Any DTC relating to these sensors must be resolved prior to addressing P0400 code. P0401 Error Description EGR Flow Insufficient Detected The EGR system is monitored during steady state driving conditions while the EGR is commanded on. The test fails when the signal from the DPF EGR sensor ...
A DPFEGR PID reading that is greater at idle than during key ON and engine OFF by 0.5 volt or a rough engine idle, may indicate a hard fault. P0403 EEGR Electric Motor Windings Or Circuits To The PCM Shorted Or Open The EEGR system is continously monitored to check the 4 EEGR moto...