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
- AZ1 CHECK FOR DIAGNOSTIC TROUBLE CODES (DTCS)
Are DTCs P0401, P0402, P042E, P04D9, P04DA, P1408, P2425, P2426, P2427, P2457, P245A, P245B, P245C, P245D or P24A5 present?
Yes No For DTCs P2425, P2426, P2427, or P245A. GO to AZ2.
For all others, GO to AZ7.For symptoms without DTCs, GO to AZ7.
For all others, RETURN to SYMPTOM CHARTS for further direction. - AZ2 CHECK THE VPWR CIRCUIT FOR AN OPEN
- Ignition OFF.
- Exhaust Gas Recirculation (EGR) Cooler Bypass Valve Solenoid connector disconnected.
- Ignition ON, engine OFF.
- Measure the voltage between:
(+) Exhaust Gas Recirculation (EGR) Cooler Bypass Valve Solenoid Connector, Harness Side (-) VPWR Ground Is the voltage greater than 10.5 V?
Yes No GO to AZ3. REPAIR the open circuit. Clear the PCM DTCs.
REPEAT the self-test. - AZ3 CHECK THE EGRCBV CIRCUIT FOR AN OPEN
- Ignition OFF.
- PCM-E connector disconnected.
- Measure the resistance between:
(+) Exhaust Gas Recirculation (EGR) Cooler Bypass Valve Solenoid Connector, Harness Side (-) PCM-E Connector, Harness Side EGRCBV EGRCBV Is the resistance less than 5 ohms?
Yes No GO to AZ4. REPAIR the open circuit. Clear the PCM DTCs.
REPEAT the self-test. - AZ4 CHECK THE EGRCBV CIRCUIT FOR A SHORT TO GROUND
- Measure the resistance between:
(+) Exhaust Gas Recirculation (EGR) Cooler Bypass Valve Solenoid Connector, Harness Side (-) EGRCBV Ground Is the resistance greater than 10K ohms?
Yes No GO to AZ5. REPAIR the short circuit. Clear the PCM DTCs.
REPEAT the self-test. - AZ5 CHECK THE EGRCBV CIRCUIT FOR A SHORT TO VOLTAGE
- Ignition ON, engine OFF.
- Measure the voltage between:
(+) Exhaust Gas Recirculation (EGR) Cooler Bypass Valve Solenoid Connector, Harness Side (-) EGRCBV Ground Is any voltage present?
Yes No REPAIR the short circuit. Clear the PCM DTCs.
REPEAT the self-test.GO to AZ6. - AZ6 CHECK THE EGR COOLER BYPASS VALVE SOLENOID FOR THE CORRECT RESISTANCE
- Ignition OFF.
- Measure the resistance between:
(+) Exhaust Gas Recirculation (EGR) Cooler Bypass Valve Solenoid Connector, Component Side (-) Exhaust Gas Recirculation (EGR) Cooler Bypass Valve Solenoid Connector, Component Side VPWR EGRCBV Is the resistance between 10 - 40 ohms?
Yes No For DTCs P2425, P2426, P2427, GO to AZ15.
For all others, GO to AZ7.INSTALL a new Exhaust Gas Recirculation (EGR) Cooler Bypass Valve solenoid. Refer to the appropriate Engine Emission Control article.
Clear the PCM DTCs. REPEAT the self-test. - AZ7 CARRY OUT A VISUAL INSPECTION NOTE: When checking the EGR cooler bypass valve actuator for sticking or binding it is normal to notice some inconsistent movement.
- Visually inspect for:
- damaged or leaking vacuum lines
- damaged EGR cooler bypass valve actuator or linkage
- damaged EGR cooler bypass valve solenoid
- Manually move the EGR cooler bypass valve actuator to check for sticking or binding.
Is a concern present?
Yes No REPAIR as necessary.
Clear the PCM DTCs. REPEAT the self-test.GO to AZ8. - Visually inspect for:
- AZ8 CHECK THE COOLING SYSTEM
- Ignition OFF.
- PCM-E connector connected.
- Exhaust Gas Recirculation (EGR) Cooler Bypass Valve Solenoid connector connected.
- Check the cooling system for a system overheating condition or a low coolant condition. Refer to the appropriate Engine Cooling, Inspection and Verification article.
Is the cooling system overheating or is a low coolant condition present?
Yes No REPAIR as necessary. REFER to the appropriate Engine Cooling, Symptom Chart to diagnose the system overheats symptom or loss of coolant symptom.
Clear the PCM DTCs. REPEAT the self-test.For F-150. GO to AZ9.
For all others, GO to AZ10. - AZ9 CHECK THE EGR FLOW THROUGH THE EGR COOLER NOTE: Verify the engine coolant temperature (ECT) is greater than 70°C (158°F) before testing (F-150). Verify the engine oil temperature (EOT) is greater than 60°C (140°F) before testing (All others).
- Ignition ON, engine running.
- Access the PCM and monitor the ECT1 (TEMP) PID.
- Access the PCM and monitor the EOT (TEMP) and EGRTC (TEMP) PIDs.
- Access the PCM and monitor the MAF (FLOW) PID.
- Access the PCM and control the VGTDC (PER) PID.
- Command the VGTDC PID to 80% (F-150) or 100% (all others).
- Access the PCM and control the RPMDSD (RPM) PID.
- Increase the RPM_DSD PID to approximately 2000 (F-150) or 1, 800 RPM (all others).
- Access the PCM and control the EGRVPDES (PER) PID.
- Command the EGRVPDES PID to 50% (F-150) or 40% (all others).
- Access the PCM and control the EGRCBV (MODE) PID.
- Command the EGRCBV PID ON, wait 5 seconds, then command the EGRCBV PID OFF.
- Monitor the MAF PID and the EGRTC PID values while commanding the EGRCBV_DSD PID ON and then OFF.
Does the MAF PID increase by less than 0.008 kg/s (8 g/s) (F-150) or 0.005 kg/s (5 g/s) (all others) and does the EGRTC PID decrease by more than 15° C (27°F) (F-150) or 25° C (45.83° F) (all others)?
Yes No The system is operating correctly at this time.
RETURN to SYMPTOM CHARTS , for further direction.GO to AZ13. - AZ10 VISUALLY CHECK THE FUNCTIONALITY OF THE EGR COOLER BYPASS VALVE NOTE: When the ignition is OFF, the EGR cooler bypass valve linkage will be fully extended.
- Ignition OFF.
- Observe the position of the EGR cooler bypass valve linkage.
- Ignition ON, engine running.
- Observe the position of the EGR cooler bypass valve linkage.
Did the EGR cooler bypass valve linkage change from fully extended to fully retracted?
Yes No GO to AZ11. For EGR cooler bypass valve linkage is always retracted. GO to AZ11.
For all others, GO to AZ13. - AZ11 CHECK FOR A STUCK OPEN EGR COOLER BYPASS VALVE SOLENOID NOTE: The EGR cooler bypass valve is normally closed with the engine OFF or when commanded to 0% duty cycle. EGR flow is directed through the EGR cooler when the EGR cooler bypass valve is closed.
- Ignition OFF.
- Exhaust Gas Recirculation (EGR) Cooler Bypass Valve Solenoid connector disconnected.
- Ignition ON, engine running.
Is the EGR cooler bypass valve linkage fully retracted?
Yes No INSTALL a new Exhaust Gas Recirculation (EGR) Cooler Bypass Valve solenoid. Refer to the appropriate Engine Emission Control article.
Clear the PCM DTCs. REPEAT the self-test.For Transit Connect, GO to AZ13.
For all others, GO to AZ12. - AZ12 CHECK THE EGR FLOW THROUGH THE EGR COOLER NOTE: Verify the engine oil temperature (EOT) is greater than 60°C (140°F) before testing.
- Exhaust Gas Recirculation (EGR) Cooler Bypass Valve Solenoid connector connected.
- Ignition ON, engine running.
- Access the PCM and monitor the EOT (TEMP) and EGRTC (TEMP) PIDs.
- Access the PCM and control the VGTDC (PER) PID.
- Command the VGTDC PID to 60%.
- Access the PCM and control the RPMDSD (RPM) PID.
- Increase the RPMDSD PID to approximately 1, 500 RPM.
- Access the PCM and control the EGRTP_CMD (PER) PID.
- Command the EGRTP_CMD to 0%.
- Access the PCM and control the EGRVPDES (PER) PID.
- Command the EGRVPDES PID to approximately 60% (F-Series Super Duty and F-650-750) or 53% (all others).
- Access the PCM and control the EGRCBV (MODE) PID.
- For F-Series Super Duty command EGRCBV to 100%, wait 5 seconds, then command EGRCBV to 0%.
- For all others command the EGRCBV PID ON, wait 5 seconds, then command the EGRCBV PID OFF.
- Monitor the MAF PID and the EGRTC PID values while commanding the EGRCBV PID from ON to OFF.
- Access the PCM and monitor the MAF (FLOW) PID.
Does the MAF PID increase by less than 0.014 kg/s (14 g/s) and does the EGRTC PID decrease by more than 28°C (50°F) (F-Series Super Duty pickup), 23°C (41°F) (F-650/F-750 and F-Series Super Duty Stripped Chassis) or 30° C (55° F) (all others)?
Yes No The system is operating correctly at this time. RETURN to SYMPTOM CHARTS , for further direction. REFER to the appropriate Engine Emission Control article, Disassembly and Assembly. INSPECT the EGR cooler bypass valve. INSPECT the EGR cooler core. REPAIR as necessary.
Clear the PCM DTCs. REPEAT the self-test. - AZ13 CHECK FOR VACUUM AT THE EGR COOLER BYPASS VALVE ACTUATOR
- Ignition OFF.
- Disconnect the EGR cooler bypass valve actuator vacuum hose.
- Connect the DSL ENG Pressure Test Kit 014-00761 or equivalent to the EGR cooler bypass valve actuator vacuum hose.
- Ignition ON, engine running.
Is 78 kPa (23 in-Hg) or greater vacuum present at the EGR cooler bypass valve actuator vacuum hose?
Yes No INSTALL a new EGR cooler bypass valve actuator. Refer to the appropriate Engine Emission Control article.
Clear the PCM DTCs. REPEAT the self-test.GO to AZ14. - AZ14 CHECK FOR VACUUM AT THE EGR COOLER BYPASS VALVE SOLENOID
- Ignition OFF.
- Disconnect the EGR cooler bypass solenoid vacuum hose from the EGR cooler bypass valve solenoid.
- Connect the DSL ENG Pressure Test Kit 014-00761 or equivalent to the bypass solenoid vacuum hose.
- Ignition ON, engine running.
Is 67.73 kPa (20 in-Hg) or greater vacuum present at the EGR cooler bypass solenoid vacuum hose?
Yes No INSTALL a new Exhaust Gas Recirculation (EGR) Cooler Bypass Valve solenoid.
Refer to the appropriate Engine Emission Control article.
Clear the PCM DTCs. REPEAT the self-test.DIAGNOSE a loss of vacuum concern. CHECK the vacuum hoses for a leak or restriction. CHECK the vacuum pump for correct operation. REPAIR as necessary.
Clear the PCM DTCs. REPEAT the self-test. - AZ15 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) , Programming the VID Block for a Replacement PCM. The system is operating correctly at this time.
The concern may have been caused by a loose or corroded connector.
NO RELATED
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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.