DTC Troubleshooting: P0400
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.

DTC Description
Confirmed DTC
Pending DTC
Freeze Frame
P0400 EGR System Leak Detected
      

1.
EGR pipe visual check:

EGR pipe visual check
?1.
Check for a loose or damaged EGR pipe.

Is the EGR pipe OK?

     
YES
     
     
     
Go to step 2.
     
NO
     
     
     
2.
Problem verification:

Problem verification
?1.
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.

?2.
Test-drive under these conditions:
Engine coolant temperature (ECT SENSOR 1) above 158 °F (70 °C)
A/T in D, M/T in 4th
Drive the vehicle at 25 mph (40 km/h) for 5 minutes or more
Maintain then vehicle speed at 26 mph (41 km/h) and the engine speed between 1,500?3,000 rpm (M/T: 1,700 - 2,900 rpm) for 10 seconds or more with cruise control set

Signal
Current conditions
Values
Unit
ECT SENSOR 1
    
VEHICLE SPEED
    
ENGINE SPEED
    

?3.
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 HDS indicates NOT COMPLETED, go to step 2-2 and recheck.
Repair verification (OBD STATUS check):

?1.
Press the engine start/stop button to select the ON mode.

?2.
Reset the PCM with the HDS.


?3.
Do the PCM idle learn procedure.

?4.
Test-drive under these conditions:
Engine coolant temperature (ECT SENSOR 1) above 158 °F (70 °C)
A/T in D, M/T in 4th
Drive the vehicle at 25 mph (40 km/h) for 5 minutes or more
Maintain then vehicle speed at 26 mph (41 km/h) and the engine speed between 1,500?3,000 rpm (M/T: 1,700 - 2,900 rpm) for 10 seconds or more with cruise control set

Signal
Current conditions
Values
Unit
ECT SENSOR 1
    
VEHICLE SPEED
    
ENGINE SPEED
    

?5.
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 PASSED, FAILED, or NOT COMPLETED?

     
PASSED
     
     
     
Troubleshooting is complete. If any other Pending or Confirmed DTCs were indicated, go to the indicated DTC's troubleshooting.?
     
FAILED
     
     
     
Go to step 1 and recheck.
     
NOT COMPLETED
     
     
     
Check the OBD STATUS again.