Circuit Description
WARNING: This page is about a different car, the 2002 Oldsmobile Intrigue and 2002 Oldsmobile Aurora. However, it is still accessible from the selected car via links, so may be relevant.
The Powertrain Control Module (PCM) monitors Exhaust Gas Recirculation (EGR) valve pintle position input to ensure valve responds properly to PCM commands. When ignition is turned on, the PCM learns the EGR learned minimum position. PCM compares this position to EGR position sensor when EGR valve is commanded closed. If EGR position sensor indicates EGR valve is still open when PCM is commanding EGR valve closed, DTC P1404 will set.