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P1400

DPFE Sensor Circuit Low Input

1990-1997 Ford Probe 2.0L I4

Moderate SeverityPowertrain

Description

The Differential Pressure Feedback EGR (DPFE) sensor circuit is reading below the minimum expected voltage. The DPFE sensor measures exhaust gas flow through the EGR valve by detecting pressure difference across an orifice in the EGR tube.

Symptoms

  • Check Engine Light
  • Rough idle
  • Stalling
  • Poor fuel economy
  • Failed emissions test

Common Causes

  • Faulty DPFE sensor (most common)
  • Clogged DPFE sensor hoses
  • Wiring short to ground
  • Corroded DPFE sensor from moisture
  • EGR passage blockage

Diagnostic Steps

  1. Check DPFE sensor voltage with key on engine off (should be 0.45-0.55V)
  2. Inspect DPFE sensor hoses for cracks or blockage
  3. Test DPFE sensor wiring for shorts
  4. Check for carbon buildup in EGR passages

Repair Notes

Replace DPFE sensor (most common fix β€” they fail from moisture corrosion). Inspect and clean EGR passages.

Related Codes

P0401EGR Flow Insufficient DetectedP1401DPFE Sensor Circuit High InputP1401EGR Temperature SensorP1401DPFE Sensor Circuit High InputP1401DPFE Sensor Circuit High InputP1401Sub-Throttle Position Sensor Range/PerformanceP1401DPFE Sensor Circuit High InputP1401Sub-Throttle Position Sensor Range/PerformanceP1401Sub-Throttle Position Sensor Range/PerformanceP1401EGR Temperature SensorP1405DPFE Sensor Upstream Hose Off or PluggedP1405DPFE Sensor Upstream Hose Off or PluggedP1405Turbo Pressure Sensor CircuitP1405Turbo Pressure Sensor CircuitP1405DPFE Sensor Upstream Hose Off or PluggedP1405Turbo Pressure Sensor CircuitP1406EGR Valve Pintle Position CircuitP1406EGR Valve Pintle Position CircuitP1406DPFE Sensor Downstream Hose Off or PluggedP1406DPFE Sensor Downstream Hose Off or PluggedP1406EGR Valve Pintle Position CircuitP1406DPFE Sensor Downstream Hose Off or PluggedP1406EGR Valve Pintle Position CircuitP1406EGR Valve Pintle Position CircuitP1406EGR Valve Pintle Position CircuitP1406EGR Valve Pintle Position CircuitP1406EGR Valve Pintle Position Circuit

Other Powertrain Codes

P1400 on Other Vehicles

Common Questions

What does code P1400 mean on a 1990-1997 Ford Probe?

P1400 stands for "DPFE Sensor Circuit Low Input". The Differential Pressure Feedback EGR (DPFE) sensor circuit is reading below the minimum expected voltage. The DPFE sensor measures exhaust gas flow through the EGR valve by detecting pressure difference across an orifice in the EGR tube.

What are the symptoms of P1400 on a Ford Probe?

Common symptoms of P1400 include: Check Engine Light, Rough idle, Stalling, Poor fuel economy, Failed emissions test.

What causes P1400 on a 1990-1997 Ford Probe?

Common causes of P1400 include: Faulty DPFE sensor (most common), Clogged DPFE sensor hoses, Wiring short to ground, Corroded DPFE sensor from moisture, EGR passage blockage.

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