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
2021 Ford Edge SE, 4WDSECTION Test Procedure
WARNING: This page is about a different car, the 2020 Ford F-550 Super Duty, 2020 Ford F-450 Super Duty, 2020 Ford F-350 Super Duty, 2020 Ford F-250 Super Duty, and 2020 Ford F-150. However, it is still accessible from the selected car via links, so may be relevant.
- RK1 PRELIMINARY DIAGNOSIS
Are DTCs P202D, P202E, P2047, P2048, P2049, P204F, P2054, P2055, P208E, P20FE, P218F, P249D or P249E present?
Yes No For DTCs P249D or P249E, GO to RK9.
For DTCs P202D, P204F, P208E or P218F, GO to RK7.
For all others, GO to RK2.RETURN to SYMPTOM CHARTS for further direction. - RK2 CHECK THE REDUCTANT INJECTOR SOLENOID RESISTANCE
- Ignition OFF.
- Reductant Injector Solenoid connector disconnected.
- Measure the resistance between:
(+) Reductant Injector Solenoid Connector, Component Side (-) Reductant Injector Solenoid Connector, Component Side RDINJPWR RDINJGND
Is the resistance between 11 - 13 ohms?
Yes No GO to RK3. For F-650/F-750 with DTC P202E, INSTALL a new Reductant Injector solenoid.
REFER to the Engine Emission Control article. CARRY OUT the Selective Catalytic Reduction (SCR) System Procedure. REFER to DRIVE CYCLES .
Clear the PCM DTCs. REPEAT the self-test.
For all others, INSTALL a new Reductant Injector solenoid.
REFER to the Engine Emission Control article. Clear the RDCM and PCM DTCs. REPEAT the self-test. - RK3 CHECK THE REDUCTANT INJECTOR CIRCUITS FOR AN OPEN
- For Transit and Transit Connect,
- Reductant Dosage Control Module connector disconnected.
- Measure the resistance between:
(+) Reductant Injector Solenoid Connector, Harness Side (-) Reductant Dosage Control Module Connector, Harness Side RDINJPWR RDINJPWR RDINJGND RDINJGND - For all others,
- PCM-T connector disconnected.
- Measure the resistance between:
(+) Reductant Injector Solenoid Connector, Harness Side (-) PCM-T Connector, Harness Side RDINJPWR RDINJPWR RDINJGND RDINJGND
Are the resistances less than 5 ohms?
Yes No GO to RK4. For F-650/F-750 with DTC P202E, REPAIR the open circuit.
CARRY OUT the Selective Catalytic Reduction (SCR) System Procedure. REFER to DRIVE CYCLES .
Clear the PCM DTCs. REPEAT the self-test.
For all others, REPAIR the open circuit. Clear the RDCM and PCM DTCs. REPEAT the self-test. - RK4 CHECK THE REDUCTANT INJECTOR CIRCUITS FOR A SHORT TO GROUND
- Measure the resistance between:
(+) Reductant Injector Solenoid Connector, Harness Side (-) RDINJPWR Ground RDINJGND Ground
Are the resistances greater than 10K ohms?
Yes No GO to RK5. REPAIR the short circuit. Clear the RDCM and PCM DTCs. REPEAT the self-test. - Measure the resistance between:
- RK5 CHECK THE REDUCTANT INJECTOR CIRCUITS FOR A SHORT TO VOLTAGE
- Ignition ON, engine OFF.
- Measure the voltage between:
(+) Reductant Injector Solenoid Connector, Harness Side (-) RDINJPWR Ground RDINJGND Ground
Is any voltage present?
Yes No REPAIR the short circuit. Clear the RDCM and PCM DTCs. REPEAT the self-test. GO to RK6. - RK6 CHECK FOR THE REDUCTANT INJECTOR CIRCUITS SHORTED TOGETHER
- Measure the resistance between:
(+) Reductant Injector Solenoid Connector, Harness Side (-) Reductant Injector Solenoid Connector, Harness Side RDINJPWR RDINJGND
Is the resistance greater than 10K ohms?
Yes No For Transit and Transit Connect, GO to RK10.
For all others, GO to RK11.REPAIR the short circuit. Clear the RDCM and PCM DTCs. REPEAT the self-test. - Measure the resistance between:
- RK7 CARRY OUT THE SCR DOSING MEASUREMENT TEST NOTE: Verify there are no low diesel exhaust fluid warnings on the message center. Fill the reductant tank as needed.
RENDER: 1.0x
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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.