Exhaust Gas Recirculation: Description and Operation

DESCRIPTION

This system recirculates a small amount of exhaust gas into the intake manifold to reduce the combustion temperature, and reduce the NOx emissions. This system consists of the EGR valve, EGR valve position sensor, two solenoid valves, engine control module (ECM) and input devices.

OPERATION

Cold Engine (Coolant temperature less than 55°C (131°F)

EGR operation is stopped to improve driveablity when the engine temperature is cold.





Warm Engine
The engine control module controls the solenoid valves (vacuum side and vent side) to supply EGR gas as described below.