EGR Valve: Description and Operation

EGR VALVE




The EGR valve (1) is located on the left corner of the front engine bank. The valve uses a stepper motor to drive a worm gear. The worm gear is in mesh with a plunger that controls the exhaust gas passage opening. Plunger movement is monitored by a position sensor. The powertrain control module (PCM) uses a pulse width modulated (PWM) signal to operate the stepper motor. By rotating the stepper motor in different directions, the PCM controls the opening of the exhaust gas passage to the intake manifold.