SSANGYONG MY2002
4G-2 PARKING BRAKE
DESCRIPTION AND OPERATION
BRAKE CALIPER
This braking system uses a BRAKE warning light lo-
cated in the instrument panel cluster.
The following conditions will activate the BRAKE lamp:
•The parking brake is applied when the ignition is
ON. The lamp will turn off when the parking brake
is released.
The fluid level is below the minimum mark in the
master cylinder reservoir. The lamp will turn off when
the fluid level is above the minimum.
As a test of the lamp circuit, the BRAKE lamp will
glow dimly when the ignition is ON, even if the
parking brake is off and fluid level is above the
minimum. The lamp will turn off when the engine is
started. When the brake is firmly applied, the parking
brake should hold the vehicle with ample pedal
travel remaining.
Check for frayed cables, rust, etc. or any condition
that may inhibit present (or future) free movement of
the parking brake lever assembly.
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
5A-4 AUTOMATIC TRANSMISSION
SSANGYONG MY2002
Output circuits which control external devices such
as the Variable Pressure Solenoid (VPS) driver, On/
Off solenoid drivers, a diagnostics output and the
driving mode indicator light.
Processing Logic
Shift schedule and calibration information is stored in
an Erasable Programmable Read Only Memory (EPROM).
Throttle input calibration constants and the diagnostics
information are stored in Electrically Erasable Program-
mable Read Only Memory (EEPROM) that retains the
memory even when power to the TCM is disconnected.
TCM continuously monitors the input values and uses
these, via the shift schedule, to determine the required
gear state. At the same time it monitors, via the solenoid
outputs, the current gear state, whenever the input
conditions change such that the required gear state is
different to the current gear state, the TCM initiates a
gear shift to bring the two states back into line.
Once the TCM has determined the type of gearshift
required the TCM accesses the shift logic, estimates
the engine torque output, adjusts the variable pressure
solenoid ramp pressure then executes the shift.The TCM continuously monitors every input and output
circuit for short or open circuits and operating range.
When a failure or abnormal operation is detected the
TCM records the condition code in the diagnostics
memory and implements a Limp Home Mode (LHM).
The actual limp home mode used depends upon the
failure detected with the object to maintain maximum
drive-ability without damaging the transmission. In
general input failures are handled by providing a default
value. Output failures, which are capable of damaging
the transmission, result in full limp mode giving only
third or fourth gear and reverse. For further details of
limp modes and memory retention refer to the
Diagnostic Trouble Code Diagnosis Section.
The TCM is designed to operate at ambient
temperatures between - 40 and 85 °C (- 40 and 185 °F).
It is also protected against electrical noise and voltage
spikes, however all the usual precautions should be
observed, for example when arc welding or jump
starting.
TCM Inputs
To function correctly, the TCM requires engine speed,
vehicle speed, transmission fluid temperature, throttle
position, gear position and Kickdown Switch inputs to
determine the variable pressure solenoid current ramp
and on/off solenoid states.
KAA5A030
This ensures the correct gear selection and shift feel
for all driving conditions.
The inputs required by the TCM are as follows;
5A-38 AUTOMATIC TRANSMISSION
SSANGYONG MY2002
DIAGNOSIS
BASIC KNOWLEDGE REQUIRED
You must be familliar with some basic electronics to
use this section of the Service Manual. They will help
you to follow diagnostic procedures.
Notice: Lack of the basic knowledge of this transmis-
sion when performing diagnostic procedures could re-
sult in incorrect diagnostic performance or damage to
transmission components. Do not, under any circum-
stances, attempt to diagnose a transmission problem
without this basic knowledge.
Notice: If a wire is probed with a sharp instrument
and not properly sealed afterward, the wire will corrode
and an open circuit will result.
Diagnostic test probes are now available that allow
you to probe individual wires without leaving the wire
open to the environment. These probe devices are
inexpensive and easy to install, and they permanently
seal the wire from corrosion.
Special Tools
You should be able to use a Digital Volt Meter (DVM),
a circuit tester, jumper wires or leads and a line
pressure gauge set. The functional check procedure
is designed to verify the correct operation of electronic
components in the transmission. This will eliminate the
unnecessary removal of transmission components.
FUNCTIONAL CHECK
PROCEDURE
Begin with the Functional Check Procedure which pro-
vides a general outline of how to diagnose automatic
transmission. The following functional check procedure
will indicate the proper path of diagnosing the transmis-
sion by describing the basic checks and then referenc-
ing the locations of the specific checks.
Check the fluid level according to the Fluid Level
Service Procedure.
Check the transmission fluid leak.
Check if the transmission fluid is not burnt by smell.
Notice: The specific fluid used in this transmission
turns brown during normal operation. Brown fluid
does not indicate a transmission fault.
Ensure that the transmission is not in Limp Home
Mode (LHM).
Check the battery terminals and the earth connec-
tions for corrosion or looseness.
Check that the cooler flow is not restricted.
Check all electrical plug connections for tightness.
Use on-board diagnostic tool or a scan tool to see
if any transmission trouble codes have been set.
DIAGNOSTIC INFORMATION AND PROCEDURES
Refer to the appropriate “Diagnostic Trouble Code
(DTC)” information and repair the vehicle as
directed. After repairing the vehicle, perform the
road test and verify that the code has not set again.
Perform the Electrical/Garage Shift Tests.
Perform the Road Test Procedure in this section.
Inspect the oil and check for metal or other contami-
nants in the oil pan.
TRANSMISSION FLUID LEVEL
SERVICE PROCEDURE
This procedure is to be used when checking a concern
with the fluid level in a vehicle. A low fluid level will
result in slipping and loss of drive/ reverse or delay on
engagement of drive/ reverse when the vehicle is cold.
The vehicle is first checked for transmission diagnostic
messages on the scan tool. If the oil level is low, it is
possible to register a vehicle speed signal fault.
The vehicle is to be test driven to determine if there is
an abnormal delay when selecting drive or reverse, or
loss of drive. One symptom of low fluid level is a
momentary loss of drive when driving the vehicle around
a corner. Also when the transmission fluid level is low,
a loss of drive may occur when the transmission fluid
temperature is low.
If there is no loss of drive when the vehicle is driven
warm and a vehicle speed signal fault is registered,
then fluid should be added to the transmission.
When adding or changing transmission fluid use only
Castrol TQ 95 automatic transmission fluid. The use of
incorrect fluid will cause the performance and durability
of the transmission to be severely degraded.
Fluid Level Diagnosis procedure
1. If the vehicle is at operating temperature allow the
vehicle to cool down for two hours, but no greater
than four hours. Or if the vehicle is at cool status,
start the engine and allow the engine to idle for
approximately 5 minutes or, if possible, drive the
vehicle for a few kilometers. This will allow the
transmission to be within the correct temperature
range. Transmission fluid level should be checked
at temperature 50 - 60 °C (82 - 140 °F).
Caution: Removal of the fluid filler plug when
the transmission fluid is hot may cause injury if
fluid drains from the filler hole.
2. With the brake pedal pressed, move the gear shift
control lever through the gear ranges, pausing a
few seconds in each range. Return the gear shift
control lever to P (Park). Turn the engine OFF.
3. Park the vehicle on a hoist, inspection pit or similar
raised level surface. The vehicle must be control
level to obtain a correct fluid level measurement.
5A-52 AUTOMATIC TRANSMISSION
SSANGYONG MY2002
Circuit Description
The Transmission Control Module (TCM) Diagnistic
System Check is the starting point for any driveability
complaint diagnosis. Before using this procedure,
perform a careful visual/physical check of the
Transmission Control Module (TCM) and the
transmission grounds for cleanliness and tightness.
The TCM Diagnostic System Check is an organized
approach to identifying a problem created by an
electronic transmission control system malfunction.
TCM DIAGNOSTIC SYSTEM CHECK
Diagnostic Aids
An intermittent fault may be caused by a poor connec-
tion, rubbed-through wire insulation or a wire broken
inside the insulation. Check for poor connections or a
damaged harness. Inspect the TCM harness and con-
nections for improper mating, broken locks, improperly
formed or damaged terminals, poor terminal-to-wire
connection, and damaged harness.
TCM Diagnostic System Check
1
StepAction Value(s) Yes No
21 Turn the ignition OFF.
2. Install the scan tool.
3. Turn the ignition ON, with the engine OFF.
4. Attempt to display the Transmission Control
Module (TCM) Data List with the scan tool.
Does the scan tool display the TCM data?
Select the Trouble Code with the scan tool.
Are any Diagnostic Trouble Codes (DTCs) stored?
- Go to Step 2 Go to Step 3
Go to
applicable
DTC table -System OK,
Check
Complete
KAA5A5KA
5A-66 AUTOMATIC TRANSMISSION
SSANGYONG MY2002
Circuit Description
The driving mode selector switch is located on the
center console and allows the driver to select the
driving mode.
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.
The DTC P0790 sets when an intermittent connection
in the mode selector switch (mode switch) circuit has
been detected. The mode switch input is rapidly
changing states. The switching frequency is greater
than 8.3 Hz.
Conditions for Setting the DTC
The mode switching frequency is greater than 8.3
Hz.
The above condition must be continuously present
for 4 state changes.
Action Taken When the DTC Sets
All shifts will occur as if the mode is set to NORMAL.
The mode indicator will always be OFF indicating
that NORMAL mode is selected.
The mode indicator will not respond to the changes
in switch setting.
DIAGNOSTIC TROUBLE CODE (DTC) P0790
NORMAL/PERFORMANCE SWITCH CIRCUIT MALFUNCTION
Conditions for Clearing the DTC
The DTC will clear after 3 seconds without the fault.
A history DTC will clear after 40 TCM power-up
cycles with a warm transmission (>50 °C) and
without a fault.
History DTCs can be cleared by using a scan tool.
Diagnostic Aids
This fault is caused by too many changes in the
mode input signal over a period of time.
Typical causes would be an intermittent connection
in the switch or wiring or an intermittent short to
ground in the wiring.
Test Description
The number(s) below refer to the step number(s) on
the Diagnostic Table.
3. Check mode switch signal circuit for an
intermittent open / short
5. Check mode switch ground circuit for an
intermittent open / short
8. Check mode switch feed circuit for an intermittent
open / short
KAA5A5NA
AUTOMATIC TRANSMISSION 5A-75
SSANGYONG MY2002
DTC P1708 TCM Supply Voltage Low
1Perform a Transmission Control Module (TCM) Diag-
nostic System Check.
Is the check performed?
1. Install the scan tool.
2. Turn the ignition ON, with the engine OFF.
3. Record and then clear DTCs.
4. Operate the vehicle within the conditions for
setting this DTC as specified in the text.
Does the scan tool display P1708?
1. Isolate the driven wheels from the ground and
apply the hand brake.
2. Start the engine and allow it to idle.
3. Move the gear lever to Drive.
4. Select the Ignition Voltage on the scan tool Data
List.
Is the Ignition Voltage less than the specified value?
While running the engine at the specified value, mea-
sure the battery voltage at the battery using a DVM.
Is the battery voltage greater than the specified value?
Check the fuse F23 for a malfunction and replace as
necessary?
Is a repair necessary?
1. Turn the ignition OFF.
2. Disconnect the TCM connector B.
3. Start the engine and raise the engine speed to
specified value.
4. While running the engine at the specified value,
measure the ignition voltage at the ignition feed
circuit terminal B30 using a DVM.
Is the ignition voltage greater than the specified value?
Check for a malfunctioning connection at the TCM
harness terminals and repair as necessary.
Is a repair necessary?
Repair the poor connection (high resistance) at the
ignition feed circuit.
Is the action complete?
1. Turn the ignition OFF.
2. Replace the TCM.
Is the action complete?
1. Using the scan tool, clear the DTCs.
2. Road test the vehicle within the conditions for
setting this DTC as specified in the text.
Does the scan tool indicate that this diagnostic has
run and passed?
Check if any DTCs are set.
Are there any DTCs displayed or previously recorded
at Step 2 that have not been diagnosed?
StepAction Value(s) Yes No
2
3
5
- Go to Step 10 Go to Step 9 6 4
- Go to Step 10 - 7
- Go to Step 10 - 8
- Go to Step 11 Go to Step 2 9
10
- Go to Step 2Go to “TCM
Diagnostic
System Check”
10 V Go to Step 4 Go to Step 10
- Go to Step 3 Go to
“Diagnostic
Aids”
11
-Go to
applicable
DTC tableSystem OK,
Check
Complete
- Go to Step 10 Go to Step 6
Idle in Drive
10 V Go to Step 7 Go to Step 8
Idle in Drive
12 V Go to Step 5 Go to Section
1E, Engine
Electrical
AUTOMATIC TRANSMISSION 5A-77
SSANGYONG MY2002
DTC P1709 TCM Supply Voltage High
1Perform a Transmission Control Module (TCM) Diag-
nostic System Check.
Is the check performed?
1. Install the scan tool.
2. Turn the ignition ON, with the engine OFF.
3. Record and then clear DTCs.
4. Operate the vehicle within the conditions for
setting this DTC as specified in the text.
Does the scan tool display P1709?
1. Start the engine and raise the engine speed to the
specified value.
2. Select the Ignition Voltage on the scan tool Data
List.
Is the Ignition Voltage greater than the specified value?
While running the engine at the specified value, mea-
sure the battery voltage at the battery using a DVM.
Is the battery voltage less than the specified value?
1. Turn the ignition OFF.
2. Disconnect the TCM connector B.
3. Start the engine and raise the engine speed to the
specified vale.
4. While running the engine at the specified value,
measure the ignition voltage at the ignition feed
circuit terminal B30 with respect to the ground
terminal B14.
Is the ignition voltage greater than the specified value?
Check the wiring harness from the fuse F23 to TCM
terminal B30 and from the ground G301 to TCM
terminal B14 for damage.
1. Turn the ignition OFF.
2. Replace the TCM.
Is the action complete?
1. Using the scan tool, clear the DTCs.
2. Road test the vehicle within the conditions for
setting this DTC as specified in the text.
Does the scan tool indicate that this diagnostic has
run and passed?
Check if any DTCs are set.
Are there any DTCs displayed or previously recorded
at Step 2 that have not been diagnosed?
StepAction Value(s) Yes No
2
3
5
6 4
- Go to Step 8 -
7
- Go to Step 8 -
8
- Go to Step 9 Go to Step 2
9
- Go to Step 2Go to “TCM
Diagnostic
System Check”
- Go to Step 3 Go to
“Diagnostic
Aids”
1500 rpm
16.5 V
Go to Step 6 Go to Step 7
1500 rpm
16.5 V Go to Step 4 Go to Step 8
2000 rpm
16.5 V Go to Step 5 Go to Section
1E, Engine
Electrical
-Go to
applicable
DTC tableSystem OK,
Check
Complete