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HOMESERVICE MANUALSMERCURY2009MOUNTAINEER 4.6 8, RWDREPAIR AND DIAGNOSIS (SINGLE PAGE)ENGINE PERFORMANCESYSTEMENGINE CONTROLS - POWERTRAIN DTC CHARTS & DESCRIPTIONS (EXCEPT DIESEL & HYBRID)DTC DIAGNOSISDTC P0402: - EXHAUST GAS RECIRCULATION (EGR) FLOW EXCESSIVE DETECTED
2009 Mercury Mountaineer 4.6 8, RWD

DTC P0402: - Exhaust Gas RECIRCULATION (EGR) Flow Excessive Detected

2009 Mercury Mountaineer 4.6 8, RWDSECTION DTC P0402: - Exhaust Gas RECIRCULATION (EGR) Flow Excessive Detected
DTC 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. The test does not pass 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 
Crown Victoria,
E-Series,
Explorer 4.0L,
Explorer Sport
Trac 4.0L,
F-150 4.6L 2V,
F-Super Duty
6.8L,
Grand
Marquis,
Mountaineer
4.0L,
Mustang 4.0L,
Mustang 5.4L,
Town Car		 - GO to Pinpoint Test HH . GO to Pinpoint Test HH .
All others - GO to Pinpoint Test HE . GO to Pinpoint Test HE .
RENDER: 1.0x

NO RELATED

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