SsangYong Rexton. Service manual - part 431

SSANGYONG Y200

1F2-44 M161 ENGINE CONTROLS

FUEL PRESSURE REGULATOR

YAA1F0F0

Function of the Fuel Pressure Regulator

The fuel pressure regulator maintains the fuel pressure
in the fuel line with the pressure of 3.2 bars to 3.8 bars
according to the intake manifold pressure. This
operating pressure cannot be changed, and the fuel
injection volume will be only determined by the injection
time. Over supplied fuel returns to the fuel tank through
the return line.

There is no negative pressure applied to the spring
chamber (9) during the full load, and it is separated
from the fuel chamber (8) by the diaphragm (5).

When the fuel pressure goes up, the diaphragm forces
the compression spring (6) in the direction of
compression. At this moment, the valve (3) sticks to
the diaphragm by the fuel pressure, and the fuel return
line (2) opens. The fuel over supplied returns to the
fuel tank through the return line.

YAD1F360

2. Fuel return line
3. Valve
5. Diaphragm
6. Compression Spring
8. Fuel Chamber
9. Spring Chamber

1 Vacuum Hose
2 Circlip
3 Fuel Pressure Regulator

4 O-Ring
5 O-Ring

A. Valves Closed
B. Valves Opened

M161 ENGINE CONTROLS 1F2-45

SSANGYONG Y200

YAD1F400

A. Fuel pressure
B. Intake Manifold Negative Pressure

LL. Idling
TL. Partial load
VL. Full load

The pressure difference between the fuel pressure and
the intake manifold is about 3.8 bars during the full
load.

YAD1F370

1. Fuel Pressure Regulator
2. Intake Manifold
3. Fuel Return (to fuel tank)
4. Fuel Supply (from fuel pump)
5. Fuel Pressure (approx. 3.8 bars)
6. Intake Manifold Negative Pressure (0 bar)

The spring chamber (9) is connected to the intake
manifold with the vacuum hose at the intake pipe
connection (7). The negative pressure generated in the
intake manifold activates the diaphragm, and thus the
fuel pressure gets reduced to the rate of the operating
extent of the diaphragm by the intake manifold’s
negative pressure.

YAD1F380

1. Fuel Pressure Regulator
2. Intake Manifold
3. Fuel Return (to fuel tank)
4. Fuel Supply (from fuel pump)
7. Fuel Pressure (approx. 3.2 bars)
8. Intake Manifold Negative Pressure (0.6 bars)

YAD1F390

Consequently, the fuel pressure in the fuel distributor
changes by the intake manifold’s negative pressure,
and  the injector’s fuel pressure gets reduced
independently to the throttle valve’s position. Thus,
the fuel injection  volume can only be determined
according to the injector’s injecting  duration.

The pressure difference between the fuel pressure and

the intake manifold is approx. 3.2 bars during idling.

SSANGYONG Y200

1F2-46 M161 ENGINE CONTROLS

INDUCTION SYSTEM

THROTTLE VALVE ACTUATOR

The throttle actuator is actuated by the Engine Control
Module (ECM) according to the position of the
accelerator pedal position.

It has two potentiometers which signal the position of
the throttle valve to the ECM to enable it to recognize
the various engine load states.

Ignition “Off”

In the de-energized states the throttle valve position
is determined to be spring capsule.

Ignition “On”

When the ignition S/W on the servo motor in the throttle
actuator is operated by the ECM. The throttle valve
adopts a position in line with the coolant temperature.

Closed position

In the closed throttle position, the servo motor controls
engine speed by operating the throttle valve further
(greater mixture) or closing it further (reduced mixture),
depending on coolant temperature and engine load.
When this is done, the throttle valve can be closed
further by the servo motor overcoming the force of the
spring capsule (mechanical end stop). If the actuator
is de-energized, the throttle valve is resting against

YAA1F540

the spring capsule.

Consequently, the throttle valve opening is a constant
10-12 °approximately.

At no load, this produces an engine speed of about
1,800 rpm

Driving

When driving (part/full throttle), the servo motor controls
the throttle valve in line with the various load states
and according to the input signals from the pedal value
sensor according to the input signals from the pedal
value sensor according to the position of the
accelerator pedal.

The function of the EA (electronic accelerator) in the
ECM determines the opening angle of the throttle valve
through the throttle actuator. Further functions are;

•

Idle speed control

•

Cruise control

•

Reducing engine torque for ASR/ABS operation

•

Electronic accelerator emergency running

•

Storing faults

•

Data transfer through CAN

M161 ENGINE CONTROLS 1F2-47

SSANGYONG Y200

YAD1F420

Failure

Code

Description

Trouble Area

Maintenance Hint

Throttle position sensor

1 low voltage

Throttle position sensor

1 high voltage

Throttle position sensor

2 low voltage

Throttle position sensor

2 high voltage

Throttle actuator

learning control failure

Throttle valve return

spring failure

Throttle act uator failure

Different mass air flow

sensor signal with

throttle position sensor

Both throttle position

sensor failure

TPS 1 short circuit to ground

or open

TPS 1 short circuit to power

TPS 2 short circuit to ground

or open

TPS 2 short circuit to power

When actuat or adaption

fluctuation or not meet the

condition

When return spring

defective of actuator

When supply voltage of the

actuat or short circuit to

power

When shut down of out put

driver

When defective of both

potentiometers

•

Monitoring the actual values through
scan tool

•

Inspection the ECM pin 84, 85, 87, 112,
67, 68 about short circuit or open with
bad contact

•

Inspection the throttle valve actuator

•

Inspection the ECM

104

105

108

109

116

119

121

123

125

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