DTC Will Set When The Following Conditions Are Present:
WARNING: This page is about a different car, the 1997 GMC Savana, 1997 Chevrolet Chevy Van, and 1997 Chevrolet Chevy Express. However, it is still accessible from the selected car via links, so may be relevant.
- EGR flow test will fail and DTC P0401 set if VCM does not detect a sufficient rise in manifold absolute pressure during listed conditions.