Symptoms of P0409 OBD II Trouble Code
- The service engine soon light will illuminate and the OBD code P0409 will be set. Additionally, a second code relating to the EGR sensor failure may be set. Code P0405 relates to a low sensor voltage and P0406 relates to a high voltage situation
- If the EGR pintle is stuck partly open, the vehicle will not idle well or stalls
- Ping from detonation may be heard when under a load or at high RPM
- No symptoms at all
Common Causes of P0409 OBD II Trouble Code
- Defective EGR sensor
- Defect in the wiring harness to the sensor
- EGR pintle stuck in the closed position and a build up of carbon is preventing it from opening
- Lack of vacuum to the EGR solenoid
- Defective EGR solenoid
- Defective EGR position sensor
- Defective differential pressure feedback EGR sensor.