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Test Procedure

  1. RH1 PRELIMINARY DIAGNOSIS 

    Are DTCs P209F, P20B9, P20BA, P20BB, P20BC, P20BD, P20BE, P20BF, P20C0, P20C1, P20C2, P20C3, P20C4, P214F, P21C2, P21C3, P21C4, P21C7, P21DD, P221C or P221D present? 

    Yes No
    For F-150, F-Series Super Duty and F-650/F-750, GO to  RH15.
    For all others, GO to  RH2.    		 RETURN to SYMPTOM CHARTS for further direction.
  2. RH2 CHECK THE REDUCTANT DOSAGE CONTROL MODULE FOR VOLTAGE 
    • Ignition OFF.
    • Reductant Dosage Control Module connector disconnected.
    • Connect a 5 amp fused jumper wire between the following:
      Point A Reductant Dosage Control Module Connector, Harness Side Point B
      RDCMRC - Pin 89 Ground
    • Ignition ON, engine OFF.
    • Measure the voltage between:
    (+) Reductant Dosage Control Module Connector, Harness Side (-)
    VPWR - Pin 1, 3, 5 Ground

    Is the voltage greater than 10.5 V? 

    Yes No
    For Transit Connect with DTCs P20BD, P20BE, P20BF or P20C0, GO to  RH10.
    For all others, GO to  RH6.    		 GO to  RH3.
  3. RH3 CHECK THE VOLTAGE TO THE REDUCTANT DOSAGE CONTROL MODULE RELAY 
    • Ignition OFF.
    • Reductant Dosage Control Module Relay connector disconnected.
    • Ignition ON, engine OFF.
    • Measure the voltage between:
    (+) Reductant Dosage Control Module Relay Connector, Harness Side (-)
    B+ - Pin 1, 3 Ground

    Is the voltage greater than 10.5 V? 

    Yes No
    GO to  RH4. REPAIR the open circuit.
    Clear the RDCM and PCM DTCs. REPEAT the self-test.
  4. RH4 CHECK THE REDUCTANT DOSAGE CONTROL MODULE RELAY 
    • Carry out the reductant dosage control module relay component test. Refer to the appropriate Component Testing Wiring Diagrams.

    Is a concern present? 

    Yes No
    INSTALL a new Reductant Dosage Control Module relay.
    Clear the RDCM and PCM DTCs. REPEAT the self-test.    		 GO to  RH5.
  5. RH5 CHECK THE REDUCTANT DOSAGE CONTROL MODULE CIRCUITS FOR AN OPEN 
    • Ignition OFF.
    • Measure the resistance between:
      (+) Reductant Dosage Control Module Relay Connector, Harness Side (-) Reductant Dosage Control Module Connector, Harness Side
      VPWR - Pin 5 VPWR - Pin 1, 3, 5
    • Measure the resistance between:
    (+) Reductant Dosage Control Module Connector, Harness Side (-)
    PWRGND Ground

    Is the resistance less than 5 ohms? 

    Yes No
    The system is operating correctly at this time.
    The concern may have been caused by a loose or corroded connector.    		 REPAIR the open circuit.
    Clear the RDCM and PCM DTCs. REPEAT the self-test.
  6. RH6 CHECK THE REDUCTANT TANK HEATER CIRCUITS FOR AN OPEN 
    • Ignition OFF.
    • Measure the resistance between:
      (+) Reductant Quality Module Connector, Harness Side (-) Reductant Dosage Control Module Connector, Harness Side
      RDHTRC1 RDHTRC1 - Pin 2
    • Measure the resistance between:
      (+) Reductant Quality Module Connector, Harness Side (-)
      GND Ground
    • Reductant Dosage Control Module connector disconnected.
    • Reductant Quality Module connector disconnected.

    Are the resistances less than 5 ohms? 

    Yes No
    GO to  RH7. REPAIR the open circuit.
    Clear the RDCM and PCM DTCs. REPEAT the self-test.
  7. RH7 CHECK THE RDHTRC1 CIRCUIT FOR A SHORT TO GROUND 
    • Measure the resistance between:
    (+) Reductant Quality Module Connector, Harness Side (-)
    RDHTRC1 Ground

    Is the resistance greater than 10K ohms? 

    Yes No
    GO to  RH8. REPAIR the short circuit.
    Clear the RDCM and PCM DTCs. REPEAT the self-test.
  8. RH8 CHECK THE REDUCTANT TANK HEATER CIRCUITS FOR A SHORT TO VOLTAGE 
    • Ignition ON, engine OFF.
    • Measure the voltage between:
    (+) Reductant Quality Module Connector, Harness Side (-)
    RDHTRC1 Ground
    GND Ground

    Is any voltage present? 

    Yes No
    REPAIR the short circuit.
    Clear the RDCM and PCM DTCs. REPEAT the self-test.    		 GO to  RH9.
  9. RH9 CHECK THE REDUCTANT TANK HEATER RESISTANCE 
    • Ignition OFF.
    • Measure the resistance between:
    (+) Reductant Quality Module Connector, Component Side (-) Reductant Quality Module Connector, Component Side
    RDHTRC1 GND

    Is the resistance between 1 - 2.5 ohms (Transit Connect) or 1.33 - 1.66 ohms (all others)? 

    Yes No
    GO to  RH14. INSTALL a new Reductant Quality module. REFER to the appropriate Engine Emission Control article.
    Clear the RDCM and PCM DTCs. REPEAT the self-test.
  10. RH10 CHECK THE REDUCTANT PRESSURE LINE HEATER ASSEMBLY CIRCUITS FOR AN OPEN 
    • Ignition OFF.
    • Reductant Dosage Control Module connector disconnected.
    • Reductant Pressure Line Heater Assembly connector disconnected.
    • Measure the resistance between:
    (+) Reductant Pressure Line Heater Assembly Connector, Harness Side (-) Reductant Dosage Control Module Connector, Harness Side
    RDHTRC2 RDHTRC2 - Pin 6
    • Measure the resistance between:
    (+) Reductant Pressure Line Heater Assembly Connector, Harness Side (-)
    GND Ground

    Are the resistances less than 5 ohms? 

    Yes No
    GO to  RH11. REPAIR the open circuit.
    For Transit Connect, clear the RDCM and PCM DTCs. REPEAT the self-test.
    For all others, clear the GPCM and PCM DTCs.
    REPEAT the self-test.
  11. RH11 CHECK THE RDHTRC2 CIRCUIT FOR A SHORT TO GROUND 
    • Measure the resistance between:
    (+) Reductant Pressure Line Heater Assembly Connector, Harness Side (-)
    RDHTRC2 Ground

    Is the resistance greater than 10K ohms? 

    Yes No
    GO to  RH12. REPAIR the short circuit.
    Clear the RDCM and PCM DTCs. REPEAT the self-test.
  12. RH12 CHECK THE REDUCTANT PRESSURE LINE HEATER ASSEMBLY CIRCUITS FOR A SHORT TO VOLTAGE 
    • Ignition ON, engine OFF.
    • Measure the voltage between:
    (+) Reductant Pressure Line Heater Assembly Connector, Harness Side (-)
    RDHTRC2 Ground
    GND Ground

    Is any voltage present? 

    Yes No
    REPAIR the short circuit.
    Clear the RDCM and PCM DTCs. REPEAT the self-test.    		 GO to  RH13.
  13. RH13 CHECK THE REDUCTANT PRESSURE LINE HEATER RESISTANCE 
    • Ignition OFF.
    • Measure the resistance between:
    (+) Reductant Pressure Line Heater Assembly Connector, Component Side (-) Reductant Pressure Line Heater Assembly Connector, Component Side
    RDHTRC2 GND

    Is the resistance between 3 - 5 ohms? 

    Yes No
    GO to  RH14. INSTALL a new Reductant Pressure Line Heater assembly. REFER to the appropriate Engine Emission Control article. Clear the GPCM and PCM DTCs. REPEAT the self-test.
  14. RH14 CHECK FOR CORRECT REDUCTANT DOSAGE CONTROL MODULE OPERATION 
    • Reductant Dosage Control Module connector disconnected.
    • Visually inspect for:
      • pushed out pins
      • corrosion
    • Connect the reductant dosage control module connector and make sure it seats correctly.
    • Carry out the DCU self-test.
    • Verify the concern is still present.

    Is the concern still present? 

    Yes No
    INSTALL a new Reductant Dosage Control module. REFER to the appropriate Electronic Engine Controls article. The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector.
  15. RH15 F-150, F-SERIES SUPER DUTY, AND F-650/F-750 

    Are DTCs P209F, P20B9, P20BA, P20BB, P20BC, P20BD, P20BE, P20BF, P20C0, P20C1, P20C2, P20C3, P20C4, P214F, P21C2, P21C3, P21C4, P21C7, P21DD, P221C or P221D present? 

    Yes No
    For DTCs P20BD, P20BF, P20BE, P20C0, P221C or P221D, GO to  RH23.
    For DTCs P209F, P20B9, P20BA, P20BB, P20BC, P214F or P21DD, GO to  RH19.
    For all others, GO to  RH16.    		 RETURN to SYMPTOM CHARTS for further direction.
  16. RH16 CHECK THE BJB CIRCUITS FOR AN OPEN 
    • Ignition OFF.
    • For F-150,
    • BJB-C connector disconnected.
    • GPCM-B connector disconnected.
    • Measure the resistance between:
      (+) BJB-C Connector, Harness Side (-)
      GND Ground
    • Measure the resistance between:
      (+) BJB-C Connector, Harness Side (-) GPCM-B Connector, Harness Side
      RDHTRCTRL RDHTRCTRL - Pin 28
      RDHTRPWR RDHTRPWR - Pin 14
    • For F-650/F-750,
    • BJB-H connector disconnected.
    • BJB-I connector disconnected.
    • GPCM-B connector disconnected.
    • Measure the resistance between:
      (+) BJB-H Connector, Harness Side (-) GPCM-B Connector, Harness Side
      RDHTRCTRL - Pin 30 RDHTRCTRL - Pin 28
    • Measure the resistance between:
      (+) BJB-I Connector, Harness Side (-)
      GND - Pin 35 Ground
    • Measure the resistance between:
      (+) BJB-I Connector, Harness Side (-) GPCM-B Connector, Harness Side
      RDHTRPWR - Pin 50 RDHTRPWR - Pin 14
    • For all others,
    • BJB-B connector disconnected.
    • GPCM-B connector disconnected.
    • Measure the resistance between:
      (+) BJB-B Connector, Harness Side (-)
      GND Ground
    • Measure the resistance between:
    (+) BJB-B Connector, Harness Side (-) GPCM-B Connector, Harness Side
    RDHTRCTRL RDHTRCTRL - Pin 28
    RDHTRPWR RDHTRPWR - Pin 14

    Are the resistances less than 5 ohms? 

    Yes No
    GO to  RH17. REPAIR the open circuit.
    Clear the GPCM and PCM DTCs. REPEAT the self-test.
  17. RH17 CHECK THE REDUCTANT HEATER RELAY CIRCUITS FOR A SHORT TO GND 
    • Measure the resistance between:
    (+) GPCM-B Connector, Harness Side (-)
    RDHTRPWR - Pin 14 Ground
    RDHTRCTRL - Pin 28 Ground

    Are the resistances greater than 10K ohms? 

    Yes No
    GO to  RH18. REPAIR the short circuit.
    Clear the GPCM and PCM DTCs. REPEAT the self-test.
  18. RH18 CHECK THE REDUCTANT HEATER CIRCUITS FOR A SHORT TO VOLTAGE 
    • Ignition ON, engine OFF.
    • Measure the voltage between:
    (+) GPCM-B Connector, Harness Side (-)
    RDHTRPWR - Pin 14 Ground
    RDHTRCTRL - Pin 28 Ground

    Is any voltage present? 

    Yes No
    REPAIR the short circuit.
    Clear the GPCM and PCM DTCs. REPEAT the self-test.    		 GO to  RH27.
  19. RH19 CHECK THE RDHTRC1 CIRCUITS FOR AN OPEN 
    • Ignition OFF.
    • Measure the resistance between:
      (+) Reductant Pump Assembly Connector, Harness Side (-) GPCM-B Connector, Harness Side
      RDHTRC1 - Pin 9 RDHTRC1 - Pin 1
    • Measure the resistance between:
    (+) Reductant Pump Assembly Connector, Harness Side (-)
    GND - Pin 11 Ground

    Are the resistances less than 5 ohms? 

    Yes No
    GO to  RH20. REPAIR the open circuit. Clear the GPCM and PCM DTCs. REPEAT the self-test.
  20. RH20 CHECK THE REDUCTANT TANK HEATER CIRCUITS FOR A SHORT TO GROUND 
    • Measure the resistance between:
    (+) Reductant Pump Assembly Connector, Harness Side (-)
    RDHTRC1 - Pin 9 Ground

    Is the resistance greater than 10K ohms? 

    Yes No
    GO to  RH21. REPAIR the short circuit. Clear the GPCM and PCM DTCs. REPEAT the self-test.
  21. RH21 CHECK THE RDHTRC1 CIRCUITS FOR A SHORT TO VOLTAGE 
    • Ignition ON, engine OFF.
    • Measure the voltage between:
    (+) Reductant Pump Assembly Connector, Harness Side (-)
    RDHTRC1 - Pin 9 Ground
    GND - Pin 11 Ground

    Is any voltage present? 

    Yes No
    REPAIR the short circuit. Clear the GPCM and PCM DTCs. REPEAT the self-test. GO to  RH22.
  22. RH22 CHECK THE RDHTRC1 RESISTANCE 
    • Ignition OFF.
    • Reductant Pump Assembly connector disconnected.
    • Measure the resistance between:
    (+) Reductant Pump Assembly Connector, Component Side (-) Reductant Pump Assembly Connector, Component Side
    RDHTRC1 - Pin 9 GND - Pin 11

    Is the resistance between 1.33 - 1.66 ohms? 

    Yes No
    GO to  RH27. INSTALL a new Reductant Pump assembly. REFER to the appropriate Engine Emission Control article. Clear the GPCM and PCM DTCs. REPEAT the self-test.
  23. RH23 CHECK THE RDHTRC2 AND REDUCTANT PUMP ASSEMBLY CIRCUITS FOR AN OPEN 
    • Ignition OFF.
    • GPCM-B connector disconnected.
    • Measure the resistance between:
      (+) Reductant Pressure Line Heater Assembly Connector, Harness Side (-) GPCM-B Connector, Harness Side
      RDHTRC2 RDHTRC2 - Pin 22
    • Measure the resistance between:
    (+) Reductant Pressure Line Heater Assembly Connector, Harness Side (-)
    GND Ground

    Are the resistances less than 5 ohms? 

    Yes No
    GO to  RH24. REPAIR the open circuit. Clear the GPCM and PCM DTCs. REPEAT the self-test.
  24. RH24 CHECK THE REDUCTANT PRESSURE LINE HEATER ASSEMBLY CIRCUIT FOR A SHORT TO GROUND 
    • Measure the resistance between:
    (+) Reductant Pressure Line Heater Assembly Connector, Harness Side (-)
    RDHTRC2 Ground

    Is the resistance greater than 10K ohms? 

    Yes No
    GO to  RH25. REPAIR the short circuit. Clear the GPCM and PCM DTCs. REPEAT the self-test.
  25. RH25 CHECK THE RDHTRC2 AND REDUCTANT PUMP ASSEMBLY CIRCUITS FOR A SHORT TO VOLTAGE 
    • Ignition ON, engine OFF.
    • Measure the voltage between:
    (+) Reductant Pressure Line Heater Assembly Connector, Harness Side (-)
    RDHTRC2 Ground
    GND Ground

    Is any voltage present? 

    Yes No
    REPAIR the short circuit. Clear the GPCM and PCM DTCs. REPEAT the self-test. GO to  RH26.
  26. RH26 CHECK THE RDHTRC2 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 GND

    Is the resistance between 3 - 5 ohms? 

    Yes No
    GO to  RH27. INSTALL a new Reductant Pressure Line Heater assembly. REFER to the appropriate Engine Emission Control article. Clear the GPCM and PCM DTCs. REPEAT the self-test.
  27. RH27 CHECK FOR CORRECT GPCM OPERATION 
    NOTE: Not all vehicles have all components listed.
    • Disconnect all the GPCM connectors.
    • Visually inspect for:
      • pushed out pins
      • corrosion
    • Connect all the GPCM connectors and make sure they seat correctly.
    • BJB-C connector connected.
    • BJB-H connector connected.
    • BJB-I connector connected.
    • Ignition ON, engine OFF.
    • Clear the PCM DTCs.
    • Carry out the PCM KOEO self-test.
    • Verify the concern is still present.

    Is the concern still present? 

    Yes No
    INSTALL a new GPCM. Refer to the appropriate 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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