DTC Troubleshooting

DTC P0400: EGR System Leak Detected

NOTE: Before you troubleshoot, record all freeze data and any on-board snapshot, and review the general troubleshooting information.

1. Check for a loose or damaged EGR pipe.

Is the EGR pipe OK?

YES - Go to step 2.

NO - Reconnect or replace the EGR pipe, then go to step 7.

2. Start the engine. Hold the engine speed at 3,000 rpm without load (A/T 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 °F (70 °C)
- A/T in D, M/T in 4th
- Vehicle speed at 25 mph (40 km/h) for 5 minutes or more
- Maintain the vehicle speed at 32 mph (50 km/h) for 5 minutes or more with cruise control set

4. Monitor the OBD STATUS for DTC P0400 in the DTCs MENU with the HDS.

Does the screen indicate FAILED?

YES - Go to step 5.

NO - If the screen indicates PASSED, intermittent failure, the system is OK at this time. Check for exhaust gas leakage between EGR pipe and EGR valve. If the screen indicates NOT COMPLETED, go to step 3 and recheck.

5. Turn the ignition switch to LOCK (0).
6. Replace the EGR valve.
7. Turn the ignition switch to ON (II).
8. Reset the ECM/PCM with the HDS.
9. Do the ECM/PCM idle learn procedure. Programming and Relearning
10. Test-drive under these conditions:
- Engine coolant temperature (ECT SENSOR 1) above 158 °F (70 °C)
- A/T in D, M/T in 4th
- Vehicle speed at 25 mph (40 km/h) for 5 minutes or more
- Maintain the vehicle speed at 32 mph (50 km/h) for 5 minutes or more with cruise control set

11. Check for Temporary DTCs or DTCs with the HDS.

Is DTC P0400 indicated?

YES - Check for leakage between EGR pipe and EGR valve exhaust gas, then go to step 1.

NO - Go to step 12.

12. Monitor the OBD STATUS for DTC P0400 in the DTCs MENU with the HDS.

Does the screen indicate PASSED?

YES - Troubleshooting is complete. If any other Temporary DTCs or DTCs were indicated in step 11, go to the indicated DTCs troubleshooting.

NO - If the screen indicates FAILED, check for leakage between EGR pipe and EGR valve exhaust gas, then go to step 1. If the screen indicates NOT COMPLETED, go to step 10.