DPFE Sensor Circuit High Input
2018-2018 Lincoln MKX 2.7L V6 EcoBoost
The 2018 Lincoln MKX is equipped with a 2.7L V6 turbocharged gasoline engine. Below you'll find detailed p1401 diagnostic code information including labor time estimates, cost ranges, and technician notes specific to this engine configuration.
Description
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.
Related Codes
Other Powertrain Codes
- P0001Fuel Volume Regulator Control Circuit/Open
- P0002Fuel Volume Regulator Control Circuit Range/Performance
- P0003Fuel Volume Regulator Control Circuit Low
- P0004Fuel Volume Regulator Control Circuit High
- P0010Intake Camshaft Position Actuator Circuit/Open Bank 1
- P0011Intake Camshaft Position Timing Over-Advanced Bank 1
- P0012Intake Camshaft Position Timing Over-Retarded Bank 1
- P0013Exhaust Camshaft Position Actuator Circuit/Open Bank 1
- P0014Exhaust Camshaft Position Timing Over-Advanced Bank 1
- P0015Exhaust Camshaft Position Timing Over-Retarded Bank 1
P1401 on Other Vehicles
Lincoln Aviator
2003-2003 4.6L V8 DOHC
Lincoln Aviator
2004-2004 4.6L V8 DOHC
Lincoln Aviator
2005-2005 4.6L V8 DOHC
Lincoln Aviator
2020-2020 3.0L Twin-Turbo V6
Lincoln Aviator
2020-2020 3.0L V6 Twin Turbo
Lincoln Aviator
2020-2020 3.0L V6 Twin Turbo Hybrid
Lincoln Aviator
2021-2021 3.0L Twin-Turbo V6
Lincoln Aviator
2021-2021 3.0L V6 Twin Turbo
Common Questions
What does code P1401 mean on a 2018-2018 Lincoln MKX?
P1401 stands for "DPFE Sensor Circuit High Input". 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.
What are the symptoms of P1401 on a Lincoln MKX?
Common symptoms of P1401 include: Check Engine Light, Rough idle, Engine surge, Poor fuel economy, Knocking or pinging, Failed emissions test.
What causes P1401 on a 2018-2018 Lincoln MKX?
Common causes of P1401 include: Faulty DPFE sensor (corroded internally — most common), DPFE sensor hoses reversed, Clogged EGR metering orifice, Wiring short to power, Vacuum leak in EGR system.
Last updated: March 2026