DTC Troubleshooting: P0404
DTC P0404: EGR Valve Circuit Range/Performance Problem
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
P0404 EGR Valve Circuit Range/Performance Problem
      

1.
Problem verification:

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

?2.
Clear the DTC with the HDS.


?3.
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.

?4.
Do the EGR TEST with the HDS.

  

Is the result OK?

     
YES
     
     
     
Intermittent failure, the system is OK at this time. Clean any carbon build-up on the EGR valve with throttle plate cleaner.?
     
NO
     
     
     
Failure is duplicated. Go to step 2.
2.
EGR valve position sensor internal circuit check:

EGR valve position sensor internal circuit check
?1.
Press the engine start/stop button to select the OFF mode.

?2.
Disconnect the following connector.

?3.
At the EGR valve side, measure the resistance between test points 1 and 2.
Test condition
OFF mode
 
EGR 5P connector: disconnected
Test circuit
EGRL, SG1
Test point 1
EGR valve 5P connector No. 3 (EGR valve side)
Test point 2
EGR valve 5P connector No. 4 (EGR valve side)


Is there 100 k? or more?

     
YES
     
     
     
     
NO
     
     
     
Go to step 3.
3.
EGR valve internal circuit check:

EGR valve internal circuit check
?1.
At the EGR valve side, measure the resistance between test point 1 and 2.
Test condition
OFF mode
EGR 5P connector: disconnected
Test circuit
EGRL, VCC1
Test point 1
EGR valve 5P connector No. 2 (EGR valve side)
Test point 2
EGR valve 5P connector No. 4 (EGR valve side)


Is there 100 k? or more?

     
YES
     
     
     
     
NO
     
     
     
Go to step 4.
4.
Open wire check (PG2 line):

Open wire check (PG2 line)
?1.
Check for continuity between test point 1 and 2.
Test condition
OFF mode
EGR 5P connector: disconnected
Test circuit
PG
Test point 1
EGR valve 5P connector No. 1 (BLK)
Test point 2
Body ground


Is there continuity?

     
YES
     
     
     
The PG wire is OK. Go to step 5.
     
NO
     
     
     
Repair an open in the PG wire between the EGR valve and G101, then do the repair verification.
5.
Shorted wire check (E EGR line):

Shorted wire check (E EGR line)
?1.
Jump the SCS line with the HDS.


?2.
Disconnect the following connector.

?3.
Check for continuity between test points 1 and 2.
Test condition
OFF mode
EGR 5P connector: disconnected
PCM connector C (51P): disconnected
Test circuit
E EGR
Test point 1
PCM connector C (51P) No. 13 (PUR)
Test point 2
Body ground


Is there continuity?

     
YES
     
     
     
Repair a short in the E EGR wire between the PCM (C13) and the EGR valve, then do the repair verification.
     
NO
     
     
     
The E EGR wire is not shorted. Go to step 6.
6.
Open wire check (E EGR line):

Open wire check (E EGR line)
?1.
Check for continuity between test points 1 and 2.
Test condition
OFF mode
EGR 5P connector: disconnected
PCM connector C (51P): disconnected
Test circuit
E EGR
Test point 1
EGR valve 5P connector No. 5 (PUR)
Test point 2
PCM connector C (51P) No. 13 (PUR)


Is there continuity?

     
YES
     
     
     
The E EGR wire is OK. Go to step 7.
     
NO
     
     
     
Repair an open in the E EGR wire between the PCM (C13) and the EGR valve, then do the repair verification.
7.
EGR port and passage check:

EGR port and passage check
?1.
Remove the EGR valve.

?2.
Clean the intake manifold EGR port with throttle plate cleaner. Also, clean the passage inside the EGR valve with throttle plate cleaner.

?3.
Install the EGR valve.

?4.
Reconnect all connectors.

?5.
Press the engine start/stop button to select the ON mode.

?6.
Reset the PCM with the HDS.


?7.
Do the PCM idle learn procedure.

?8.
Do the EGR TEST with the HDS.

  

Is the result OK?

     
YES
     
     
     
The failure is not duplicated. Do the repair verification.
     
NO
     
     
     
Go to step 8.
8.
EGR valve check (substitution):

EGR valve check (substitution)
?1.
Substitute a known-good EGR valve.

?2.
Reconnect the EGR valve 5P connector.

?3.
Press the engine start/stop button to select the ON mode.

?4.
Reset the PCM with the HDS.


?5.
Do the PCM idle learn procedure.

?6.
Do the EGR TEST with the HDS.

  

Is the result OK?

     
YES
     
     
     
     
NO
     
     
     
The EGR valve is OK. Update the PCM if it does not have the latest software, or substitute a known-good PCM, then do the repair verification.
Repair verification (OBD STATUS check):

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

?2.
Reconnect all connectors.

?3.
Exit the SCS mode with the HDS.


?4.
Press the engine start/stop button to select the ON mode.

?5.
Reset the PCM with the HDS.


?6.
Do the PCM idle learn procedure.

?7.
Do the EGR TEST with the HDS.

  

?8.
Monitor the OBD STATUS for DTC P0404 in the DTCs MENU with the HDS.
DTC Description
OBD STATUS
P0404 EGR Valve Circuit Range/Performance Problem
  


Does the HDS indicate PASSED, FAILED, EXECUTING, or OUT OF CONDITION?

     
PASSED
     
     
     
Troubleshooting is complete. If the PCM was substituted, replace the original PCM. If any other Pending or Confirmed DTCs are indicated, go to the indicated DTC's troubleshooting.?
     
FAILED
     
     
     
Go to step 1 and recheck. If the PCM was updated, substitute a known-good PCM, then check the OBD STATUS again.
     
EXECUTING
     
     
     
Keep the test condition until a result comes on.
     
OUT OF CONDITION
     
     
     
Meet the test condition, and check the OBD STATUS again.