What does it mean?
P1404 is a Powertrain (engine, transmission, fuel system) fault code. It indicates: EGR Position Sensor Rationality Closed .
Symptoms
- MIL on
- Unstable idle and stalling when coming to a stop
- Hesitation when pulling away from standstill
- Black smoke or a rich exhaust smell on some engines
- Power loss and higher fuel consumption
- Rough running when the engine is cold
Likely causes
- Carbon build-up holding the EGR valve pintle off its seat
- Position sensor out of calibration or with a worn potentiometer track
- Broken return spring or a sticking valve stem
- High resistance in the sensor signal or ground circuit
- Corroded connector at the EGR valve
- Vacuum line stuck applying vacuum on a vacuum operated valve
- Control module input circuit fault
How to fix it
- Read the EGR position value with the key on and the engine off, it should show fully closed
- Remove the EGR valve and inspect the pintle and seat for carbon deposits
- Clean the valve and the passages, then confirm the pintle returns freely by hand
- Measure the position sensor output through its whole travel while moving the valve
- Check the 5 volt reference and the ground quality at the sensor connector
- Inspect the vacuum lines and the vacuum regulator where fitted
- Replace the EGR valve or its position sensor if the reading does not track smoothly, then relearn the closed position