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HOMESERVICE MANUALSFORD2021TRANSIT-350 HD BASE, VAN CARGO EXTENDED, 3.5L ENG VIN 8, AWDREPAIR AND DIAGNOSISEXTERNAL PAGESDIFFERENT CARSECTION 13 (ENGINE CONTROLS - PINPOINT TESTS (DIESEL))PINPOINT TESTS RF: REDUCTANT PRESSURE SENSORTEST PROCEDURE
2021 Ford Transit-350 HD Base, Van Cargo Extended, 3.5L Eng VIN 8, AWD

Test Procedure

2021 Ford Transit-350 HD Base, Van Cargo Extended, 3.5L Eng VIN 8, AWDSECTION Test Procedure
WARNING: This page does not describe the selected car, but rather 9 other vehicles, including the 2018 Ford Transit-350 HD, 2018 Ford Transit-350, 2018 Ford Transit-250, 2018 Ford Transit-150, and 2018 Ford F-550 Super Duty. However, it is still accessible from the selected car via links, so may be relevant.
  1. RF1 PRELIMINARY DIAGNOSIS 

    Are DTCs P204B, P204C, P204D, or P204E present? 

    Yes No
    GO to  RF2. 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.
    RETURN to SYMPTOM CHARTS for further direction.
  2. RF2 CHECK THE REDUCTANT PRESSURE SENSOR OPERATION 
    • Ignition ON, engine OFF.
    • For Transit,
    • Access the DCU and monitor the REDUCT_TNK_P (PRESS) PID.
    • Record the REDUCT_TNK_P PID value.
    • Carry out the SCR Dosing Measurement Test on the scan tool.
    • Record the REDUCT_TNK_P PID value.
    • For all others,
    • Access the PCM and monitor the REDUCT_TNK_P (PRESS) PID.
    • Record the REDUCT_TNK_P PID value.
    • Carry out the SCR Dosing Measurement Test on the scan tool.
    • Record the REDUCT_TNK_P PID value.

    Does the REDUCT_TNK_P PID value change from the initial recorded value? 

    Yes No
    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.    		 GO to  RF3.
  3. RF3 CHECK THE REDUCTANT PRESSURE SENSOR CIRCUITS FOR AN OPEN 
    • Ignition OFF.
    • For Transit,
    • Reductant Pressure Sensor connector disconnected.
    • Reductant Dosage Control Module connector disconnected.
    • Measure the resistance between:
      (+) Reductant Pressure Sensor Connector, Harness Side (-) Reductant Dosage Control Module Connector, Harness Side
      RDP - Pin 2 RDP - Pin 60
      VREF - Pin 1 VREF - Pin 26
      SIGRTN - Pin 3 SIGRTN - Pin 81
    • For all others,
    • Reductant Pump Assembly connector disconnected.
    • PCM-E connector disconnected.
    • PCM-T connector disconnected.
    • Measure the resistance between:
      (+) Reductant Pump Assembly Connector, Harness Side (-) PCM-E Connector, Harness Side
      RDP - Pin 4 RDP - Pin 72
    • Measure the resistance between:
      (+) Reductant Pump Assembly Connector, Harness Side (-) PCM-T Connector, Harness Side
      VREF - Pin 5 VREF
      SIGRTN - Pin 3 SIGRTN

    Are the resistances less than 5 ohms? 

    Yes No
    GO to  RF4. For DTC P204E, REPAIR the open circuit.
    CARRY OUT the Selective Catalytic Reduction (SCR) System Procedure. REFER to DRIVE CYCLES . Clear the RDCM and PCM DTCs. REPEAT the self-test.
    For all others, REPAIR the open circuit. Clear the RDCM and PCM DTCs. REPEAT the selftest.
  4. RF4 CHECK THE REDUCTANT PRESSURE SENSOR CIRCUITS FOR A SHORT TO GROUND 
    • For Transit,
    • Measure the resistance between:
      (+) Reductant Pressure Sensor Connector, Harness Side (-)
      RDP - Pin 2 Ground
      VREF - Pin 1 Ground
      SIGRTN - Pin 3 Ground
    • For all others,
    • Measure the resistance between:
      (+) Reductant Pump Assembly Connector, Harness Side (-)
      RDP - Pin 4 Ground
      VREF - Pin 5 Ground
      SIGRTN - Pin 3 Ground

    Are the resistances greater than 10K ohms? 

    Yes No
    GO to  RF5. REPAIR the short circuit. Clear the RDCM and PCM DTCs. REPEAT the self-test.
  5. RF5 CHECK THE REDUCTANT PRESSURE SENSOR CIRCUITS FOR A SHORT TO VOLTAGE 
  • Ignition ON, engine OFF.
  • For Transit,
  • Measure the voltage between:
    (+) Reductant Pressure Sensor Connector, Harness Side (-)
    RDP - Pin 2 Ground
    VREF - Pin 1 Ground
    SIGRTN - Pin 3 Ground
  • For all others,
  • Measure the voltage between:
    (+) Reductant Pump Assembly Connector, Harness Side (-)
    RDP - Pin 4 Ground
    VREF - Pin 5 Ground
    SIGRTN - Pin 3 Ground

Is any voltage present? 

Yes No
REPAIR the short circuit. Clear the RDCM and PCM DTCs. REPEAT the self-test. INSTALL a new Reductant Pump assembly.
REFER to the appropriate Engine Emission Control article.
CARRY OUT the Selective Catalytic Reduction (SCR) System Procedure. REFER to DRIVE CYCLES . Clear the RDCM and PCM DTCs. REPEAT the self-test.
RENDER: 1.0x

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Stop DIY work and contact a certified mechanic immediately if any of the following apply:

  • • You smell fuel, burning insulation, or see smoke.
  • • Brakes feel soft, pull hard to one side, or make grinding noises.
  • • The engine overheats, stalls repeatedly, or misfires under load.
  • • You are missing required tools, torque specs, or safe lifting equipment.
  • • You are not confident in the next step or safety outcome.