Exhaust Gas RECIRCULATION: Operation
The EGR system is controlled by the EGR valve. When the valve is open, exhaust gas enters the manifold passages. When closed, no gas is allowed to enter the intake manifold. Vacuum signals control the opening and closing of the EGR valve.
Some EGR systems use a Backpressure Transducer to aid in controlling exhaust gas recirculation. This unit senses exhaust gas backpressure and modulates the vacuum signal to the EGR valve in response to the amount of backpressure (this tells the transducer engine operation modes).
Light Duty emissions EGR systems use a backpressure transducer to aid in controlling exhaust gas recirculation. This unit senses exhaust gas backpressure and modulates the vacuum signal to the EGR valve in response to the amount of backpressure. Backpressure is used to provide information on engine operation modes. The backpressure transducer is integral with the EGR valve.