DTC P0404

DTC P0404  : EGR Valve Circuit Range/Performance Problem

DTC (PGM-FI)

1. Problem verification

   -1. Turn the vehicle to the ON mode.

   -2. Clear the DTC with the HDS.

   -3. Start the engine. Hold the engine speed at 3000 RPM without load (in P or N) until the radiator fan comes on, then let it idle.

   -4. Do the EGR TEST with the HDS.

   EGR TEST

   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

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

   -2. Disconnect the following connector.

   EGR 5P connector

   -3. At the EGR valve side, measure the resistance between test points 1 and 2.

   Test condition	Vehicle OFF (LOCK) 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)

   Courtesy of HONDA, U.S.A., INC.

   Is there 100 kΩ or more?

   YES 

   Replace the EGR valve , then do the repair verification.

   NO 

   Go to step 3.

3. 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
   	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)

   Courtesy of HONDA, U.S.A., INC.

   Is there 100 kΩ or more?

   YES 

   Replace the EGR valve , then do the repair verification.

   NO 

   Go to step 4.

4. Open wire check (E-EGR PG/PG line)

   -1. Check for continuity between test point 1 and 2.

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

   Courtesy of HONDA, U.S.A., INC.

   Is there continuity?

   YES 

   The E-EGR PG/PG wire is OK. Go to step 5.

   NO 

   Repair an open in the E-EGR PG/PG wire between the EGR valve and G101, then do the repair verification.

5. 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 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

   Courtesy of HONDA, U.S.A., INC.

   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)

   -1. Check for continuity between test points 1 and 2.

   Test condition	Vehicle OFF (LOCK) 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)

   Courtesy of HONDA, U.S.A., INC.

   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

   -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 .

   Reset PCM

   -7. Do the PCM idle learn procedure.

   -8. Do the EGR TEST with the HDS.

   EGR TEST

   Is the result OK?

   YES 

   The failure is not duplicated. Do the repair verification.

   NO 

   Go to step 8.

8. 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 .

   Reset PCM

   -5. Do the PCM idle learn procedure.

   -6. Do the EGR TEST with the HDS.

   EGR TEST

   Is the result OK?

   YES 

   Replace the original EGR valve , then do the repair verification.

   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.

9. Repair verification (OBD STATUS check)

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

   -2. Reconnect all connectors.

   -3. Exit the SCS mode with the HDS.

   -4. Turn the vehicle to the ON mode.

   -5. Reset the PCM with the HDS .

   Reset PCM

   -6. Do the PCM idle learn procedure .

   -7. Do the EGR TEST with the HDS.

   EGR TEST

   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

   DTC (PGM-FI)

   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 conditions until a result comes on.

   OUT OF CONDITION

   Meet the test conditions, and check the OBD STATUS again.