Dodge RAM TRUCK 1500 1995 Service Manual page 1709

B R
EMISSION CONTROL SYSTEMS 25-11
ELECTRICAL SOLENOID
PORTION OF CONTROL VALVE
PORTION (#8 CYLINDER)
OF VALVE v
CONTROL J9525-5
Fig. 16 EGR System Component Location—3.9U
5.2U5.9L Engines
Fig. 17 EGR System Component Location—8.0L
Engine
This may result in; poor engine performance, rough
idle speed and reduced driveability during certain op­
erating conditions.
The EGR valve control also contains an internal
pressure-type transducer (Fig. 18). This transducer
portion of the valve control is operated by exhaust
back-pressure from the EGR valve. Exhaust is deliv­
ered to the EGR valve through the metal EGR tube
(Figs. 19 or 20). This connects it to the rear of the
right exhaust manifold. A rubber hose connects the
back-pressure fitting on the EGR valve to the back­
pressure fitting on the valve control (Fig. 18).
When the ground signal is removed from the elec­
tric portion of the valve control (solenoid is not ener­
gized), and exhaust gas back-pressure entering the
EGR VALVE VACUUM INLET
CONTROL FITTING FROM
ASSEMBLY ENGINE
EGR VALVE
BACK-PRESSURE
FITTING J9525-8
Fig. 18 EGR Valve and EGR Valve Control—Typical
Fig. 19 EGR Tube-3.9U5.2U5.9L Engines
EGR valve inlet is high enough, back-pressure is sup­
plied to the valve control. It then holds the bleed
valve in the transducer closed. This allows engine
vacuum to flow through the EGR valve control to ac­
tivate and operate the EGR valve for exhaust gas re­
circulation. If back-pressure is not strong enough to
close the bleed valve in the transducer, the valve con­
trol will bleed off engine vacuum preventing EGR
valve operation.