EGR Backpressure Transducer: Description and Operation

Electric EGR Backpressure Transducer-Typical:

ELECTRIC EGR TRANSDUCER-PCM OUTPUT
The transducer mounts to the clean air hose and the EGR valve mount to the rear of the cylinder head.

Electric EGR Backpressure Transducer-Typical:

The Electric EGR Transducer contains an electrically operated solenoid and a back-pressure controlled vacuum transducer. The PCM operates the solenoid based on inputs from the multi- port fuel injection system. The transducer and EGR valve are serviced as an assembly.

When the PCM energizes the solenoid, vacuum does not reach the transducer. Vacuum flows to the transducer when the PCM de-energizes the solenoid.

When exhaust system back-pressure becomes high enough, it fully closes a bleed valve in the vacuum transducer. When the PCM de-energizes the solenoid and back-pressure closes the transducer bleed valve, vacuum flows through the transducer to operate the EGR valve.

De-energizing the solenoid, but not fully closing the transducer bleed hole (because of low back-pressure), varies the strength of the vacuum signal applied to the EGR valve. Varying the strength of the vacuum signal changes the amount of EGR supplied to the engine. This provides the correct amount of exhaust gas recirculation for different operating conditions.