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SsangYong Rexton. Manual - part 51

DI04-17

CHANGED BY

EFFECTIVE DATE

AFFECTED VIN

EXHAUST SYSTEM

DI ENG SM - 2004.4

Diagnosis and Measure

Poor Engine Power or Smoke Discharge

Air Cleaner Contamination

and Clogging of Oil Pass

Type Air Cleaner

Slack between Compres-

sor Entrance and Exhaust

Manifold Connection

Leaks at Intake Manifold

YES

Replace Air Cleaner

Element or Oil Pass Type

Air Filter

Reconnect Connections

Inspect and Repair

Intake Manifold

Leaks at Exhaust Mani-

fold

Leaks at Turbo Charger

Connecting Flange

Poor Rotation or Interfer-

ence of Turbo Charger

Components

YES

Inspect and Repair Intake

Manifold

Refer to Diagnosis

Table

Clogging Between Air

Cleaner and Compressor

Clogging Between Com-

pressor Exit and Intake

Manifold

Clogging of Engine Muffler

YES

Clean or Replace Affected

Components

Clean or Replace Affected

Components

Clean or Replace

Affected Compo-

nents

Clogging of Engine Intake/

Exhaust Manifold

Weakness of Engine

Function, Intake/Exhaust

Valve Damage, Timing

Defects of Each Valve

YES

Inspect and Repair

Related Components

YES

Inspect and Repair

Related Components

DI04-18

CHANGED BY

EFFECTIVE DATE

AFFECTED VIN

EXHAUST SYSTEM

DI ENG SM - 2004.4

Before Diagnosis

The base of making diagnosis on the EGR related system is the inspection on the connections of the vacuum hoses in
related system as the first priority. When abnormal condition occurs with the EGR system, the basic approach is, as
described in prior sentence, making detail inspections of vacuum circuits of each system before connecting the scan
tool or vacuum tester. It is necessary to manually check on the connections if there are any slacks or loose circuits even
if the visual inspection shows vacuum hose as being connected. If there are not any problems then the next inspection
area is the connections of the system connectors. Most problems with the occurrence of system malfunction are from
conditions of vacuum line and connector connections and the causes from the malfunction of mechanical mechanism is
actually very few.

For example, when there are no problems with basic components, let’s assume that there is a vehicle having vacuum
leak from connection slack in the vacuum line between EGR vacuum modulator and EGR valve. This vehicle, due to the
driving condition or, according to the circumstances, smog or other conditions, could create customer’s complaint and
by connecting the scanning device could display as the malfunction of the EGR valve’s potentiometer.

As previously explained, this car has a separate controller to control the Hoover EGR and, in accordance with various
input element, the controller controls EGR valve by regulating the force of vacuum being applied to the EGR valve through
PWM control. At this time, the controller has to receive feedback whether the EGR valve operates correctly according to
the value sent to the EGR modulator and this role is performed by the EGR potentiometer located at top section of the
EGR valve.

In other word, the controller sent correct output value to the EGR vacuum modulator but, due to the leakage of vacuum,
signal of required value can not be received from the EGR potentiometer causing to display as malfunction of related
parts.

As a reference, the EGR valve of diesel vehicle (DI Engine) controlling from the engine ECU to EGR system has different
shape than the Hoover EGR valve because the EGR valve’s operation signal in the DI engine is performed by the HFM
sensor instead of the EGR potentiometer.

This principle is that when the EGR valve opens up to flow exhaust gas into the intake unit the amount of fresh air,
comparatively, will be reduced. The DI engine ECU receives feedback signal of change in amount of air being passed
through the HFM sensor according to the opening amount of the EGR valve.

Hoover EGR System for IDI Engine

(Including the EGR Valve Potentiometer)

EGR System for DI Engine

Y220_04013

DI04-19

CHANGED BY

EFFECTIVE DATE

AFFECTED VIN

EXHAUST SYSTEM

DI ENG SM - 2004.4

The other big difference between the Hoover EGR and EGR controller for DI engine is that from two vacuum modulator,
one is same as being the modulator for EGR valve whereas the Hoover EGR system’s the other modulator controls
ALDA of injection pump and the DI engine’s the other modulator controls waist gate of the turbo charger.

This difference is in accordance with the difference in fuel injection method where the IDI engine has mechanical
injection system and DI engine is capable of making electronically controlled fuel injection.

In other word, to reduce the amount of the fuel injection in no-load rapid acceleration mode, the IDI engine’s Hoover EGR
utilizes solenoid valve to disconnect the connection circuit between intake manifold and ALDA causing negative pres-
sure to occur in the vacuum modulator to reduce the amount of fuel injection. When DI engine, basing input signal from
the related sensors such as acceleration pedal sensor and engine RPM, recognizes that current mode is the no-load
rapid acceleration mode it reduces the amount of fuel injection by sending short electrical signal to the injector. Therefore,
disregarding the modulator for the EGR valve in DI engine, one must keep in mind that the other modulator is used to
control the booster pressure valve in turbo charger.

DI04-20

CHANGED BY

EFFECTIVE DATE

AFFECTED VIN

EXHAUST SYSTEM

DI ENG SM - 2004.4

When Engine Exhaust Gas shows White Smog or Blue Smog

Poor Connection between

Compressor Outlet and

Intake Manifold

Oil Leak Sign around

Intake Manifold

Clogging of Engine Oil

Element

YES

Reconnection

Inspect PVC Line

Replace Oil Filter

Clogging or Damage

between Air Cleaner and

Turbo

Oil Leakage at Seal

between Turbo Charger

and Compressor

Engine Malfunction (Ring,

Piston, Valve)

YES

Clean or Replace Affected

Components

Repair (overhaul)

Engine

Improper Inspection of Air

Cleaner Contamination

Improper Viscosity of

Engine Oil Being Used

Poor Oil Seal at Turbo

Compressor Side (Oil leak

sign at housing and wheel)

YES

Replace Air Cleaner

Element

Replace with Specified Oil

Refer to Diagnosis

Table

Poor Oil Seal at Turbo Turbine

Side (trace of leakage in

housing and wheel)

Oil Leakage at Engine

Exhaust Manifold (damages

to ring, piston and valve)

YES

Refer to Diagnosis Table

YES

Inspect or repair Manifold

YES

Refer to Diagnosis Table

Excessive Consumption of Engine Oil

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