Exhaust Gas Recirculation: Description and Operation

EGR Control System:

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, Powertrain Control Module (PCM) and input devices.

EGR Control System Operation:

Operation
Cold Engine (Coolant Temperature Below 55°C (131°F)
EGR operation is stopped to improve driveablity when the engine temperature is cold.

Warm Engine
The PCM controls the solenoid valves (vacuum side and vent side) to supply EGR gases as described below.