DTC P0403: Exhaust Gas RECIRCULATION Control Circuit Malfunction: Condition

WARNING: This page is about a different car, the 2002 Suzuki Grand Vitara. However, it is still accessible from the selected car via links, so may be relevant.

DTC P0403 is set when one or more EGR valve output voltages are low. Possible causes are:

EGR valve circuit open.
EGR valve malfunction.
ECM (PCM) malfunction.