EGR Valve: Description and Operation

EGR Valve Assembly Sectional View:

DESCRIPTION
The EGR valve regulates the amount of exhaust gas fed to the engine and is part of the Emission System. The Powertrain Control Module (PCM) controls the EGR valve by sending a Pulse Width Modulated (PWM) signal to the bobbin and coil subassembly contained within the EGR valve. The PCM monitors various sensors to control the amount of EGR flow.

The EGR Valve is unique in that the PCM continuously monitors pintle height and continuously corrects it in order to obtain accuracy. When the solenoid is de-energized (PCM breaks the circuit), the pintle is sealed against the orifice, blocking exhaust flow to the cylinder distribution channels.