DTC P1404: EGR Position Sensor Not Indicating Closed: Description

EGR valve consists of a pintle valve that moves by the use of an internal solenoid and an internal position sensor used to determine pintle valve position. PCM controls solenoid by supplying ignition voltage whenever exhaust gas needs to be recirculated into intake manifold. PCM monitors EGR solenoid and position sensor circuits for correct voltage levels at certain times. PCM will also monitor position of sensor in relation to its duty cycle. DTC sets when EGR sensor signal voltage is greater than calibrated voltage value when valve is commanded closed.