DTC P0401: EGR Insufficient Flow

NOTE: If DTC P1491 is set when DTC P0401 is set, trouble shoot DTC P1491 first and perform PCM reset procedure. See PCM RESET PROCEDURE/CLEARING DTCS in SELF-DIAGNOSTICS - INTRODUCTION article. Recheck for DTC P0401.

NOTE: DTC P0401 is set and MIL illuminated when malfunction has been detected during 2 consecutive trips.

Perform PCM reset procedure. See PCM RESET PROCEDURE/CLEARING DTCS in SELF-DIAGNOSTICS - INTRODUCTION article. Connect SCS Service Connector to 2-pin service check connector. See Figure . Test drive vehicle without any electrical load. Decelerate vehicle from 55 MPH for at least 5 seconds. If DTC P0401 is not indicated, problem is intermittent. System is okay at this time. If DTC P0401 is indicated, clean intake manifold EGR port with carburetor cleaner. Clean passage inside EGR valve with carburetor cleaner or replace valve.