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Home >> Ford >> 2010 >> Expedition EL 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  B12.    		 GO to  B2.
  2. B2 CHECK THE B+ AND IGN START/RUN VOLTAGE TO PCM POWER RELAY 
    • Ignition OFF.
    • PCM Power Relay connector disconnected.
    • Ignition 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,
    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 
    • Ignition OFF.
    • 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 
    • Ignition 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 
    • Ignition OFF.
    • PCM Power Relay connector connected.
    • Ignition 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 
    • Ignition OFF.
    • 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 
    • Ignition OFF.
    • 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 
    • Ignition OFF.
    • 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. For Flex 3.5L GTDI,
    MKS 3.5L,
    MKT 3.5L, and
    Taurus 3.5L GTDI, GO to  B11.
    For all others, 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 - Pin 2

    Is the resistance less than 5 ohms? 

    Yes No
    GO to  B13. REPAIR the open circuit. CLEAR the DTCs. REPEAT the self-test.
  11. B11 CHECK THE INJPWR_M PID 
    • Ignition OFF.
    • PCM Power Relay connector connected.
    • PCM connector connected.
    • Ignition ON, engine OFF.
    • Access the PCM and monitor the INJPWR_M PID.
    • Record the INJPWR_M PID value.
    • Ignition OFF.
    • Record the INJPWR_M PID value.

    Is the INJPWR_M PID voltage reading above 10.5 V with key ON and 0 V with the key OFF? 

    Yes No
    GO to  B13. REPAIR the circuit.
    CLEAR the DTCs. REPEAT the self-test.
  12. B12 DTC P0689: CHECK THE ISP-R VOLTAGE AT THE PCM HARNESS CONNECTOR 
    • Ignition OFF.
    • PCM connector disconnected.
    • Ignition 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  B13. REPAIR the open circuit. CLEAR the DTCs. REPEAT the self-test.
  13. B13 CHECK FOR CORRECT PCM OPERATION 
    • Ignition OFF.
    • 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 to FLASH 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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