EGR Valve Position Sensor Circuit Malfunction (Nissan) / DPFE Sensor Circuit (Ford)
What does P1400 mean?
The P1400 code means the vehicle's onboard diagnostic system has detected: EGR Valve Position Sensor Circuit Malfunction (Nissan) / DPFE Sensor Circuit (Ford). This is a moderate severity code.
Common Symptoms
- Check Engine Light on
- Rough idle
- Engine hesitation or stumble
- Failed emissions test
- Slight increase in NOx emissions
Probable Causes (Ranked by Likelihood)
- Failed EGR valve position sensor or DPFE sensor Very High
- Clogged EGR passages restricting flow High
- Damaged wiring to EGR sensor Moderate
- EGR valve stuck open or closed Moderate
- Clogged EGR hoses or tubes Low
Step-by-Step Diagnostic Procedure
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Test the EGR valve position sensor or DPFE sensor voltage output
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Clean the EGR valve and passages of carbon buildup
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Inspect the wiring and connector at the EGR sensor
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Check the EGR valve for proper opening and closing
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On Ford vehicles, inspect the DPFE sensor hoses for cracks or clogging
Frequently Asked Questions
Can I drive with code P1400?
You can drive short distances. The EGR system primarily affects emissions, so drivability may not be greatly affected. However, you will likely fail an emissions test.
What causes P1400?
A failed EGR position sensor (Nissan) or DPFE sensor (Ford) is the most common cause. Carbon buildup in the EGR passages can also affect sensor readings.
What is the DPFE sensor on Ford?
The Differential Pressure Feedback EGR (DPFE) sensor measures the pressure difference across a metering orifice in the EGR system. It tells the PCM how much exhaust gas is flowing through the EGR valve. These sensors commonly fail on Ford vehicles.