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Home >> Ford >> 2008 >> Explorer 4.6 8, 4WD >> Repair and Diagnosis (Single Page) >> Engine Performance >> Testing & Diagnosis >> Engine Controls - Pinpoint Test A: No Start Through Pinpoint Test DK: Accelerator Pedal Position (App) Sensor - (Except Diesel & Hybrid) >> PINPOINT TEST B: Powertrain Control Module (PCM) Power Relay >> Test Procedure
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Test Procedure

  1. B1 CHECK FOR DIAGNOSTIC TROUBLE CODES (DTCS) 
    • Is DTC P0685, P0689, or P0690 present? 
    Yes No
    For DTCs P0685 or P0690, GO to  B8.
    For DTC P0689, GO to  B11.    		 GO to  B2.
  2. B2 CHECK THE B+ AND IGN START/RUN VOLTAGE TO PCM POWER RELAY 
    • Key in OFF position.
    • PCM Power Relay connector disconnected.
    • Key ON, engine OFF.
    • Measure the voltage between:
      ( + ) PCM Power Relay Connector, Harness Side ( - )
      B+ Ground
      IGN START/RUN Ground
    • Are the voltages greater than 10 V? 
    Yes No
    For Crown Victoria,
    Grand Marquis,
    E-Series,
    Escape/Mariner,
    Ranger, and
    Town Car, GO to  B6.
    For all others, GO to  B3.    		 REPAIR the open circuit. CLEAR the DTCs. REPEAT the self-test.
  3. B3 CHECK THE PCMRC CIRCUIT FOR AN OPEN IN THE HARNESS 
    • Key in OFF position.
    • PCM connector disconnected.
    • Measure the resistance between:
      ( + ) PCM Power Relay Connector, Harness Side ( - ) PCM Connector, Harness Side
      PCMRC PCMRC
    • Is the resistance less than 5 ohms? 
    Yes No
    GO to  B4. REPAIR the open circuit. CLEAR the DTCs. REPEAT the self-test.
  4. B4 CHECK THE PCMRC CIRCUIT FOR A SHORT TO VOLTAGE IN THE HARNESS 
    • Key ON, engine OFF.
    • Measure the voltage between:
      ( + ) PCM Connector, Harness Side ( - )
      PCMRC Ground
    • Is any voltage present? 
    Yes No
    REPAIR the short circuit. CLEAR the DTCs. REPEAT the self-test. GO to  B5.
  5. B5 CHECK THE ISP-R VOLTAGE AT THE PCM HARNESS CONNECTOR 
    • Key in OFF position.
    • PCM Power Relay connector connected.
    • Key ON, engine OFF.
    • Measure the voltage between:
      ( + ) PCM Connector, Harness Side ( - )
      ISP-R Ground
    • Is the voltage greater than 10 V? 
    Yes No
    GO to  B7. REPAIR the open circuit. CLEAR the DTCs. REPEAT the self-test.
  6. B6 CHECK THE PCM POWER RELAY GROUND CIRCUIT FOR AN OPEN 
    • Measure the voltage between:
      ( + ) PCM Power Relay Connector, Harness Side ( - ) PCM Power Relay Connector, Harness Side
      B+ GND
    • Is the voltage greater than 10 V? 
    Yes No
    GO to  B7. REPAIR the open circuit. CLEAR the DTCs. REPEAT the self-test.
  7. B7 CHECK FOR AN OPEN VPWR CIRCUIT BETWEEN THE PCM AND POWER RELAY 
    • Key in OFF position.
    • PCM connector disconnected.
    • Measure the resistance between:
      ( + ) PCM Power Relay Connector, Harness Side ( - ) PCM Connector, Harness Side
      VPWR VPWR
    • Is the resistance less than 5 ohms? 
    Yes No
    INSTALL a new PCM Power relay.
    CLEAR the DTCs. REPEAT the self-test.    		 REPAIR the open circuit. CLEAR the DTCs. REPEAT the self-test.
  8. B8 DTCS P0685 OR P0690: CHECK THE PCMRC CIRCUIT FOR A SHORT TO GROUND IN THE HARNESS 
    • Key in OFF position.
    • PCM Power Relay connector disconnected.
    • PCM connector disconnected.
    • Measure the resistance between:
      ( + ) PCM Connector, Harness Side ( - )
      PCMRC Ground
    • Is the resistance greater than 10K ohms? 
    Yes No
    GO to  B9. REPAIR the short circuit. CLEAR the DTCs. REPEAT the self-test.
  9. B9 CHECK THE ISP-R CIRCUIT FOR A SHORT TO VOLTAGE IN THE HARNESS 
    • Key in OFF position.
    • Measure the voltage between:
      ( + ) PCM Connector, Harness Side ( - )
      ISP-R Ground
    • Is any voltage present? 
    Yes No
    REPAIR the short circuit. CLEAR the DTCs. REPEAT the self-test. GO to  B10.
  10. B10 CHECK THE INJPWRM CIRCUIT FOR AN OPEN IN THE HARNESS 
    • INJ connector disconnected.
    • Measure the resistance between:
      ( + ) PCM Connector, Harness Side ( - ) INJ Connector, Harness Side
      INJPWRM VPWR
    • Is the resistance less than 5 ohms? 
    Yes No
    GO to  B12. REPAIR the open circuit. CLEAR the DTCs. REPEAT the self-test.
  11. B11 DTC P0689: CHECK THE ISP-R VOLTAGE AT THE PCM HARNESS CONNECTOR 
    • Key in OFF position.
    • PCM connector disconnected.
    • Key ON, engine OFF.
    • Measure the voltage between:
      ( + ) PCM Connector, Harness Side ( - )
      ISP-R Ground
    • Is the voltage greater than 10 V? 
    Yes No
    GO to  B12. REPAIR the open circuit. CLEAR the DTCs. REPEAT the self-test.
  12. B12 CHECK FOR CORRECT PCM OPERATION 
    • Key in OFF position.
    • Disconnect all the PCM connectors.
    • Visually inspect for:
      • pushed out pins
      • corrosion
    • Connect all the PCM connectors and make sure they seat correctly.
    • Carry out the PCM self-test and verify the concern is still present.
    • Is the concern still present? 
    Yes No
    INSTALL a new PCM. REFER toFLASH ELECTRICALLY ERASABLE PROGRAMMABLE READ ONLY MEMORY (EEPROM) , Programming the VID Block for a Replacement PCM. The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector.
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