SsangYong Stavic / SsangYong Rodius (2005 year). Manual — part 46

1F-25

CHANGED BY

EFFECTIVE DATE

AFFECTED VIN

ENGINE CONTROLS

M162 GSL ENG SM - 2005.7

IGNITION SWITCH

Failur Code

Description

Trouble Area

Maintenance Hint

• Inspection the Engine Control

Module (ECM) pin 2 circuit short
or open with bad contact

• Inspection ECM

Starter signal

recognition failure

When not detection of starter

signal

71

1F-26

CHANGED BY

EFFECTIVE DATE

AFFECTED VIN

ENGINE CONTROLS

M162 GSL ENG SM - 2005.7

The function of the fuel metering system is to deliver the correct
amount of fuel to the engine under all operating conditions.
The fuel is delivered to the engine by the individual fuel injec-
tors mounted into the intake manifold near each cylinder.
The main fuel control sensors are the Mass Air Flow (MAF)
sensor and the oxygen (O2) sensors.
The MAF sensor monitors the mass flow of the air being
drawn into the engine. An electrically heated element is
mounted in the intake air stream, where it is cooled by the
flow of incoming air. Engine Control Module (ECM) modu-
lates the flow of heating current to maintain the temperature
differential between the heated film and the intake air at a
constant level. The amount of heating current required to
maintain the temperature thus provides an index for the mass
air flow. This concept automatically compensates for varia-
tions in air density, as this is one of the factors that deter-
mines the amount of warmth that the surrounding air ab-
sorbs from the heated element. MAF sensor is located be-
tween the air filter and the throttle valve.
Under high fuel demands, the MAF sensor reads a high
mass flow condition, such as wide open throttle. The ECM
uses this information to enrich the mixture, thus increas-
ing the fuel injector on—time, to provide the correct amount
of fuel. When decelerating, the mass flow decreases. This
mass flow change is sensed by the MAF sensor and
read by the ECM, which then decreases the fuel injector
on—time due to the low fuel demand conditions.
The O2 sensors are located in the exhaust pipe before
catalytic converter. The O2 sensors indicate to the ECM
the amount of oxygen in the exhaust gas, and the ECM
changes the air/fuel ratio to the engine by controlling the
fuel injectors. The best air/fuel ratio to minimize exhaust
emissions is 14.7 to 1, which allows the catalytic con-
verter to operate most efficiently. Because of the con-
stant measuring and adjusting of the air/fuel ratio, the
fuel injection system is called a “closed loop” system.
The ECM uses voltage inputs from several sensors to deter-
mine how much fuel to provide to the engine. The fuel is
delivered under one of several conditions, called ‘‘modes”.

Starting Mode

When the ignition is turned ON, the ECM turns the fuel
pump relay on for 1 second. The fuel pump then builds
fuel pressure. The ECM also checks the Engine Coolant
Temperature (ECT) sensor and the Throttle Position (TP)
sensor and determines the proper air/fuel ratio for start-
ing the engine. This ranges from1.5 to 1 at
-36°C (-33°F) coolant temperature to 14.7 to 1 at
94°C (201°F) coolant temperature. The ECM controls the
amount of fuel delivered in the starting mode by changing
how long the fuel injector is turned on and off. This is
done by ‘‘pulsing” the fuel injectors for very short times.

Run Mode

The run mode has two conditions called ‘‘open loop” and
‘‘closed loop”.

Open Loop

When the engine is first started and it is above 690 rpm,
the system goes into “open loop” operation. In “open loop”,
the ECM ignores the signal from the O2S and calculates
the air/fuel ratio based on inputs from the ECT sensor
and the MAF sensor. The ECM stays in “open loop” until
the following conditions are met:

• The O2 has a varying voltage output, showing that it

is hot enough to operate properly.

• The ECT sensor is above a specified temperature (22.

5°C).

• A specific amount of time has elapsed after starting

the engine.

Closed Loop

The specific values for the above conditions vary with dif-
ferent engines and are stored in the Electronically Eras-
able programmable Read-Only Memory (EEPROM).
When these conditions are met, the system goes into
“closed loop” operation. In “closed loop”, the ECM calcu-
lates the air/fuel ratio (fuel injector on-time) based on the
signals from the O2 sensors. This allows the air/fuel ratio
to stay very close to 14.7 to 1.

Acceleration Mode

The ECM responds to rapid changes in throttle position
and airflow and provides extra fuel.

Deceleration Mode

The ECM responds to changes in throttle position and
airflow and reduces the amount of fuel. When decelera-
tion is very fast, the ECM can cut off fuel completely for
short periods of time.

Battery Voltage Correction Mode

When battery voltage is low, the ECM can compensate
for a weak spark delivered by the ignition module by us-
ing the following methods:

• Increasing the fuel injector pulse width.

• Increasing the idle speed rpm.

• Increasing the ignition dwell time.

Fuel Cut-Off Mode

No fuel is delivered by the fuel injectors when the ignition
is off. This prevents dieseling or engine run-on. Also, the
fuel is not delivered if there are no reference pulses re-
ceived from the CKP sensor. This prevents flooding.

FUEL SYSTEM

1F-27

CHANGED BY

EFFECTIVE DATE

AFFECTED VIN

ENGINE CONTROLS

M162 GSL ENG SM - 2005.7

FUEL PUMP

1. Flange and harness assembly

2. Spring

3. Fuel pump

4. Float

5. Thermistor

6. Float arm

7. Thermistor housing

8. Resistor card and wiper

Requirements for Fuel Pump

Item

System pressure

Maximum pressure

Minimum pressure

Nominal voltage

Minimum amount of fuel
supply

Specified Value

3.8 bar

8.5 bar (12 V)

5.0 bar (12 V)

12 V

114 Liter/Hr (12 V, 3.8 bar,

-30 ~ +70 °C)

Item

Minimum delivery at 8v

Operating voltage

Maximum allowable current

Ambient temperature

Maximum amount of fuel
supply

Specified Value

30 Litre/Hr

8 V

7.5 A

-30 ~ +70 °C

165 Liter/Hr (12V, 3.8 bar,

-30 ~ +70 °C)

1F-28

CHANGED BY

EFFECTIVE DATE

AFFECTED VIN

ENGINE CONTROLS

M162 GSL ENG SM - 2005.7

Circuit Description

When the ignition switch is turned ON, the ECM will activate the pump relay and run the in-tank fuel pump. The fuel
pump will operate as long as the engine is cranking or running and the ECMis receiving ignition reference pulses.

If there are no reference pulses, the ECM will shut off the fuel pump within 2 seconds after the ignition switch is turned
ON, engine stopped or engine stalled.

Fuel Pump Relay Inspection

Measure the voltage between the ECM terminal No. 33 and ground.

Ignition Switch: ON

Cranking

0 V (for1 ~ 2 sec.)

0 V

Failur Code

Description

Trouble Area

Maintenance Hint

• Inspection the Engine Control

Module (ECM) pin 33 about short
circuit or open with bad contact

• Inspection the fuel pump relay

• Inspection the ECM

Fuel pump relay

short circuit to battery

When short circuit to power

source

34

Fuel pump relay

short circuit to ground

or open

When short circuit to ground or

open open with bad contact

35