Electronic EGR Transducer (EET) Solenoid Operation

Fig. 27 Electronic EGR Transducer:

OPERATION
The Electric EGR Transducer contains an electrically operated solenoid and a back-pressure controlled vacuum transducer Fig. 27. The PCM operates the solenoid based on inputs from the multi-port fuel injection system. The solenoid/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.

Fig. 28 Electric EGR Transducer:

The solenoid/transducer and EGR valve mount to the rear of the cylinder head Fig. 28.

CIRCUIT OPERATION
Circuit A142 supplies voltage to the EET solenoid. The Powertrain Control Module (PCM) controls the ground path for the solenoid on circuit K35 and connects to cavity 40 of the PCM connector.

Circuit A142 is spliced and connects with the fuel injectors, generator, and the Automatic Shut-Down (ASD) relay. This circuit is HOT when the ASD relay is energized.