OBD Codes List

Diagnostic reference · P04D1

P04D1

EGR Temperature Sensor C Circuit High

System
Auxiliary emission controls (P code)
Lamp
Check Engine Light
Category
Powertrain - Auxiliary Emissions Controls

What it means

P04D1 means EGR Temperature Sensor C Circuit High.

Where it lives

For P04D1, the sensor sits on the circuit this code reports. The description of P04D1 reports a fault at the sensor.

Check these first

  • EGR temperature sensor C signal pulled high
  • A short to voltage in the sensor C signal wire
  • An open signal return at sensor C driving the reading high
  • Corrosion or water in the sensor C connector
  • A failed thermistor in EGR temperature sensor C

What to do next

  1. Inspect the EGR temperature sensor C connector for corrosion
  2. Test the sensor C signal wire for a short to voltage
  3. Check the sensor C signal return for an open
  4. Read EGR temperature live data on sensor C
  5. Replace EGR temperature sensor C if the signal stays high
  6. Clear the code and retest

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Updated

Generic SAE J2012 definition. Last updated 2026-10-10.