P1408 - Exhaust Gas RECIRCULATION (EGR) Flow Out Of Self-Test Range - DTC Chart

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P1408 - EXHAUST GAS RECIRCULATION (EGR) FLOW OUT OF SELF-TEST RANGE - DTC CHART

Description: This test is carried out during the key ON, engine running (KOER) on demand self-test only. The EGR system is commanded on at a fixed engine speed. This DTC sets when the measured EGR flow falls above or below the required calibration.
Possible Causes: For electric EGR (EEGR) system, 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: Use the output state control function of the scan tool and monitor the manifold absolute pressure (MAP) PID and the EEGR PID (EGRMDSD) while commanding the EEGR 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 .