DTC Troubleshooting

DTC Troubleshooting: P0400

DTC P0400:

EGR System Leak Detected
(J35A7 engine ('08-10 models))

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

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 Service and Repair, then go to step 7.

2. Start the engine. Hold the engine speed at 3,000 rpm without load (in P or N) 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)
- Transmission in D
- Vehicle speed at 25 mph (40 km/h) for 5 minutes or more
- Drive at a steady speed about 26 mph (41 km/h) or more (the engine speed between 1,500-3,000 rpm) for 10 seconds or more

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 the EGR pipe and the 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 EGR Valve Replacement (J35A7).

7. Turn the ignition switch to ON (II).

8. Reset the PCM with the HDS.

9. Do the PCM idle learn procedure PCM Idle Learn Procedure.

10. Test-drive under these conditions:

- Engine coolant temperature (ECT SENSOR 1) above 158 °F (70 °C)
- Transmission in D
- Vehicle speed at 25 mph (40 km/h) for 5 minutes or more
- Drive at a steady speed about 26 mph (41 km/h) or more (the engine speed between 1,500-3,000 rpm) for 10 seconds or more

11. Check for Pending or Confirmed DTCs with the HDS.

Is DTC P0400 indicated?

YES -

Check for exhaust gas leakage between the EGR pipe and the EGR valve, 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 Pending or Confirmed DTCs were indicated in step 11, go to the indicated DTC's troubleshooting.�

NO -

If the screen indicates FAILED, check for exhaust gas leakage between the EGR pipe and the EGR valve, then go to step 1. If the screen indicates NOT COMPLETED, go to step 10.