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Home >> Ford >> 2000 >> Contour SE, 2.5 L, Standard >> Repair and Diagnosis >> External Pages >> Different car >> Section 747 (Engine Controls - Pinpoint Tests - 6.0L Diesel (99P E-Series & 99P F450/550)) >> Pinpoint Test AV: Air Conditioning Relay Control Circuit >> Test Procedure

Test Procedure

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  1. AV1 PRELIMINARY DIAGNOSIS FOR DTC P0645 
    • Perform visual inspection.
    • Connect the scan tool.
    • Retrieve and record all DTCs.
    • Clear all DTCs.
    • Perform on-demand self test.

    IS DTC P0645 SET? 

    Yes No
    Go to  AV2. Unable to duplicate condition. CHECK for loose connections, damaged or corroded pins. WIGGLE the harness to attempt to recreate the fault. CLEAR all DTCs and return the vehicle to service.
  2. AV2 DIAGNOSTIC TROUBLE CODE (DTC) P0645 
    • Possible causes:
      • A/C control circuit shorted to voltage
      • A/C control circuit open
      • A/C control circuit shorted to ground
      • A/C relay circuit
      • A/C relay
      • PCM
    • Key on, engine off.
    • Access ACCS PID
    • Select A/C control switch "OFF" and then "ON"

    IS ACCS PID INDICATING "OFF" WHEN SELECTED AND "ON" WHEN SELECTED? 

    Yes No
    Go to  AV3. refer to the appropriate CLIMATE CONTROL SYSTEM article to diagnose the A/C request does not operate.
  3. AV3 CHECK A/C RELAY CIRCUIT 
    NOTE: Refer to the wiring diagram, Figure and Figure at the beginning of this pinpoint test.
    • Key off.
    • Remove the A/C relay.
    • Install a test light between auxiliary relay box A/C relay socket VPWR circuit pin 2 and ground.
    • Key on.

    DOES THE TEST LIGHT ILLUMINATE? 

    Yes No
    Go to  AV4. REPAIR open in circuit. RESTORE the vehicle and RETEST the system. Go to  AV4.
  4. AV4 CHECK A/C CONTROL CIRCUIT 
    • Install a test light between auxiliary relay box A/C relay socket pin 2 and pin 1.
    • Start engine.
    • Select A/C on and then off.

    DOES THE TEST LIGHT ILLUMINATE WITH A/C ON AND THEN OFF WHEN A/C IS TURNED OFF? 

    Yes No
    INSTALL a new A/C relay. RESTORE the vehicle. CLEAR the DTCs and RETEST the system. Go to  AV5.
  5. AV5 CHECK A/C CONTROL CIRCUIT FOR A SHORT TO VOLTAGE 
    • Engine off, key off.
    • Disconnect the PCM body harness connector.
    • Key on.
    • Measure the voltage between PCM body harness connector pin 2 and ground.

    IS THE VOLTAGE LESS THAN 0.2 VOLTS? 

    Yes No
    Go to  AV6. REPAIR short to voltage in the relay control circuit. RESTORE the vehicle. CLEAR the DTCs and RETEST the system.
  6. AV6 CHECK A/C RELAY CONTROL CIRCUIT FOR A SHORT TO GROUND 
    • Measure the resistance between PCM body harness connector pin 2, and ground.

    IS THE RESISTANCE GREATER THAN 10,000 OHMS? 

    Yes No
    Go to  AV7. REPAIR short to ground in relay control circuit. RESTORE the vehicle. CLEAR DTCs and RETEST the system.
  7. AV7 CHECK A/C RELAY CONTROL CIRCUIT FOR AN OPEN 
    • Measure the resistance between PCM body harness connector pin 2, and auxiliary relay box A/C relay connector socket pin 1.

    IS THE RESISTANCE LESS THAN 5 OHMS? 

    Yes No
    INSTALL a new PCM. RESTORE the vehicle and RETEST the system. REPAIR open on circuit. RESTORE the vehicle and RETEST the system.
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