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Home >> Ford >> 2021 >> F-150 Raptor >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls - Pinpoint Tests (Diesel) >> Pinpoint Tests AJ: Powertrain Control Module (PCM) Power Relay >> Test Procedure
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Test Procedure

  1. AJ1 CHECK FOR DTCS 

    Are DTCs P0685, P068A, P068B, P2507 or P2508 present? 

    Yes No
    GO to  AJ2. For symptoms without DTCs, GO to  AJ3.
    For all others, RETURN to SYMPTOM CHARTS for further direction.
  2. AJ2 CHECK THE BATTERY AND CHARGING SYSTEM 
    • Check the battery and charging system voltages. Refer to the appropriate Charging System, Inspection and Verification article.

    Are the battery and charging system voltages within specifications? 

    Yes No
    For F-150, F-Series Super Duty and F-650/F-750, GO to  AJ5.
    For all others, GO to  AJ3.    		 REPAIR as necessary. REFER to the appropriate Charging System, Symptom Chart to diagnose the system voltage low or battery is discharged symptom or the system voltage high symptom.
    Clear the PCM DTCs. REPEAT the self-test.
  3. AJ3 CHECK THE PCM POWER RELAY 
    • Carry out the PCM power relay component test. Refer to the appropriate Component Testing Wiring Diagrams.

    Did the PCM power relay pass the component test? 

    Yes No
    GO to  AJ4. INSTALL a new PCM Power Relay. Clear the PCM DTCs. REPEAT the self-test.
  4. AJ4 CHECK THE B+ CIRCUITS FOR VOLTAGE 
    • Ignition OFF.
    • PCM Power Relay connector disconnected.
    • Measure the voltage between:
    (+) PCM Power Relay Connector, Harness Side (-)
    B+ - Pin 1, 3 Ground

    Is the voltage greater than 10.5 V? 

    Yes No
    GO to  AJ5. REPAIR the open circuit. Clear the PCM DTCs.
    REPEAT the self-test.
  5. AJ5 CHECK THE PCMRC CIRCUIT FOR AN OPEN 
    • PCM-B connector disconnected.
    • For F-150,
    • BJB-C connector disconnected.
    • Measure the resistance between:
      (+) BJB-C Connector, Harness Side (-) PCM-B Connector, Harness Side
      PCMRC - Pin 20 PCMRC
    • For F-Series Super Duty,
    • BJB-A connector disconnected.
    • Measure the resistance between:
      (+) BJB-A Connector, Harness Side (-) PCM-B Connector, Harness Side
      PCMRC - Pin 39 PCMRC
    • For F-650/F-750,
    • BJB-H connector disconnected.
    • Measure the resistance between:
      (+) BJB-H Connector, Harness Side (-) PCM-B Connector, Harness Side
      PCMRC - Pin 18 PCMRC
    • For all others,
    • Measure the resistance between:
    (+) PCM-B Connector, Harness Side (-) PCM Power Relay Connector, Harness Side
    PCMRC PCMRC - Pin 2

    Is the resistance less than 5 ohms? 

    Yes No
    GO to  AJ6. REPAIR the open circuit. Clear the PCM DTCs.
    REPEAT the self-test.
  6. AJ6 CHECK THE PCMRC CIRCUIT FOR A SHORT TO GROUND 
    • Measure the resistance between:
    (+) PCM-B Connector, Harness Side (-)
    PCMRC Ground

    Is the resistance greater than 10K ohms? 

    Yes No
    GO to  AJ7. REPAIR the short circuit. Clear the PCM DTCs.
    REPEAT the self-test.
  7. AJ7 CHECK THE PCMRC CIRCUIT FOR A SHORT TO VOLTAGE 
    • Ignition ON, engine OFF.
    • Measure the voltage between:
    (+) PCM-B Connector, Harness Side (-)
    PCMRC Ground

    Is any voltage present? 

    Yes No
    REPAIR the short circuit. Clear the PCM DTCs.
    REPEAT the self-test.    		 GO to  AJ8.
  8. AJ8 CHECK THE ISP-R CIRCUIT FOR VOLTAGE 
    • For F-150 and F-Series Super Duty,
    • Ignition OFF.
    • BJB-B connector connected.
    • Ignition ON, engine OFF.
    • Measure the voltage between:
      (+) PCM-B Connector, Harness Side (-)
      ISP-R Ground
    • For F-650/F-750,
    • BJB-H connector connected.
    • Ignition ON, engine OFF.
    • Measure the voltage between:
      (+) PCM-B Connector, Harness Side (-)
      ISP-R Ground
    • For all others,
    • Ignition OFF.
    • PCM Power Relay connector connected.
    • Ignition ON, engine OFF.
    • Measure the voltage between:
    (+) PCM-B Connector, Harness Side (-)
    ISP-R Ground

    Is the voltage greater than 10.5 V? 

    Yes No
    GO to  AJ9. REPAIR the open circuit. Clear the PCM DTCs.
    REPEAT the self-test.
  9. AJ9 CHECK THE ISP-R CIRCUIT FOR A SHORT TO VOLTAGE 
    • Ignition OFF.
    • Measure the voltage between:
    (+) PCM-B Connector, Harness Side (-)
    ISP-R Ground

    Is any voltage present? 

    Yes No
    REPAIR the short circuit. Clear the PCM DTCs.
    REPEAT the self-test.    		 GO to  AJ10.
  10. AJ10 CHECK THE VPWR CIRCUIT FOR AN OPEN 
    • For F-Series Super Duty,
    • BJB-A connector disconnected.
    • Measure the resistance between:
      (+) PCM-B Connector, Harness Side (-) BJB-A Connector, Harness Side
      VPWR VPWR - Pin 51
    • For F-150,
    • BJB-B connector disconnected.
    • Measure the resistance between:
      (+) PCM-B Connector, Harness Side (-) BJB-B Connector, Harness Side
      VPWR VPWR - Pin 46
    • For F-650/F-750,
    • BJB-G connector disconnected.
    • Measure the resistance between:
      (+) PCM-B Connector, Harness Side (-) BJB-G Connector, Harness Side
      VPWR VPWR - Pin 34
    • For all others,
    • PCM Power Relay connector disconnected.
    • Measure the resistance between:
    (+) PCM-B Connector, Harness Side (-) PCM Power Relay Connector, Harness Side
    VPWR VPWR - Pin 5

    Are the resistances less than 5 ohms? 

    Yes No
    GO to  AJ11. REPAIR the open circuit. Clear the PCM DTCs.
    REPEAT the self-test.
  11. AJ11 CHECK THE PWRGND CIRCUITS FOR AN OPEN 
    • Measure the resistance between:
    (+) PCM-B Connector, Harness Side (-)
    PWRGND Ground

    Are the resistances less than 5 ohms? 

    Yes No
    For F-150, F-Series Super Duty, and F-650/F-750. GO to  AJ12.
    For all others, GO to  AJ13.    		 REPAIR the open circuit. Clear the PCM DTCs.
    REPEAT the self-test.
  12. AJ12 CHECK THE BJB 
    • For F-150,
    • Connect a 5 amp fused jumper wire between the following:
      Point A BJB-C Connector, Component Side Point B
      PCMRC - Pin 20 Ground
    • Measure the voltage between:
      (+) BJB-B Connector, Harness Side (-)
      VPWR - Pin 46 Ground
    • For F-650/F-750,
    • Connect a 5 amp fused jumper wire between the following:
      Point A BJB-H Connector, Component Side Point B
      PCMRC - Pin 18 Ground
    • Measure the voltage between:
      (+) BJB-G Connector, Harness Side (-)
      VPWR - Pin 34 Ground
    • For F-Series Super Duty,
    • Connect a 5 amp fused jumper wire between the following:
      Point A BJB-A Connector, Component Side Point B
      PCMRC - Pin 39 Ground
    • Measure the voltage between:
    (+) BJB-A Connector, Harness Side (-)
    VPWR - Pin 51 Ground

    Is the voltage greater than 10.5 V? 

    Yes No
    INSTALL a new BJB. CLEAR the DTCs.
    REPEAT the self-test.    		 REPAIR the open circuit. Clear the PCM DTCs.
    REPEAT the self-test.
  13. AJ13 CHECK FOR CORRECT PCM OPERATION 
    • 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.
    • 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) .    		 The system is operating correctly at this time.
    The concern may have been caused by a loose or corroded connector.
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