EGR BACKPRESSURE Variable Transducer

A vacuum bleed hole, located inside the transducer, vents EGR vacuum to the atmosphere until sufficient exhaust backpressure is applied, closing the bleed hole. When this happens, vacuum is then routed to the EGR and normal operation begins.

The EGR backpressure variable transducer modulates EGR vacuum so amount of gas flow is in proportion to throttle opening. It does this by sensing exhaust backpressure and bleeding off some of the vacuum when backpressure is low. Since exhaust pressure depends on engine load, it is equivalent to throttle opening signal. The EGR backpressure variable transducer is mounted just above the EGR valve.