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.
   • 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?