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.
P0400-EGR System Performance: Notes
- When Monitored : A constant engine speed between 900 and 1700 RPM and no other EGR or MAP sensor faults.
- Set Condition : The PCM commands the EGR valve to open. The MAP sensor value must drop by a minimum of 54 mbar (1.6 in. Hg) when EGR is commanded open or a fault is set.
| Possible Causes |
| EGR SOLENOID CONTROL CIRCUIT OPEN |
| EGR SOLENOID CONTROL CIRCUIT SHORT TO GROUND |
| EGR SOLENOID CONTROL CIRCUIT SHORT TO VOLTAGE |
| FUSED ENGINE CONTROL RELAY OUTPUT CIRCUIT OPEN |
| EGR SOLENOID |
| EGR VALVE |
| POWERTRAIN CONTROL MODULE |
For a complete Powertrain Control Module Circuit Diagram, refer to SCHEMATICS AND DIAGRAMS .
Use the Manual With the Right Hardware
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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.
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