Circuit Description

EGR valve is equipped with an internal position sensor to determine pintle valve position. PCM controls the EGR 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 monitors the position of the sensor in relation to its duty cycle (commanded on time). DTC will set when actual EGR position from the position sensor is less than or greater than the commanded EGR position based on the duty cycle of the solenoid.

DTC will set if commanded EGR position is less than 80 percent and actual EGR position is greater than or less than 10 or 20 percent of commanded EGR position for 10 seconds. Diagnostic runs continuously once these conditions have been met.