P0402 - Exhaust Gas RECIRCULATION (EGR) Flow Excessive Detected

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P0402 - EXHAUST GAS RECIRCULATION (EGR) FLOW EXCESSIVE DETECTED

Description: The EGR system is monitored for undesired EGR flow during idle. The EGR monitor looks at the differential pressure feedback EGR (DPFE) signal at idle and compares it to the stored signal measured during ignition ON, engine OFF. This DTC sets when the signal at idle is greater than at ignition ON, engine OFF by a calibrated amount.
Possible Causes: EGR valve stuck open Plugged EGR vacuum regulator solenoid vent Plugged EGR tube Slow responding differential pressure feedback EGR sensor Damaged differential pressure feedback EGR sensor Incorrect vacuum hose connection Plugged vacuum hoses EVR circuit short to ground Damaged EGR vacuum regulator solenoid
Diagnostic Aids: A DPFEGR PID reading that is greater at idle than during KOEO by 0.5 volt or a rough engine idle may indicate a hard fault.
Application	Key On Engine Off	Key On Engine Running	Continuous Memory
All	GO to PINPOINT TEST HH: EXHAUST GAS RECIRCULATION SYSTEM MODULE (ESM) .