1F1 -- 54 M162 ENGINE CONTROLS
D AEW OO M Y_2000
FUEL PRESSURE REGULATOR
YAA1F480
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 operat-
ing 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 compres-
sion . At this moment, the valve (3) sticks to the dia-
phragm by the fuel pressure, and the fuel return line (2)
opens. The fuel over supplied returns to the fuel tank
through the return line.
YAA1F490
2. Fuel return line
3. Valve
5. Diaphragm
6. Compression Spring
8. Fuel Chamber
9. Spring Chamber
A. Valves Closed
B. Valves Opened
1F1 -- 60 M162 ENGINE CONTROLS
D AEW OO M Y_2000
HOT FILM AIR MASS (HFM) SENSOR
YAA1F570
The Hot Film Air Mass (HFM) sensor with recognition of flow direction related to pulsating flow is designed for record-
ing load on Engine Control Module (ECM) by measuring the output voltage proportional to the reference voltage of the
ECM.
Mass Air Flow Sensor
Mass Air Flow (MAF) is a thermal flow meter whose sensor element with its temperature sensors and heating area is
exposed to the MAF to be measured. A heating area located in the center of a thin membrane is controlled to an over --
temperature by a heating resistor and a temperature sensor of this membrane. And the value of over -- temperature
depends on the temperature of the in-- flowing air.
Two temperature sensors on upstream and downstream of the heating area show the same temperature without in-
coming flow. With incoming flow, upstream part is cooled down but downstream temperature retains its temperature
more or less due to the air heated up in the heating area. This temperature difference in quantity and direction depends
on the direction of the incoming flow.
ECM modulates 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 MAF. This concept automatically compensates for variations in air density, as this is one of the factors that
determines the amount of warmth that the surrounding air absorbs from the heated element. MAF sensor is located
between 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 (WOT). The
ECM uses this information to enrich the mixture, thus increasing 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.
To facilitate the installation of the HFM in the intake passage, lubricating agents may be used. However, when lubri-
cants are used care must be taken to ensure that they do not enter the flow passage and cannot be sucked in with the
air flow.
1F2 -- 40 M161 ENGINE CONTROLS
D AEW OO M Y_2000
FUEL SYSTEM
The function of the fuel metering system is to deliver the correct amount of fuel to the engine under all operating condi-
tions. The fuel is delivered to the engine by the individual fuel injectors 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 variations in air density, as this is one of the factors that
determines the amount of warmth that the surrounding air absorbs from the heated element. MAF sensor is located
between 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 increasing 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 converter to
operate most efficiently. Because of the constant 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 determine 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 starting the engine. This ranges from 1.5 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, thesystem goes into “open loop” operation. In “open loop”, the
ECM ignores the signal from the HO2S 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:
DThe O2 has a varying voltage output, showing that it is hot enough to operate properly.
DThe ECT sensor is above a specified temperature (22.5°C).
DA specific amount of time has elapsed after starting the engine.
Closed Loop
The specific values for the above conditions vary with different engines and are stored in the Electronically Erasable
Programmable Read -- Only Memory (EEPROM). When these conditions are met, thesystem goes into “closed loop”
operation. In “closed loop”, the ECM calculates 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 deceleration is
very fast, the ECM can cut off fuel completely for short periods of time.
1F2 -- 54 M161 ENGINE CONTROLS
D AEW OO M Y_2000
FUEL PRESSURE REGULATOR
YA A 1 F0 F0
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 operat-
ing 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 compres-
sion . At this moment, the valve (3) sticks to the dia-
phragm by the fuel pressure, and the fuel return line (2)
opens. The fuel over supplied returns to the fuel tank
through the return line.
YAA1F490
2. Fuel return line
3. Valve
5. Diaphragm
6. Compression Spring
8. Fuel Chamber
9. Spring Chamber
A. Valves Closed
B. Valves Opened
1F2 -- 60 M161 ENGINE CONTROLS
D AEW OO M Y_2000
HOT FILM AIR MASS (HFM) SENSOR
YAA1F570
The Hot Film Air Mass (HFM) sensor with recognition of flow direction related to pulsating flow is designed for record-
ing load on Engine Control Module (ECM) by measuring the output voltage proportional to the reference voltage of the
ECM.
Mass Air Flow Sensor
Mass Air Flow (MAF) is a thermal flow meter whose sensor element with its temperature sensors and heating area is
exposed to the MAF to be measured. A heating area located in the center of a thin membrane is controlled to an over --
temperature by a heating resistor and a temperature sensor of this membrane. And the value of over -- temperature
depends on the temperature of the in-- flowing air.
Two temperature sensors on upstream and downstream of the heating area show the same temperature without in-
coming flow. With incoming flow, upstream part is cooled down but downstream temperature retains its temperature
more or less due to the air heated up in the heating area. This temperature difference in quantity and direction depends
on the direction of the incoming flow.
ECM modulates 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 MAF. This concept automatically compensates for variations in air density, as this is one of the factors that
determines the amount of warmth that the surrounding air absorbs from the heated element. MAF sensor is located
between 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 (WOT). The
ECM uses this information to enrich the mixture, thus increasing 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.
To facilitate the installation of the HFM in the intake passage, lubricating agents may be used. However, when lubri-
cants are used care must be taken to ensure that they do not enter the flow passage and cannot be sucked in with the
air flow.
SSANGYONG MY2002
4D-6 FRONT BRAKES
KAA4D080
FRONT DISC BRAKE ROTOR
Removal and Installation Procedure
1. Raise and suitably support the vehicle.
2. Remove the front wheels. Refer to Section 2E,
Tires and Wheels.
3. Remove the hub bearing assembly. Refer to
Section 2C, Front Suspension.
4. Remove the front disc brake rotor.
5. Installation should follow the removal procedure in
the reverse order.
KAA4D040
REPAIR INSTRUCTIONS
ON-VEHICLE SERVICE
BRAKE PADS
Removal and Installation Procedure
1. Raise and suitably support the vehicle.
2. Remove the front wheels. Refer to Section 2E,
Tires and Wheels.
3. Remove the caliper guide lower bolt.
Important: Caliper assembly removal is not
necessary to service the brake pad.
Installation Notice
Take care not to damage the piston seal when
the retaining frame is pulled down.
Tightening Torque 31 Nm (23 lb-ft)
KAA4D050
4. Remove the brake pads.
Installation Notice:
Measure the minimum brake pad thickness.
Refer to “Lining Inspection” in this section.
Always change the all pads on one wheel at a
time.
5. Installation should follow the removal procedure in
the reverse order.
SSANGYONG MY2002
4F-36 ABS AND TCS
SELF-DIAGNOSTICS
Important: The electronic brake control module (EBCM)
turns the valve relay off when a diagnostic trouble code
(DTC) is set. The scan tool will indicate that the valve
relay is off when it is used to monitor the data list. This
is normal and should not be considered a mal-function.
The EBCM performs system self-diagnostics and can
detect and often isolate system malfunctions. When it
detects a malfunction, the EBCM sets a DTC that repre
sents the malfunction, turns on the ABS and/or the
TCS indicators in most instances, and may disable the
ABS and/or the TCS functions, as necessary, for the
duration of the ignition cycle.
Once each ignition cycle, the EBCM performs an auto-
matic test when the vehicle reaches 2.75 km/h (1.7
mph). In the course of this test, the system cycles
each valve solenoid and the pump motor, along with
the necessary relays, to check component operation.
If the EBCM detects any malfunctions, it will set a
DTC as described above.
DISPLAYING DTCs
Tools Required
Scan Tool
DTCs can be read through the use of the scan tool.
CLEARING DTCs
Tools Required
Scan Tool
The diagnostic trouble codes (DTCs) in the electronic
brake control module (EBCM) memory are erased in
one of two ways:
Use the scan tool “Clear DTCs” selection.
After 249 DTC-free ignition cycles.
These two methods are detailed below. Be sure to verify
the proper system operation and, the absence of DTCs
when the clearing procedure is completed.The EBCM will not permit DTC clearing until all DTCs
have been displayed. Also, DTCs cannot be cleared
by disconnecting the EBCM, disconnecting the battery
cables, or turning the ignition switch to LOCK.
Scan Tool Method
The scan tool can clear ABS/TCS system DTCs using
the mass storage cartridge.
1. Install the scan tool and the mass storage
cartridge.
2. Select “Fault Memory”.
3. Select “Clear Fault Memory”.
Clearing the fault memory cannot reset a valve relay
which was shut down when the fault was recognized.
Changes are possible only after the fault has been elimi-
nated and the next ignition cycle has begun.
Ignition Cycle Default
A DTC is erased from memory after 249 ignition cycles
without any reappearance of that malfunction.
INTERMITTENTS AND POOR
CONNECTIONS
As with most electronic systems, intermittent malfunc
tions may be difficult to diagnose accurately. The follow-
ing is a method to try to isolate an intermittent
malfunction, especially in wheel speed circuitry.
If an ABS malfunction occurs, the ABS indicator will
illuminate during the ignition cycle in which the
malfunction was detected. If it is an intermittent problem
which seems to have corrected itself (ABS indicator
OFF), a history DTC will be stored. Also stored will be
the history data of the DTC at the time the malfunction
occurred. Use the scan tool modular diagnostic system
to read ABS history data.
Most intermittents are caused by faulty electrical con
nections or wiring, although a sticking relay or solenoid
can occasionally be at fault.
AUTOMATIC TRANSMISSION 5A-3
SSANGYONG MY2002
N - Neutral allows the engine to be started and oper-
ated while driving the vehicle. The inhibitor switch
allows the engine to be started. There is no power
transferred through the transmission in Neutral. But
the final drive is not locked by the parking pawl, so
thewheels are free to rotate.
D - Overdrive range is used for all normal driving
conditions. 4th gear (overdrive gear) reduces the
fuel consumption and the engine noise. Engine
braking is applied with reduced throttle.
First to second (1 → 2), first to third (1 → 3), second
to third (2 → 3), second to fourth (2 → 4), third to
fourth (3 → 4), fourth to third (4 → 3), fourth to
second (4 → 2), third to second (3 → 2), third to
first (3 → 1) and second to first (2 → 1) shifts are
all available as a function of vehicle speed, throttle
position and the time change rate of the throttle
position.
Downshifts are available for safe passing by
depress-ing the accelerator. Lockup clutch may be
enabled in 3rd and 4th gears depending on vehicle
type.
3 - Manual 3 provides three gear ratios (first through
third) and prevents the transmission from operating
in 4th gear. 3rd gear is used when driving on long
hill roads or in heavy city traffic. Downshifts are
available by depressing the accelerator.
2 - Manual 2 provides two gear ratios (first and
second). It is used to provide more power when
climbing hills or engine braking when driving down
a steep hill or starting off on slippery roads.
1 - Manual 1 is used to provide the maximum engine
braking when driving down the severe gradients.When NORMAL mode is selected upshifts will occur
to maximize fuel economy. When POWER mode is se-
lected, upshifts will occur to give maximum
performance and the POWER mode indicator light is
switched ON.
When WINTER mode is selected, starting in second
gear is facilitated, the WINTER mode indicator light is
switched ON and the POWER mode indicator light is
switched OFF.
Indicator Light
The indicator light is located on the instrument panel.
Auto shift indicator light comes ON when the ignition
switch ON and shows the gear shift control lever
position.
POWER mode indicator light comes ON when the
POWER mode is selected and when the kickdown
switch is depressed.
WINTER mode indicator light comes ON when the
WINTER mode is selected.
CONTROL SYSTEMS
BTRA M74 4WD automatic transmission consists of
two control systems. One is the electronic control
system that monitors vehicle parameters and adjusts
the transmission performance. Another is the hydraulic
control system that implements the commands of the
electronic control system commands.
ELECTRONIC CONTROL SYSTEM
The electronic control system comprises of sensors, a
TCM and seven solenoids. The TCM reads the inputs
and activates the outputs according to values stored
in Read Only Memory (ROM).
The TCM controls the hydraulic control system. This
control is via the hydraulic valve body, which contains
seven electromagnetic solenoids. Six of the seven
solenoids are used to control the line pressure, operate
the shift valves and the torque converter lock-up clutch,
and to turn ON and OFF the two regulator valves that
control the shift feel.
The seventh solenoid is the proportional or Variable
Pressure Solenoid (VPS) which works with the two regu-
lator valves to control shift feel.
Transmission Control Module (TCM)
The TCM is an in-vehicle micro-processor based trans-
mission management system. It is mounted under the
driver’s side front seat in the vehicle cabin.
The TCM contains:
Processing logic circuits which include a central mi-
croprocessor controller and a back-up memory
system.
Input circuits.
Driving Mode Selector
The driving mode selector consists of a driving mode
selector switch and indicator light. The driving mode
selector is located on the center console and allows
the driver to select the driving mode.
The driving modes available to be selected vary with
vehicle types. Typically the driver should have the
option to select among NORMAL, POWER and
WINTER modes.
KAA5A020