2500 4x2 Pickup V8-5.9L VIN Z (1994)
EGR Backpressure Transducer: Description and Operation
Electronic EGR Transducer (EET) Operation
With California Emissions
EGR Transducer
Electric EGR Transducer (EET)
PURPOSE
The Electric Exhaust Gas Recirculation Transducer combines the functions of the Back Pressure Transducer and the Electric Vacuum Solenoid
into one devise.
TRANSDUCER OPERATION
The backpressure transducer measures the amount of exhaust gas backpressure on the exhaust side of the EGR valve and it varies the amount of
vacuum supplied to the EGR valve. The transducer uses this backpressure signal to supply the correct amount of vacuum to the EGR valve
depending on engine load conditions. Vacuum is supplied to the backpressure transducer from a port on the EVAP Purge Solenoid.
SOLENOID OPERATION
The Electric Vacuum Solenoid is controlled by the Powertrain Control Module (PCM). The PCM monitors engine coolant temperature and other
operating conditions to determine when to energize the solenoid. When the PCM supplies a ground to the solenoid (energizing), vacuum is cut off
from the EGR transducer. When the PCM removes the ground from the solenoid (de-energizing), vacuum is allowed to flow through the solenoid
and out to the EGR transducer.
ON-BOARD DIAGNOSTICS OPERATION
California vehicles are supplied with an on-board diagnostic system for the EGR system. This system has a solenoid that is placed in the vacuum
signal line to the EGR valve. The EGR solenoid is used to disable the EGR system so that the PCM can perform its diagnostic check. This
diagnostic check is activated only during select engine/driving conditions, and checks the entire EGR system for failures. The PCM monitors the
EGR system and if the system check shows a failure, the Malfunction Indicator Lamp in the instrument panel will illuminate indicating that
immediate service is required.