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DTC codes / Ford codes / P1405

P1405 · FordDifferential Pressure Feedback Electronic Sensor Circuit Upstream Hose

P1405 on Ford vehicles indicates that the differential pressure feedback electronic (DPFE) sensor has detected a problem with the upstream hose circuit, typically a disconnected, cracked, or blocked hose that prevents the sensor from reading exhaust pressure correctly. The powertrain control module (PCM) sets this code when the sensor signal is out of expected range for the upstream hose, often due to a hose fault rather than the sensor itself.

SystemPowertrain
Code typeFord specific
SeverityMedium
Fix difficultyIntermediate
AreaAuxiliary emission controls

Symptoms you may notice

  • Illumination of the check engine light, often with no other noticeable symptoms.
  • Rough or erratic engine idle, especially when cold.
  • Hesitation or stumble during acceleration.
  • Reduced fuel economy due to incorrect exhaust gas recirculation (EGR) flow.
  • In some cases, a slight surge or bucking at steady speeds.
  • Failed emissions test due to improper EGR operation.

Common causes, most likely first

  1. Disconnected, cracked, or melted upstream hose between the DPFE sensor and the EGR tube.
  2. Blocked or restricted upstream hose due to carbon buildup or debris.
  3. Faulty DPFE sensor (internal failure or contaminated sensing element).
  4. Corroded or damaged electrical connector at the DPFE sensor.
  5. Damaged or clogged EGR tube or passage causing incorrect pressure signal.
  6. Wiring harness damage (open, short, or chafed wires) between the sensor and PCM.

How to diagnose and fix it

  1. Inspect the upstream hose for cracks, disconnection, or blockage; replace if damaged.
  2. Check the DPFE sensor electrical connector for corrosion or loose pins; clean or repair as needed.
  3. Test the DPFE sensor signal with a scan tool or multimeter to verify it responds to pressure changes.
  4. Inspect the EGR tube and passages for carbon buildup; clean or replace if restricted.
  5. Perform a wiggle test on the wiring harness while monitoring sensor data to detect intermittent faults.
  6. Replace the DPFE sensor if the hose and wiring are confirmed good but the signal remains incorrect.
  7. Clear the code and verify repair by completing a drive cycle to ensure the code does not return.

DPFE Hose Faults Mimic Sensor Failure

  • A loose or cracked upstream hose is the most common cause of P1405 on Ford vehicles, yet many technicians replace the DPFE sensor first without checking the hose.
  • The DPFE sensor compares pressure between two hoses; a fault in the upstream hose can cause the sensor to report a signal that looks like a failed sensor, leading to misdiagnosis.
  • Carbon blockage in the EGR tube can create a pressure differential that sets P1405 even when the hose and sensor are functioning correctly.
  • On some Ford models, the DPFE sensor is sensitive to moisture and contamination, so a hose that allows condensation to reach the sensor can cause intermittent P1405 without visible hose damage.
  • P1405 can be set by a poor electrical connection at the sensor, so always inspect the connector pins for corrosion before condemning the sensor.

Can I keep driving with P1405?

You can generally continue driving with P1405, but avoid prolonged idling or heavy acceleration until the fault is repaired, as incorrect EGR flow may affect emissions and fuel economy. If the engine runs rough or stalls, have it checked promptly.

Tools that help

Tools we recommend are in the Auto Veteran shop on Amazon. As an Amazon Associate we earn from qualifying purchases.

Guidance is general and written for Ford vehicles. Exact tests and values vary by model, so confirm the fault before replacing parts.

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