Exhaust Gas Recirculation: Description and Operation

Fig. 24 EGR system diagram.:

Exhaust gas recirculation, Fig. 24 is used to reduce oxides of nitrogen emissions in the vehicle exhaust. EGR uses partial recirculation of the exhaust gases from a port in the cylinder head to a port in the intake manifold.

Fig. 31 Single type EGR control valve.:

The EGR valve, Fig. 31 controls the flow of exhaust gas in response to a vacuum control signal from the EGR control solenoid valve. The EGR solenoid valve is controlled by the ECU in response to variations in engine speed and coolant temperature. EGR flow is suspended during idle and full throttle operation.