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Home >> Ford >> 2012 >> Taurus SE >> Repair and Diagnosis >> External Pages >> Different car >> Section 1848 (Engine Controls - Pinpoint Tests (Diesel)) >> Pinpoint Tests AJ: Powertrain Control Module (PCM) Power Relay >> Test Procedure
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Test Procedure

WARNING: This page is about a different car, the 2012 Ford Pickup, 2012 Ford F550 Super Duty, 2012 Ford F450 Super Duty, and 2012 Ford Cab & Chassis. However, it is still accessible from the selected car via links, so may be relevant.
  1. AJ1 CHECK FOR DIAGNOSTIC TROUBLE CODES (DTC) 

    Is DTC P0685, P068A, P2506, P2507 or P2508 present? 

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

    Are the battery and charging system voltages within specifications? 

    Yes No
    GO to  AJ3. REPAIR as necessary. REFER to the appropriate Charging System article, 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 ELECTRONIC CONTROLS - COMPONENT TESTING article .

    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 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.
    • Measure the resistance between:
      (+) PCM-B Connector, Harness Side (-) PCM Power Relay Connector, Harness Side
      PCMRC - Pin 38 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 
    • Ignition OFF.
    • Measure the resistance between:
      (+) PCM-B Connector, Harness Side (-)
      PCMRC - Pin 38 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 - Pin 38 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 
    • PCM Power Relay connector connected.
    • Ignition ON, engine OFF.
    • Measure the voltage between:
      (+) PCM-B Connector, Harness Side (-)
      ISP-R - Pin 42 Ground

    Is the voltage greater than 10 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 - Pin 42 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 
    • PCM Power Relay connector disconnected.
    • Measure the resistance between:
      (+) PCM-B Connector, Harness Side (-) PCM Power Relay Connector, Harness Side
      VPWR - Pin 67, 68, 69 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 - Pin 70, 71, 72, 73, 74 Ground

    Are the resistances less than 5 ohms? 

    Yes No
    GO to  AJ12. REPAIR the open circuit. Clear the PCM DTCs.
    REPEAT the self-test.
  12. AJ12 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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