SsangYong Rodius (2013 year). Service manual — part 90

15-31

0000-00

F. Features

As EGR ratio goes up, smoke volume will be

higher. But, this lowers the combustion

chamber temperature and accordingly the

concentration of NOx is decreased. The point

with highest NOx is immediately after TDC.

As EGR temperature goes up, the

concentration of NOx will be higher. Thus, it is

necessary to cool down the exhaust gas.

However, during engine cooled, it may cause

large amount of PM. To prevent this, the

exhaust gas is bypassed the EGR cooler.

15-32

(10) E-VGT control

A. Overview

E-VGT (Electric-Variable Geometry Turbine) turbocharger system in D20DTR engine uses the venturi

effect that controls the flow rate of exhaust gas by adjusting the passage in turbine housing. The newly

adopted DC motor actuator (E-actuator) controls the E-VGT system more precisely and faster. To get

the high operating power from turbine, the ECU reduces the exhaust gas passage In low speed range

and increases it in high speed range.

B. Components

HFM (intake air

temperature)

Front EGT

sensor

E-VGT actuator

Accelerator pedal

module

Crankshaft

position

sensor

Oxygen sensor

T-MAP sensor

Coolant

temperature

sensor

D20DTR ECU

15-33

0000-00

C. Input/Output for E-VGT system

15-34

D. E-VGT system control

Turbocharger system operates the E-VGT actuator according to the signals for engine epm,

accelerator pedal position, atmospheric pressure, T-MAP, coolant temperature and intake air

temperature.

Turbocharger actuator is performed PWM control by ECU.

In general, the boost pressure feedbacks the turbocharger operation and the boost temperature is

used for calculating the precise density.

E-VGT provides higher engine power with faster reaction speed compared to conventional VGT.

Operating wave

Vane

Control

Low

speed

range

In low speed range:
retract the vane to
increase boost
pressure. The vane
has low (-) duty, and
the unison ring
moves to retract the
vane in weak PWM
signal.

High

speed

range

The unison ring
moves to extend the
vane in strong PWM
signal. Maximum
pressure is 3 bar and
the system controls it
according to the input
signals.