Possible causes
– EGR passage clogged
– Faulty EGR Vacuum Modulator Valve
– Faulty EGR Valve
– Faulty EGR solenoid valve
– EGR solenoid valve harness is open or shorted
– EGR solenoid valve circuit poor electrical connection
– Dead (Weak) battery
– Faulty EGR temperature sensor and circuit
– Exhaust gas leaks
– Faulty EGR Vacuum Modulator Valve
– Faulty EGR Valve
– Faulty EGR solenoid valve
– EGR solenoid valve harness is open or shorted
– EGR solenoid valve circuit poor electrical connection
– Dead (Weak) battery
– Faulty EGR temperature sensor and circuit
– Exhaust gas leaks
Tech description
EGR flow malfunction could be caused by a clogged EGR valve or EGR tube. Before replacing any parts try cleaning the EGR valve, tube and passages. If the tubes are clean you may have to replaced the EGR Pressure sensor to fix the problem.
There is a factory service bulletin for the following Ford models:
2000-2002 Ford Taurus
2001-2002 Ford Crown Victoria
2001-2002 Ford Focus
2001-2002 Ford Mustang
2001 Ford Explorer USPS
2001-2002 Ford E Series
2001-2002 Ford Escape
2001-2002 Ford Expedition
2001-2002 Ford Explorer Sport Trac
2001-2002 Ford Explorer Sport
2001-2002 Ford F-150
2001-2002 Ford Ranger
2001-2002 Ford Windstar
2002-2003 Ford Explorer
Ford Factory Service Bulletin OBDII Code P0401 Code
When is the obd code mean?
Low EGR flow control is detected
Symptoms
– Engine Light ON (or Service Engine Soon Warning Light)
– Possible engine hesitation
– Possible engine hesitation
P0401 FORD OBD Code Description