P0405 EGR Sensor A Circuit Low
What does P0405 mean?
P0405 — EGR Sensor A Circuit Low. This is an OBD-II diagnostic trouble code a scanner retrieves when your vehicle's computer detects egr sensor a circuit low. The level of risk depends on how the vehicle is currently running and how long you've been driving with the light on.
Common causes of P0405
- Shorted or open EGR position sensor signal
- Failed EGR valve position sensor
- Corroded connector
- Faulty PCM reference voltage
How to fix P0405
- Read EGR position voltage with the valve closed
- Check the sensor reference, signal, and ground wires
- Measure the position sensor's resistance range
- Inspect the connector for corrosion
- Replace the EGR valve assembly if the sensor is out of range