P1401moderate severityPowertrain
DPFE Sensor Circuit High Input
on 2018 Lincoln MKX 2.7L V6 EcoBoost · AWD
What this code means
The DPFE sensor circuit is reading above the maximum expected voltage. This indicates the sensor is reporting excessive EGR flow or has an electrical fault causing a high reading.
Symptoms
- Check Engine Light
- Rough idle
- Engine surge
- Poor fuel economy
- Knocking or pinging
- Failed emissions test
Common causes
- Faulty DPFE sensor (corroded internally — most common)
- DPFE sensor hoses reversed
- Clogged EGR metering orifice
- Wiring short to power
- Vacuum leak in EGR system
Diagnostic steps
- Check DPFE sensor voltage (key on engine off, should be ~0.45-0.55V, if >1V sensor is likely bad)
- Verify DPFE hoses are connected correctly (not reversed)
- Inspect EGR metering orifice for blockage
- Check wiring for shorts to power
Repair notes
Replace DPFE sensor — most common cause. Verify hoses are not reversed. Clean EGR passages.
Other Powertrain codes on this vehicle
P0001
Fuel Volume Regulator Control Circuit/Open
P0002
Fuel Volume Regulator Control Circuit Range/Performance
P0003
Fuel Volume Regulator Control Circuit Low
P0004
Fuel Volume Regulator Control Circuit High
P0010
Intake Camshaft Position Actuator Circuit/Open Bank 1
P0011
Intake Camshaft Position Timing Over-Advanced Bank 1
P0012
Intake Camshaft Position Timing Over-Retarded Bank 1
P0013
Exhaust Camshaft Position Actuator Circuit/Open Bank 1
P0014
Exhaust Camshaft Position Timing Over-Advanced Bank 1
P0015
Exhaust Camshaft Position Timing Over-Retarded Bank 1