DPFE Sensor Circuit High Voltage
What it means
This is a Ford, Lincoln and Mercury code; the same number can mean something different on other makes. The signal voltage from the DPFE sensor, which measures the pressure difference in the EGR tube through two hoses, is above the normal limit. It is roughly equivalent to generic P0406, and the most common cause is a failed sensor or a wiring fault.
Models covered: Ford (and Lincoln/Mercury) models with a DPFE-type EGR system, mainly around 1996–2004.
Symptoms3
- Check engine light on.
- Rough idle or weak running if EGR control is affected.
- Light pinging under load if the computer disables EGR.
Possible causes5
- Failed DPFE sensor.
- Signal wire shorted to a voltage source.
- Open sensor ground.
- Corrosion or moisture in the sensor connector.
- Engine computer fault (rare).
How to diagnose5
- Read DPFE signal voltage on a scan tool, key on and engine off, and compare with the manufacturer specification.
- Measure sensor ground and reference voltage at the connector.
- Unplug the sensor and watch the reading change to separate a sensor fault from a wiring fault.
- Check the signal wire for a short to voltage.
- Inspect the connector for corrosion and moisture.
How to fix4
- Clean the connector or repair the shorted wire or open ground.
- Replace the DPFE sensor, with new hoses if they are cracked.
- Clear the code and confirm the sensor reading is normal.
- Road-test and confirm the EGR test passes.
Repair cost
In Saudi riyals; the highlighted part is the expected range for this fault.
The cost is low for a ground or connector repair, and reaches the top of the range for a new sensor and hoses.
Prices are rough estimates for common cars at independent workshops and vary with the car and the source of the part.
Prices last updated: September 2026
Frequently asked questions
What is the difference between P1400 and P1401?
P1400 means the DPFE signal voltage is low and P1401 means it is high; both are mostly electrical and are fixed by checking the sensor and its wiring.
Should I replace the EGR valve for P1401?
Usually not. The code concerns the DPFE sensor and its circuit; the EGR valve is checked if EGR flow codes appear.
This guide is for information only and does not replace an inspection by a qualified technician. If the fault involves brakes, steering, engine temperature, electrics or refrigerant, do not attempt the repair yourself.
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