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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. RF1 PRELIMINARY DIAGNOSIS 

    Are DTCs P204B, P204C or P204D present? 

    Yes No
    For DTC P204B, GO to  RF2.
    For DTCs P204C or P204D, GO to  RF3.    		 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. 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. INSTALL a new Reductant Pump assembly. REFER to the Engine Emission Control article.
    Clear the PCM DTCs. REPEAT the self-test.
  3. RF3 CHECK THE REDUCTANT PRESSURE SENSOR CIRCUITS FOR AN OPEN 
    • Ignition OFF.
    • Reductant Pressure Sensor connector disconnected.
    • PCM-T connector disconnected.
    • Measure the resistance between:
      (+) Reductant Pressure Sensor Connector, Harness Side (-) PCM-T Connector, Harness Side
      RDP - Pin 2 RDP - Pin 35
      VREF - Pin 1 VREF - Pin 1
      SIGRTN - Pin 3 SIGRTN - Pin 43

    Are the resistances less than 5 ohms? 

    Yes No
    GO to  RF4. REPAIR the open circuit. Clear the PCM DTCs.
    REPEAT the self-test.
  4. RF4 CHECK THE REDUCTANT PRESSURE SENSOR CIRCUITS FOR A SHORT TO GROUND 
    • Measure the resistance between:
      (+) PCM-T Connector, Harness Side (-)
      RDP - Pin 35 Ground
      VREF - Pin 1 Ground
      SIGRTN - Pin 43 Ground

    Are the resistances greater than 10K ohms? 

    Yes No
    GO to  RF5. REPAIR the short circuit. Clear the 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:
      (+) PCM-T Connector, Harness Side (-)
      RDP - Pin 35 Ground
      VREF - Pin 1 Ground
      SIGRTN - Pin 43 Ground

    Is any voltage present? 

    Yes No
    REPAIR the short circuit. Clear the PCM DTCs.
    REPEAT the self-test.    		 GO to  RF6.
  6. RF6 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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