P1400: EGR / DPFE Sensor Circuit Low Voltage (manufacturer-specific)
2 vehicles · 2 makes · $50-$2,500 repair
Most Reported On
P1400 is an OBD-II diagnostic trouble code meaning “EGR / DPFE Sensor Circuit Low Voltage (manufacturer-specific).” P1xxx codes are manufacturer-defined, so confirm P1400 against your specific brand before buying parts. On Ford — the best-documented version — it is DPFE (Differential Pressure Feedback EGR) sensor circuit low voltage: the PCM saw an out-of-range low signal from the sensor that measures EGR flow. Volkswagen/Audi use P1400 for an EGR valve circuit electrical fault, GM uses it for the cold start emission reduction control system, and Subaru for a fuel tank pressure control solenoid valve circuit fault. In each case it is an emissions fault: the check engine light comes on, the vehicle will fail an emissions test, and you may notice rough idle, pinging, or slightly reduced fuel economy. This code is most commonly reported on 1997-2004 Ford F-150 (XL, XLT, Lariat, FX4, King Ranch), and 2014-2018 Porsche Macan (Macan S Diesel), with repair costs ranging from $50 to $2,500.
Common Causes
Typical Repair Cost
Based on 2 documented vehicle-specific issues. Actual cost depends on root cause and vehicle.
Diagnostic Tools
P1400 does not use the standard P/B/C/U prefix. It may be a manufacturer-specific code, so verify that a scanner supports your exact year, model and module before buying.
FAQ
What does P1400 mean?
P1400 stands for "EGR / DPFE Sensor Circuit Low Voltage (manufacturer-specific)." P1xxx codes are manufacturer-defined, so confirm P1400 against your specific brand before buying parts. On Ford — the best-documented version — it is DPFE (Differential Pressure Feedback EGR) sensor circuit low voltage: the PCM saw an out-of-range low signal from the sensor that measures EGR flow. Volkswagen/Audi use P1400 for an EGR valve circuit electrical fault, GM uses it for the cold start emission reduction control system, and Subaru for a fuel tank pressure control solenoid valve circuit fault. In each case it is an emissions fault: the check engine light comes on, the vehicle will fail an emissions test, and you may notice rough idle, pinging, or slightly reduced fuel economy.
What are the most common causes of P1400?
The most common causes of P1400 are: Failed DPFE / EGR pressure feedback sensor (Ford), Cracked, collapsed, melted, or disconnected rubber hoses between the EGR tube and the DPFE sensor, Clogged EGR passages or a carbon-fouled EGR valve, Open, shorted, or corroded wiring/connector in the sensor or EGR solenoid circuit (VW/Audi: EGR valve circuit electrical fault), Failed EGR vacuum regulator solenoid, Failed PCM/ECU driver circuit (rare — verify everything else first). The specific cause varies by vehicle.
How much does it cost to fix P1400?
Repair costs for P1400 range from $50 to $2,500, depending on the vehicle and root cause.
Which vehicles are affected by P1400?
Au7o has documented P1400 across 2 vehicle models from 2 manufacturers: Ford, Porsche.
Content compiled with AI assistance using NHTSA complaints, TSBs, and owner reports. May contain errors. Always verify with your vehicle's service manual.