LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Ford >> 2021 >> F-150 Raptor >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls - Pinpoint Tests (Diesel) >> Pinpoint Tests RF: Reductant Pressure Sensor >> Test Procedure
April 5, 2026: LEMON Manuals is launched! Read the announcement.

Test Procedure

  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.
    • 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.
    • Reductant Pump Assembly connector disconnected.
    • PCM-T connector disconnected.
    • Measure the resistance between:
    (+) Reductant Pump Assembly Connector, Harness Side (-) PCM-T Connector, Harness Side
    RDP - Pin 4 RDP - Pin 40
    VREF - Pin 5 VREF - Pin 68
    SIGRTN - Pin 3 SIGRTN - Pin 55

    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 self-test.
  4. RF4 CHECK THE REDUCTANT PRESSURE SENSOR CIRCUITS FOR A SHORT TO GROUND 
    • 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.
    • 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 GPCM and PCM DTCs. REPEAT the self-test.
scientia non olet · About LEMON Manuals