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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. RH1 PRELIMINARY DIAGNOSIS 

    Are DTCs P209F, P20B9, P20BA, P20BB, P20BC, P20BD, P20BE, P20BF, P20C0, P20C1, P20C2, P20C3 or P20C4 present? 

    Yes No
    For DTCs P209F, P20B9, P20BA, P20BB or P20BC, GO to  RH2.
    For DTCs P20BD, P20BE, P20BF or P20C0, GO to  RH6.
    For DTCs P20C1, P20C2, P20C3 or P20C4, GO to  RH11.    		 Unable to duplicate the condition. CHECK for a loose connection, and damaged or corroded terminals. WIGGLE the harness attempting to recreate the concern. REPAIR as necessary. REFER to NO DIAGNOSTIC TROUBLE CODES (DTCS) PRESENT SYMPTOM CHART INDEX , if a driveability concern exists.
  2. RH2 DTCS P209F, P20B9, P20BA, P20BB OR P20BC: CHECK THE REDUCTANT TANK HEATER RESISTANCE 
    • Ignition OFF.
    • Reductant Heater and Sender Assembly connector disconnected.
    • Measure the resistance between:
      (+) Reductant Heater and Sender Assembly Connector, Component Side (-) Reductant Heater and Sender Assembly Connector, Component Side
      RDHTRC1 - Pin 1 GND - Pin 2

    Is the resistance between 1 - 2.5 ohms? 

    Yes No
    GO to  RH3. INSTALL a new Reductant Heater and Sender assembly. REFER to the appropriate Engine Emission Control article.
    Clear the PCM DTCs. REPEAT the self-test.
  3. RH3 CHECK THE REDUCTANT TANK HEATER CIRCUITS FOR AN OPEN 
    • GPCM-C connector disconnected.
    • Measure the resistance between:
      (+) Reductant Heater and Sender Assembly Connector, Harness Side (-) GPCM-C Connector, Harness Side
      RDHTRC1 - Pin 1 RDHTRC1 - Pin 15
    • Measure the resistance between:
      (+) Reductant Heater and Sender Assembly Connector, Harness Side (-)
      GND - Pin 2 Ground

    Are the resistances less than 5 ohms? 

    Yes No
    GO to  RH4. REPAIR the open circuit. Clear the PCM DTCs.
    REPEAT the self-test.
  4. RH4 CHECK THE RDHTRC1 CIRCUIT FOR A SHORT TO GROUND 
    • Measure the resistance between:
      (+) GPCM-C Connector, Harness Side (-)
      RDHTRC1 - Pin 15 Ground

    Is the resistance greater than 10K ohms? 

    Yes No
    GO to  RH5. REPAIR the short circuit. Clear the PCM DTCs.
    REPEAT the self-test.
  5. RH5 CHECK THE REDUCTANT TANK HEATER CIRCUITS FOR A SHORT TO VOLTAGE 
    • Ignition ON, engine OFF.
    • Measure the voltage between:
      (+) GPCM-C Connector, Harness Side (-)
      RDHTRC1 - Pin 15 Ground
    • Measure the voltage between:
      (+) Reductant Heater and Sender Assembly Connector, Harness Side (-)
      GND - Pin 2 Ground

    Is any voltage present? 

    Yes No
    REPAIR the short circuit. Clear the PCM DTCs.
    REPEAT the self-test.    		 GO to  RH15.
  6. RH6 DTCS P20BD, P20BE, P20BF OR P20C0: CHECK THE REDUCTANT PRESSURE LINE HEATER RESISTANCE 
    • Ignition OFF.
    • Reductant Pressure Line Heater Assembly connector disconnected.
    • Measure the resistance between:
      (+) Reductant Pressure Line Heater Assembly Connector, Component Side (-) Reductant Pressure Line Heater Assembly Connector, Component Side
      RDHTRC2 - Pin 1 GND - Pin 2

    Is the resistance between 3 - 5 ohms? 

    Yes No
    GO to  RH7. INSTALL a new Reductant Pressure Line Heater assembly. REFER to the appropriate Engine Emission Control article.
    Clear the PCM DTCs. REPEAT the self-test.
  7. RH7 CHECK THE REDUCTANT PUMP ASSEMBLY HEATER RESISTANCE 
    • Reductant Pump Assembly connector disconnected.
    • Measure the resistance between:
      (+) Reductant Pump Assembly Connector, Component Side (-) Reductant Pump Assembly Connector, Component Side
      RDHTRC2 - Pin 2 GND - Pin 1

    Is the resistance between 2.5 - 6 ohms? 

    Yes No
    GO to  RH8. INSTALL a new Reductant Pump assembly. REFER to the appropriate Engine Emission Control article.
    Clear the PCM DTCs. REPEAT the self-test.
  8. RH8 CHECK THE REDUCTANT PRESSURE LINE HEATER ASSEMBLY AND REDUCTANT PUMP ASSEMBLY CIRCUITS FOR AN OPEN 
    • GPCM-C connector disconnected.
    • Measure the resistance between:
      (+) Reductant Pressure Line Heater Assembly Connector, Harness Side (-) GPCM-C Connector, Harness Side
      RDHTRC2 - Pin 1 RDHTRC2 - Pin 13
    • Measure the resistance between:
      (+) Reductant Pressure Line Heater Assembly Connector, Harness Side (-)
      GND - Pin 2 Ground
    • Measure the resistance between:
      (+) Reductant Pump Assembly Connector, Harness Side (-) GPCM-C Connector, Harness Side
      RDHTRC2 - Pin 2 RDHTRC2 - Pin 13
    • Measure the resistance between:
      (+) Reductant Pump Assembly Connector, Harness Side (-)
      GND - Pin 1 Ground

    Are the resistances less than 5 ohms? 

    Yes No
    GO to  RH9. REPAIR the open circuit. Clear the PCM DTCs.
    REPEAT the self-test.
  9. RH9 CHECK THE RDHTRC2 CIRCUIT FOR A SHORT TO GROUND 
    • Measure the resistance between:
      (+) GPCM-C Connector, Harness Side (-)
      RDHTRC2 - Pin 13 Ground

    Is the resistance greater than 10K ohms? 

    Yes No
    GO to  RH10. REPAIR the short circuit. Clear the PCM DTCs.
    REPEAT the self-test.
  10. RH10 CHECK THE REDUCTANT PRESSURE LINE HEATER ASSEMBLY AND REDUCTANT PUMP ASSEMBLY CIRCUITS FOR A SHORT TO VOLTAGE 
    • Ignition ON, engine OFF.
    • Measure the voltage between:
      (+) GPCM-C Connector, Harness Side (-)
      RDHTRC2 - Pin 13 Ground
    • Measure the voltage between:
      (+) Reductant Pressure Line Heater Assembly Connector, Harness Side (-)
      GND - Pin 2 Ground
    • Measure the voltage between:
      (+) Reductant Pump Assembly Connector, Harness Side (-)
      GND - Pin 1 Ground

    Is any voltage present? 

    Yes No
    REPAIR the short circuit. Clear the PCM DTCs.
    REPEAT the self-test.    		 GO to  RH15.
  11. RH11 DTCS P20C1, P20C2, P20C3 OR P20C4: CHECK THE REDUCTANT HEATER RELAY 
    • Carry out the reductant heater relay component test. Refer to the appropriate ELECTRONIC ONTROLS - COMPONENT TESTING article .

    Is a concern present? 

    Yes No
    INSTALL a new Reductant Heater relay. Clear the PCM DTCs. REPEAT the self-test. GO to  RH12.
  12. RH12 CHECK THE RDHTRPWR CIRCUIT FOR AN OPEN 
    • Reductant Heater Relay connector disconnected.
    • GPCM-C connector disconnected.
    • Measure the resistance between:
      (+) Reductant Heater Relay Connector, Harness Side (-) GPCM-C Connector, Harness Side
      RDHTRPWR - Pin 5 RDHTRPWR - Pin 16

    Is the resistance less than 5 ohms? 

    Yes No
    GO to  RH13. REPAIR the open circuit. Clear the PCM DTCs.
    REPEAT the self-test.
  13. RH13 CHECK THE RDHTRPWR CIRCUIT FOR A SHORT TO GROUND 
    • Measure the resistance between:
      (+) GPCM-C Connector, Harness Side (-)
      RDHTRPWR - Pin 16 Ground

    Is the resistance greater than 10K ohms? 

    Yes No
    GO to  RH14. REPAIR the short circuit. Clear the PCM DTCs.
    REPEAT the self-test.
  14. RH14 CHECK THE RDHTRPWR CIRCUIT FOR A SHORT TO VOLTAGE 
    • Ignition ON, engine OFF.
    • Measure the voltage between:
      (+) GPCM-C Connector, Harness Side (-)
      RDHTRPWR - Pin 16 Ground

    Is any voltage present? 

    Yes No
    REPAIR the short circuit. Clear the PCM DTCs.
    REPEAT the self-test.    		 GO to  RH15.
  15. RH15 CHECK FOR CORRECT GPCM OPERATION 
    • Disconnect all the GPCM connectors.
    • Visually inspect for:
      • pushed out pins
      • corrosion
    • Connect all the GPCM connectors and make sure they seat correctly.
    • Verify the concern is still present.

    Is the concern still present? 

    Yes No
    INSTALL a new GPCM. Refer to the Glow Plug System article.
    Clear the PCM DTCs. REPEAT the self-test.    		 The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector.
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