LEMON Manuals: Even more car manuals for everyone
Home >> Ford >> 2002 >> Cutaway 7.3 F >> Repair and Diagnosis >> External Pages >> Different car >> Section 1881 (Engine Controls - Diagnostic Subroutines -- Diesel 6.0L (99P E-Series & 99P F450/550)) >> Diagnostic Trouble Code (DTC) Charts and Descriptions >> P0645 - A/C Clutch Relay Control Circuit

P0645 - A/C Clutch Relay Control Circuit

WARNING: This page does not describe the selected car, but rather 7 other vehicles, including the 2007 Ford RV Cutaway, 2007 Ford Pickup, 2007 Ford F550 Super Duty, 2007 Ford F450 Super Duty, and 2007 Ford Econoline. However, it is still accessible from the selected car via links, so may be relevant.
P0645 - A/C CLUTCH RELAY 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 shorted 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 parameter identification (PID).
When the WACF PID reads YES, a concern is present.
An open circuit or a 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 the ACCS PID to verify. If the vehicle is not equipped with A/C, DTC P0645 can be ignored.
Application    Key On Engine Off  Key On Engine Running  Continuous Memory 
All   refer to PINPOINT TEST AV .
scientia non olet · About LEMON Manuals