Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
Test Procedure
- RG1 PRELIMINARY DIAGNOSIS
Are DTCs P130E, P208A, P208B, P208C, P208D, P20E8, P20E9, P20FF, P204F, P218F, P214E, P21CB, P21CC or U040F present?
Yes No For Transit, GO to RG2.
For all others with DTC P20FF, INSTALL a new Reductant Pump Control Module. REFER to the Engine Emission Control article.
Clear the DTCs. REPEAT the self-test.
For all others, GO to RG7.RETURN to SYMPTOM CHARTS for further direction. - RG2 CHECK THE REDUCTANT PUMP MOTOR FOR INTERNAL SHORTS
- Reductant Pump Assembly connector disconnected.
- Measure the resistance between:
(+) Reductant Pump Assembly Connector, Component Side (-) Reductant Pump Assembly Connector, Component Side RDPC GND RDPC GND
Are the resistances greater than 10K ohms?
Yes No GO to RG3. INSTALL a new Reductant Pump assembly. REFER to the Engine Emission Control article. Clear the RDCM and PCM DTCs. REPEAT the self-test. - RG3 CHECK THE VPWR CIRCUIT FOR VOLTAGE NOTE: The VPWR voltage will drop soon after the ignition is turned ON. Connect the digital multimeter before turning the ignition ON.
- Ignition ON, engine OFF.
- Measure the voltage between:
(+) Reductant Pump Assembly Connector, Harness Side (-) VPWR Ground - Immediately record the voltage value on the digital multimeter.
Is the voltage greater than 10 V?
Yes No GO to RG4. REPAIR the open circuit. Clear the RDCM and PCM DTCs. REPEAT the self-test. - RG4 CHECK THE RDPC AND GND CIRCUITS FOR AN OPEN
- Ignition OFF.
- Reductant Dosage Control Module connector disconnected.
- For Transit Connect,
- Measure the resistance between:
(+) Reductant Pump Assembly Connector, Harness Side (-) Reductant Dosage Control Module Connector, Harness Side RDPC RDPC - For all others,
- Measure the resistance between:
(+) Reductant Pump Assembly Connector, Harness Side (-) Reductant Dosage Control Module Connector, Harness Side RDPC RDPC GND RDPGND
Are the resistances less than 5 ohms?
Yes No GO to RG5. For DTC P130E, REPAIR the open circuit.
CARRY OUT the Selective Catalytic Reduction (SCR) System Procedure. REFER to DRIVE CYCLES . DRIVE the vehicle until the system warning message has cleared from the instrument cluster message center. 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. - RG5 CHECK THE RDPC CIRCUIT FOR A SHORT TO GROUND
- Measure the resistance between:
(+) Reductant Pump Assembly Connector, Harness Side (-) RDPC Ground Is the resistance greater than 10K ohms?
Yes No GO to RG6. REPAIR the short circuit. Clear the RDCM and PCM DTCs. REPEAT the self-test. - RG6 CHECK THE RDPC CIRCUIT FOR A SHORT TO VOLTAGE
- Ignition ON, engine OFF.
- Measure the voltage between:
(+) Reductant Pump Assembly Connector, Harness Side (-) RDPC Ground Is any voltage present?
Yes No REPAIR the short circuit. Clear the RDCM and PCM DTCs. REPEAT the self-test. GO to RG19. - RG7 CHECK THE VOLTAGE TO THE REDUCTANT PUMP CONTROL MODULE
- Ignition OFF.
- Reductant Pump Control Module connector disconnected.
- Ignition ON, engine OFF.
- Measure the voltage between:
(+) Reductant Pump Control Module Connector, Harness Side (-) VPWR - Pin 5 Ground Is the voltage greater than 10.5 V?
Yes No GO to RG8. REPAIR the open circuit. Clear the PCM DTCs. REPEAT the self-test. - RG8 CHECK THE GND CIRCUIT FOR AN OPEN
- Measure the resistance between:
(+) Reductant Pump Control Module Connector, Harness Side (-) GND - Pin 1 Ground Is the resistance less than 5 ohms?
Yes No GO to RG9. REPAIR the open circuit. Clear the PCM DTCs. REPEAT the self-test. - RG9 CHECK THE RDPC AND RDPM CIRCUITS FOR AN OPEN
- PCM-T connector disconnected.
- Measure the resistance between:
(+) Reductant Pump Control Module Connector, Harness Side (-) PCM-T Connector, Harness Side RDPC - Pin 4 RDPC - Pin 23 RDPM - Pin 3 RDPM - Pin 29 Are the resistances less than 5 ohms?
Yes No GO to RG10. REPAIR the open circuit. Clear the PCM DTCs. REPEAT the self-test. - RG10 CHECK THE RDPC AND RDPM CIRCUITS FOR A SHORT TO GROUND
- Measure the resistance between:
(+) Reductant Pump Control Module Connector, Harness Side (-) RDPC - Pin 4 Ground RDPM - Pin 3 Ground Are the resistances greater than 10K ohms?
Yes No GO to RG11. REPAIR the short circuit. Clear the PCM DTCs. REPEAT the self-test. - RG11 CHECK THE RDPC AND RDPM CIRCUITS FOR A SHORT TO VOLTAGE
- Ignition ON, engine OFF.
- Measure the voltage between:
(+) Reductant Pump Control Module Connector, Harness Side (-) RDPC - Pin 4 Ground RDPM - Pin 3 Ground Is any voltage present?
Yes No REPAIR the short circuit. Clear the PCM DTCs. REPEAT the self-test. GO to RG12. - RG12 CHECK THE REDUCTANT PUMP MOTOR FOR INTERNAL SHORTS
- Ignition OFF.
- Reductant Pump Assembly connector disconnected.
- Measure the resistance between:
(+) Reductant Pump Assembly Connector, Component Side (-) Reductant Pump Assembly Connector, Component Side RDPAP GND RDPBP GND RDPCP GND RDPAP GND RDPBP GND RDPCP GND Are the resistances greater than 10K ohms?
Yes No GO to RG13. INSTALL a new Reductant Pump assembly. REFER to the Engine Emission Control article.
Clear the PCM DTCs. REPEAT the self-test. - RG13 CHECK THE REDUCTANT PUMP MOTOR RESISTANCE
- Measure the resistance between:
(+) Reductant Pump Assembly Connector, Component Side (-) Reductant Pump Assembly Connector, Component Side RDPAP RDPBP RDPAP RDPCP RDPBP RDPCP Are the resistances between 0.36 - 0.42 ohms?
Yes No GO to RG14. INSTALL a new Reductant Pump assembly. REFER to the Engine Emission Control article.
Clear the PCM DTCs. REPEAT the self-test. - RG14 CHECK THE REDUCTANT PUMP MOTOR DRIVE CIRCUITS FOR AN OPEN
- Measure the resistance between:
(+) Reductant Pump Control Module Connector, Harness Side (-) Reductant Pump Assembly Connector, Harness Side RDPAP - Pin 6 RDPAP RDPBP - Pin 2 RDPBP RDPCP - Pin 7 RDPCP Are the resistances less than 5 ohms?
Yes No GO to RG15. REPAIR the open circuit. Clear the PCM DTCs. REPEAT the self-test. - RG15 CHECK THE REDUCTANT PUMP MOTOR DRIVE CIRCUITS FOR A SHORT TO GROUND
- Measure the resistance between:
(+) Reductant Pump Assembly Connector, Harness Side (-) RDPAP Ground RDPBP Ground RDPCP Ground Are the resistances greater than 10K ohms?
Yes No For DTCs P208A, P208B, P208C or P208D, GO to RG16.
For all others, GO to RG17.REPAIR the short circuit. Clear the PCM DTCs. REPEAT the self-test. - RG16 CHECK FOR THE RDPAP, RDPBP AND RDPCP CIRCUITS SHORTED TOGETHER
- Ignition OFF.
- Reductant Pump Assembly connector disconnected.
- Measure the resistance between:
(+) Reductant Pump Assembly Connector, Harness Side (-) Reductant Pump Assembly Connector, Harness Side RDPAP RDPBP RDPAP RDPCP RDPBP RDPCP Are the resistances greater than 10K ohms?
Yes No INSTALL a new Reductant Pump assembly. REFER to the Engine Emission Control article.
Clear the PCM DTCs. REPEAT the self-test.REPAIR as necessary.
Clear the PCM DTCs. REPEAT the self-test. - RG17 CHECK THE REDUCTANT PUMP MOTOR DRIVE CIRCUITS FOR A SHORT TO VOLTAGE
- Ignition ON, engine OFF.
- Measure the voltage between:
(+) Reductant Pump Assembly Connector, Harness Side (-) RDPAP Ground RDPBP Ground RDPCP Ground Is any voltage present?
Yes No REPAIR the short circuit. Clear the PCM DTCs. REPEAT the self-test. GO to RG18. - RG18 INTERMITTENT CHECK
- Measure the resistance between:
(+) Reductant Pump Control Module Connector, Harness Side (-) PCM-T Connector, Harness Side RDPC - Pin 4 RDPC - Pin 23 RDPM - Pin 3 RDPM - Pin 29 - While monitoring the resistance measurement, wiggle, shake, and bend small sections of the wiring harness while working from the reductant pump control module to the PCM.
- Measure the resistance between:
(+) Reductant Pump Control Module Connector, Harness Side (-) Reductant Pump Assembly Connector, Harness Side RDPAP - Pin 6 RDPAP RDPBP - Pin 2 RDPBP RDPCP - Pin 7 RDPCP - While monitoring the resistance measurement, wiggle, shake, and bend small sections of the wiring harness while working from the reductant pump control module to the reductant pump assembly.
Is a concern present?
Yes No REPAIR as necessary.
Clear the PCM DTCs. REPEAT the self-test.For DTC U040F, INSTALL a new Reductant Pump Control Module. REFER to the Engine Emission Control article.
Clear the PCM DTCs. REPEAT the self-test.
For all others, GO to RG19. - Measure the resistance between:
- RG19 CHECK FOR CORRECT REDUCTANT PUMP OPERATION
- For Transit,
- Reductant Pump Assembly connector connected.
- Reductant Dosage Control Module connector connected.
- Ignition ON, engine OFF.
- Access the DCU and monitor the REDUCT_TNK_P (PRESS) PID.
- Carry out the SCR Leak Test on the scan tool to pressurize the system.
- For all others,
- PCM-T connector connected.
- Reductant Pump Assembly connector connected.
- Reductant Pump Control Module connector connected.
- Ignition ON, engine OFF.
- Access the PCM and monitor the REDUCT_TNK_P (PRESS) PID.
- Carry out the SCR Leak Test on the scan tool to pressurize the system.
Does the REDUCT_TNK_P PID value increase to greater than 65 psi?
Yes No The system is operating correctly at this time.
The concern may have been caused by a loose or corroded connector.INSTALL a new Reductant Pump assembly.
REFER to the Engine Emission Control article.
Clear the RDCM and PCM DTCs. REPEAT the self-test.
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When to See a Mechanic
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.