P1400 — DPFE (EGR) Sensor Circuit Low Voltage
CAUTIONIs it safe to drive? Drive gently and get it looked at soon — it can worsen or fail inspection.
What P1400 means
This is a manufacturer-specific code — its meaning depends on the vehicle’s make (see below).
What P1400 means on specific makes
Heads up: P1400 is a manufacturer-specific code, so the same number means different things by make.
Ford / Lincoln CAUTION
The Differential Pressure Feedback EGR (DPFE) sensor circuit reads low. The DPFE is a notorious Ford failure part — corrodes internally and mis-reports EGR flow, which can also throw lean codes (P0171/P0174) or P0401.
- Failed DPFE sensor ($30-80)
- Disconnected/cracked DPFE hoses ($5-30)
- Wiring fault ($20-100)
Check first: Inspect the two rubber DPFE hoses for cracks, then replace the (cheap) DPFE sensor — fixes most of these.
Source: TroubleCodes.net Ford list / aa1car DPFE article
Mitsubishi CAUTION
Fault in the manifold differential pressure sensor circuit (part of EGR/emissions monitoring on Mitsubishi). Affects EGR control and emissions readiness.
- Failed MDP sensor ($60-200)
- EGR-related vacuum/plumbing issue
- Connector/wiring fault
Check first: Check the MDP sensor signal and the EGR vacuum circuit; inspect the connector.
Source: troublecodes.net/mitsu, ricksfreeautorepairadvice.com/mitsubishi-obd2-codes