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.
DTC P0400
DTC P0400 : EGR System Leak Detected
NOTE: Before you troubleshoot, review the general troubleshooting information .
| DTC Description | Confirmed DTC | Pending DTC | Freeze Frame |
|---|---|---|---|
| P0400 EGR System Leak Detected |
DTC (PGM-FI)
- EGR pipe visual check
-1. Check for a loose or damaged EGR pipe.
Is the EGR pipe OK?
YES
Go to step 2.
NO
- Problem verification
-1. Start the engine.
-2. Hold the engine speed at 3, 000 rpm without load (CVT in P or N, M/T in neutral) until the radiator fan comes on, then let it idle.
-3. Test-drive under these conditions:
- Engine coolant temperature (ECT SENSOR 1) above 158 deg. F (70 deg. C)
- CVT in D, M/T in 4th
- Drive the vehicle below 25 mph (40 km/h) for 5 minutes or more
- Maintain the vehicle speed at 26 mph (41 km/h) or more and the engine speed between 1, 500-4, 000 rpm for 10 seconds or more with cruise control set
Signal Current conditions Values Unit ECT SENSOR 1 VEHICLE SPEED ENGINE SPEED -4. Monitor the OBD STATUS for DTC P0400 in the DTCs MENU with the HDS.
DTC Description OBD STATUS P0400 EGR System Leak Detected Does the HDS indicate FAILED?
YES
NO
If the HDS indicates PASSED, intermittent failure, the system is OK at this time. Check for leakage between the EGR pipe and the EGR valve. If the freeze data/on-board snapshot of this DTC is recorded, try to reproduce the failure under the same conditions with the freeze data/on-board snapshot . If the HDS indicates NOT COMPLETED, go to step 2-3 and recheck.
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.