DTC P1408 - EGR Flow Out Of Self Test Range

DTC DESCRIPTION P1408 - EGR FLOW OUT OF SELF TEST RANGE

Description: This test is carried out during the key ON, engine running (KOER) self-test only. The exhaust gas recirculation (EGR) system is commanded on at a fixed engine speed. This DTC sets when the PCM detects the EGR flow is less than or greater than expected.
Possible Causes: Electric exhaust gas recirculation (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) restricted or leaking Mass airflow (MAF) sensor signal erroneous Carbon build up in the EEGR valve seat area
Diagnostic Aids: Use the scan tool to monitor the MAP PID and the EGRPCT PID while commanding the EGR_STEP PID ON. If EGR is introduced into the engine at idle, the RPM drops or stalls out.
Application	Key On Engine Off	Key On Engine Running	Continuous Memory
All	GO to PINPOINT TEST KD .