DTC Troubleshooting: P0404

DTC P0404: EGR Valve Circuit Range/Performance Problem

NOTE: Before you troubleshoot, review the general troubleshooting information.

DTC Description	Confirmed DTC	Pending DTC	Freeze Frame
P0404 EGR Valve Circuit Range/Performance Problem

Problem verification:

Problem verification

?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

Intermittent failure, the system is OK at this time. Clean any carbon build-up on the EGR valve with throttle plate cleaner. 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.?


	NO

Failure is duplicated. Go to step 2.

EGR valve position sensor internal circuit check:

EGR valve position sensor internal circuit check

?1.	Turn the vehicle to the OFF (LOCK) mode.

?2.

Disconnect the following connector.

EGR valve 5P connector

?3.

At the EGR valve side, measure the resistance between test points 1 and 2.

Test condition	Vehicle OFF (LOCK) mode
	EGR valve 5P connector: disconnected
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

Replace the EGR valve.?


	NO

Go to step 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	Vehicle OFF (LOCK) mode
Test condition	EGR valve 5P connector: disconnected
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

Replace the EGR valve.?


	NO

Go to step 4.

Open wire check (PG3 line):

Open wire check (PG3 line)

?1.

Check for continuity between test point 1 and 2.

Test condition	Vehicle OFF (LOCK) mode
Test condition	EGR valve 5P connector: disconnected
Test point 1	EGR valve 5P connector No. 1
Test point 2	Body ground

Is there continuity?


	YES

The PG3 wire is OK. Go to step 5.


	NO

Repair an open in the PG3 wire between the EGR valve and G101.?

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.

PCM connector C (51P)

?3.

Check for continuity between test points 1 and 2.

Test condition	Vehicle OFF (LOCK) mode
	EGR valve 5P connector: disconnected
	PCM connector C (51P): disconnected
Test point 1	PCM connector C (51P) No. 4
Test point 2	Body ground

Is there continuity?


	YES

Repair a short in the E-EGR wire between the PCM (C4) and the EGR valve.?


	NO

The E-EGR wire is not shorted. Go to step 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	Vehicle OFF (LOCK) mode
	EGR valve 5P connector: disconnected
	PCM connector C (51P): disconnected
Test point 1	EGR valve 5P connector No. 5
Test point 2	PCM connector C (51P) No. 4

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 (C4) and the EGR valve.?

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.	Turn the vehicle to 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.?


	NO

Go to step 8.

EGR valve check (substitution):

EGR valve check (substitution)

?1.	Substitute a known-good EGR valve.

?2.

Reconnect the following connector.

EGR valve 5P connector

?3.	Turn the vehicle to 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

Replace the original EGR valve.?


	NO

The EGR valve is OK. Update the PCM if it does not have the latest software, or substitute a known-good PCM, then recheck. If DTC P0404 goes away and the PCM was updated, troubleshooting is complete. If DTC P0404 goes away and the PCM was substituted, replace the original PCM.?