCR circuit; or, with the A/CCR circuit not grounded by the PCM, voltage is not detected on the A/CCR circuit (the PCM expects to detect VPWR voltage coming through the A/CCR relay coil to the A/CCR circuit).
Possible Causes: 
  • Open or short A/CCR circuit
  • Damaged A/CCR relay
  • Open VPWR circuit to the A/CCR relay
Diagnostic Aids:  The A/CCR control circuit can be monitored using the WACF and WAC PID.
When the WACF PID reads YES, a concern 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 PID to verify. If the vehicle is not equipped with A/C, ignore DTC P0645.
Application  Key On Engine Off  Key On Engine Running  Continuous Memory 
All GO to Pinpoint Test KM .