DTC Troubleshooting: P0401
DTC P0401: EGR Insufficient Flow
NOTE: Before you troubleshoot, review the general troubleshooting information.

DTC Description
Confirmed DTC
Pending DTC
Freeze Frame
P0401 EGR Insufficient Flow
     

1.
EGR valve check:

EGR valve check
?1.
Turn the vehicle to the ON mode.

?2.
Clear the DTC with the HDS.


?3.
Start the engine.

?4.
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.

?5.
Do the EGR TEST with the HDS.

  

Is the result OK?

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

Problem verification
?1.
Test-drive under these conditions:
Engine coolant temperature (ECT SENSOR 1) above 158 °F (70 °C)
CVT in D, M/T in 4th
Drive the vehicle at a steady speed between 15?75 mph (24?120 km/h) for at least 5 seconds
Drive the vehicle at a steady speed between 55?75 mph (90?120 km/h) for at least 10 seconds
During the drive, decelerate (with the throttle fully closed) for 4 seconds

Signal
Current conditions
Values
Unit
ECT SENSOR 1
    
VEHICLE SPEED
    

?2.
Monitor the OBD STATUS for DTC P0401 in the DTCs MENU with the HDS.
DTC Description
OBD STATUS
P0401 EGR Insufficient Flow
 

Does the HDS indicate FAILED?

     
YES
     
     
     
Clean the intake manifold EGR port with throttle plate cleaner. Also clean the passage inside the EGR valve with throttle plate cleaner.?
     
NO
     
     
     
If the HDS indicates PASSED, intermittent failure, the system is OK at this time. Check for poor connections or loose terminals at the EGR valve and the PCM. 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 EXECUTING, keep driving until a result comes on. If the HDS indicates OUT OF CONDITION, meet the test conditions and recheck.?