Circuit Description

Exhaust Gas Recirculation (EGR) system controls level of Oxides of Nitrogen (NOx) emissions by recirculating exhaust gases back into combustion chamber. DTC P0400 will set when:

• Intake pressure changes during steady driving, and throttle position change is less than .244° in 16 firing events.
• Intake pressure changes during deceleration 290 seconds from engine start in fuel shut-off mode.