107949
Figure 320
540730
Heat exchanger
108399
107948
1. Throttle valve - 2. Electric actuator - 3. Throttle position
signal - 4. Ground - 5. Voltage - 6. PWM signal
The throttle valve (N.O.) assembly, fitted on the inlet mani-
fold, controls the amount of air from the intercooler, to be
mixed with the exhaust gas made to circulate by the E.G.R.
valve, according to a programmed percentage.
The circulated exhaust gas will be mixed with the air from the
intercooler within a duct obtained in the cylinder head.
The throttle valve is operated by an electric actuator control-
led by a PWM signal from EDC control unit 16.
In the event that the throttle valve gets stuck, the control unit
will reduce the engine performance to avoid possible damage
to the engine itself.
When the engine is switched off, the throttle valve will closet
o reduce the engine noise during this phase.
Figure 321
The heat exchanger fitted between the turboblower and the
throttle valve assembly is used to lower the exhaust gas
temperature in order to accordingly reduce the volume of
the same.
It consists of a body that incorporates a number of
corrugated pipes. The circulated exhaust gas flowing through
the pipes are cooled by the engine coolant flowing inside the
body.
Figure 322
EXHAUST GAS COOLING SCHEME
A. Intake exhaust gasses - B. Cooled exhaust gasses - C. Coolant to heater -
D. E.G.R. valve exhaust gasses - E. Coolant incoming from cylinder head - F. Air from intercooler
Air from intercooler
Cooled exhaust gasses
Engine coolant
Hot exhaust gasses
Circulated exhaust gas/air mixture
288
F1C ENGINE
D
AILY
E
URO
4
Throttle valve assembly