DTC P0400 - EGR A Flow

P0400 - EGR A FLOW

Description:	The exhaust gas recirculation (EGR) system is monitored once per drive cycle at high and low load conditions. This DTC sets when a concern is detected by PCM calculations indicating the EGR flow is less or greater than expected.
Possible Causes:	EEGR valve stuck open or closed EEGR connector not seated correctly EEGR stepper motor VPWR circuit open EGRMC circuit open EGRMC circuit short to voltage EGRMC circuit short to ground Vacuum signal to manifold absolute pressure (MAP) sensor restricted or leaking Mass airflow (MAF) sensor signal erroneous Carbon build up in the EEGR valve seat area
Diagnostic Aids:	The following sensors input data to the PCM for correct operation of the EEGR system: engine coolant temperature (ECT), crankshaft position (CKP), intake air temperature (IAT), MAF, throttle position (TP), MAP and vehicle speed sensor (VSS). Diagnose any DTC relating to these sensors prior to addressing this DTC.
Application	Key On Engine Off	Key On Engine Running	Continuous Memory
All	GO to PINPOINT TEST KD .