Egr System; Dtc Troubleshooting - Honda 2004 Odyssey Service Manual

EGR System

DTC Troubleshooting

DTC P0401: EGR System Insufficient Flow
1. Reset the PCM (see page 11-4).
2. Test-drive under these conditions:
• Without any electrical load.
• Decelerate from 55 mph (88 km/h) for at least 5
seconds.
3. Check for a Temporary DTC with the scan tool
or the HDS.
Is T emporary DT C P0401 indicated?
YES Clean the intake manifold EGR port with
carburetor cleaner. Clean the passage inside the
EGR valve with carburetor cleaner, or replace the
EGR valve.
NO Intermittent failure, go to step 4.
4. Turn the ignition switch OFF.
5. Disconnect the EGR valve 6P connector.
6. Connect the battery positive terminal to EGR valve
connector terminal No. 4.
EGR VALVE 6P CONNECTOR
EGR
Terminal side of male terminals
7. Start the engine and let it idle, then connect the
battery negative terminal to EGR valve connector
terminal No. 6.
Does the engine stall or run rough?
YES Intermittent failure, system is OK at this
time.
NO Clean the intake manifold EGR port with
caburetor cleaner. Clean the passage inside the
EGR valve with carburetor cleaner, or replace the
EGR valve.
GND
DTC P1491 '99-00, '02-04 Models:
Valve Insufficient Lift
NOTE: Information marked with an asterisk ( ) applies
to '02-04 models.
1. Reset the PCM (see page 11-4).
2. Start the engine. Hold the engine at 3,000 rpm with
no load (in Park or neutral) until the radiator fan
comes on.
3. Test-drive the vehicle under load for about 10
minutes. Try to keep the engine speed in the
1,700 2,500 rpm range.
4. Check for a Temporary DTC with the scan tool or
the HDS.
Is T emporary DT C P1491 indicated?
YES Go to step 5.
NO Intermittent failure, system is OK at this time.
Check for poor connections or loose terminals at
the EGR valve and at the PCM.
5. Turn the ignition switch OFF.
6. Disconnect the EGR valve 6P connector.
7. Start the engine, and let it idle.
EGR
(cont'd)
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