DTC P0401: EGR System - Insufficient Flow Detected
WARNING: This page is about a different car, the 2000 Acura 3.2TL. However, it is still accessible from the selected car via links, so may be relevant.
- Perform PCM reset procedure. See PCM RESET PROCEDURE/CLEARING DIAGNOSTIC TROUBLE CODES under SELF-DIAGNOSTIC SYSTEM. Connect scan tool. Test drive vehicle with no electrical load. Decelerate gradually from 55 MPH for at least 5 seconds. If DTC P0401 does not reset, go to next step. If DTC P0401 resets, clean intake manifold EGR port and EGR passage with carburetor cleaner. Clean passage inside EGR valve with carburetor cleaner, or replace EGR valve as necessary.
- Turn ignition off. Disconnect EGR valve 6-pin connector. Connect battery positive terminal to EGR valve 6-pin connector terminal No. 4 (Blue/Red wire). Start and idle engine. Connect battery negative terminal to EGR valve 6-pin connector terminal No. 6 (Black wire). If engine stalls or runs rough, problem is intermittent. System is okay at this time. If engine does not stall or run rough, clean intake manifold EGR port and EGR passage with carburetor cleaner. Clean passage inside EGR valve with carburetor cleaner, or replace EGR valve as necessary.