P0401

DTC P0401: Insufficient Flow Detected in EGR System

1. Reset the ECM/PCM.
2. With the Honda PGM Tester connected, test-drive under the following conditions.
- Without any electrical load.
- Decelerate from 55 mph (88 km/h) for at least 5 seconds.

Is Temporary DTC 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 3.

3. Turn the ignition switch OFF.
4. Disconnect the EGR valve 6P connector.




5. Connect the battery positive terminal to EGR valve connector terminal No.4.
6. Start the engine and let it idle, then connect the battery negative terminal No.6.

Did the engine stall or run rough?

YES - Intermittent failure, system is OK at this time.

NO - Clean the intake manifold EGR port with carburetor cleaner. Clean the passage inside the EGR valve with carburetor cleaner or replace the EGR valve.