1997 SSANGYONG KORANDO 4WD

SECTION 5D1
TRANSFER CASE (TOD)
CAUTION: Disconnect the negative battery cable before removing or installing any electrical unit or when a
tool or equipment could easily come in contact with exposed electrical terminals. Disconnecting this cable
will help prevent personal injury and damage to the vehicle. The ignition must also be in LOCK unless
other-wise noted.
TABLE OF CONTENTS
Description and Operation.................................5D1-2
Torque on Demand (TOD) System
Transfer Case.................................................5D1-2
Transfer Case Control Unit (TCCU).....................5D1-2
TCCU Coding....................................................5D1-2
Pin Description..................................................5D1-3
Components of the TOD Transfer Case System ..5D1-4
Definition of Terminology....................................5D1-4
Operation of the TOD Transfer Case System......5D1-4
Component Locator...........................................5D1-7
Torque on Demand (TOD) Type Transfer Case....5D1-7
Transfer Case Disassembled View.....................5D1-8
TOD Control Unit..............................................5D1-10
Diagnosis..........................................................5D1-11
Self-Diagnostic Tests.......................................5D1-11
Diagnostic Trouble Codes (DTCs)....................5D1-12
Clearing Diagnostic Trouble Codes..................5D1-12
4WD Check Indicator Stays on with Ignition
Switch ON....................................................5D1-14
4WD Low Indicator Stays on with Ignition
Switch ON....................................................5D1-16
No 4WD Check or 4WD Low Indicator with
Ignition Switch ON........................................5D1-18
4WD Low Indicator Blink Steadily.....................5D1-20
TCCU Diagnostic System Check......................5D1-21
DTC 1714 Eeprom Checksum Fault..................5D1-22
DTC 1715 Tp Sensor Loss of Signal.................5D1-24
DTC 1716 Tp Sensor Out of Range...................5D1-26
DTC 1721 Electromagnetic Clutch Open / Short
to Battery.....................................................5D1-28
DTC 1722 Electromagnetic Clutch Short to
Ground.........................................................5D1-32
DTC 1731 Front Speed Sensor Voltage Low......5D1-36
DTC 1732 Front Speed Sensor Voltage High.....5D1-38DTC 1733 Rear Speed Sensor Voltage Low......5D1-40
DTC 1734 Rear Speed Sensor Voltage High.....5D1-42
DTC 1735 Speed Sensor Reference Voltage
Low ..............................................................5D1-44
DTC 1736 Speed Sensor Reference Voltage
High.............................................................5D1-46
DTC 1741 Motor Output Open / Shorted
to Battery.....................................................5D1-48
DTC 1742 Motor Output Shorted to Ground......5D1-52
DTC 1743 Shift System Timeout.......................5D1-55
DTC 1750 General Position Encoder Fault
(Invalid Code)...............................................5D1-56
DTC 1751 Position 1 Shorted to Ground............5D1-58
DTC 1752 Position 2 Shorted to Ground............5D1-60
DTC 1753 Position 3 Shorted to Ground............5D1-62
DTC 1754 Position 4 Shorted to Ground............5D1-64
Repair Instructions............................................5D1-66
On-Vehicle Service.............................................5D1-66
Oil Replacement..............................................5D1-66
Transfer Case Control Unit (TCCU)...................5D1-67
Transfer Case..................................................5D1-67
Shift Motor.......................................................5D1-69
Front and Rear Propeller Shaft Speed Sensor ...5D1-70
Unit Repair........................................................5D1-71
Transfer Case Overhaul...................................5D1-71
Specifications...................................................5D1-79
General Specification.......................................5D1-79
TCCU Electric Characteristics..........................5D1-79
Fastener Tightening Specifications...................5D1-79
Schematic and Routing Diagram....................5D1-80
TOD Transfer Case Control Unit (TCCU)............5D1-80
Special Tools and Equipment..........................5D1-82
Special Tool Table ...........................................5D1-82

TRANSFER CASE 5D1-3
SSANGYONG MY2002
A1
A2
A3
A4
A5
A6
A7
A8
A9
A10
A11
A12
B1
B2
B3
B4
B5
B6
B7
B8
B9
B10
B11
B12
B13
B14
B15
B16
B17
B18Shift motor output (- High to low: Battery voltage/ - Low to high or motor brake : Ground)
Shift motor output (- Low to high: Battery voltage/ - High to Low or motor brake : Ground)
TOD output: Electromagnetic clutch control
B (+) : Fuse F17
Ignition Voltage: Fuse F23
Shift motor output (- High to low: Battery voltage/ - Low to high or motor brake : Ground)
Shift motor output (- Low to high: Battery voltage/ - High to Low or motor brake : Ground)
Reference voltage (5V) supply to Throttle Position (TP) sensor and speed sensor
Ground
Ground
B (+) : Fuse F17
Diagnosis (K-line)
Position encoder ground
Illuminate 4WD CHECK lamp
Not in used
Mode (4H/4L) input
Position encoder 2 input
Front propeller shaft speed sensor input
Not in used
Speed sensor ground. Throttle position (TP) sensor return
Illuminate 4WD LOW indicator
CAN bus high line
CAN bus low line
Neutral position sensor signal input (A/T only)
ABS operation signal (ON/OFF)
Brake switch signal input
Position encoder 1 input
Position encoder 3 input
Rear propeller shaft speed sensor signal input
Position encoder 4 input
PIN DESCRIPTION
Pin No.Description

SSANGYONG MY2002
5D1-4 TRANSFER CASE
COMPONENTS OF THE TOD
TRANSFER CASE SYSTEM
Shift Motor
It locates backside transfer case, which drives rotary
helical cam. When mode select switch changes to 4L,
shift fork is on position for 2.48 : 1 by rotation of helical
cam.
Rear Speed Sensor
A hall effect speed sensor which produces a square
wave. 0 to 5 volts direct current signal in response to
a rotating 30-tooth wheel coupled to the rear propeller
shaft inside the transfer case. Each rotation of the rear
propeller shaft will result in 30 speed sensor pulse.
Front Speed Sensor
A hall effect speed sensor which produces a square
wave. 0 to 5 volts direct current signal in response to
a rotating 30-tooth wheel coupled to the front propeller
shaft inside the transfer case. Each rotation of the front
propeller shaft will result in 30 speed sensor pulse.
Electro-Magnetic Clutch
An electromagnetic clutch used to control the amount
of torque applied to the front propeller shaft.
Position Encoder
A set of 4 gray code switches which provide feedback
to the TCCU indicating the position of the shift motor.
Clutch Pedal Position Switch
A switch on vehicles equipped with a manual transmis-
sion which indicates that the clutch pedal is depressed
Park/Neutral Position Switch
A switch on vehicles equipped with an automatic trans-
mission which indicates that the transmission is in neu-
tral.
4H/4L Switch
A switch selects the desired gear ratio.
DEFINITION OF TERMINOLOGY
Shift Inhibit Speed
The vehicle speed limit, which transfer case shifts, is
disallowed. Vehicle speed is indicated by propeller
shaft speed measurement.
Duty Cycle
Duty cycle is the time the electromagnetic clutch is on
divided by the period in which it is being modulated.
Touch-off
A minimum amount of duty cycle applied to the electro
magnetic clutch.
Front Overrun
A condition where the front propeller shaft is turning at
a rate which is faster than the rear propeller shaft.
Rear Overrun
A condition where the rear propeller shaft is turning at
a rate which is faster than the front propeller shaft.
High Range
The highest (numerically lowest = 1 : 1) gear ratio be-
tween the input and outputs of the transfer case.
Low Range
The lowest (numerically highest = 2.48 : 1) gear ratio
between the input and outputs of the transfer case.
OPERATION OF THE TOD
TRANSFER CASE SYSTEM
Initial Operation of TOD Control Unit
When ignition switch is turned to ON, 4WD LOW and
4WD CHECK lamp illuminates for 0.6 second to check
bulb in instrument panel, then perform diagnosis of
system. Refer to “Self-Diagnosis Test” in this section.
Electric Shift System Operation
The electric shift system is responsible for changing
the transfer case gear ratio by controlling the electric
shift motor. The TCCU monitors the 4H/4L switch, park/
neutral position switch, speed sensors, position
encoder, and ignition switch.
A range change is initiated when:
The 4H/4L switch is changed from 4H to 4L or from
4L to 4H.
The motor position (as indicated by the position
encoder) does not match the 4H/4L switch
immediately after the ignition is turned on.
Shift Criteria
When a range change is initiated a diagnostic test will
be completed on the motor, speed sensors, and
position encoder. If the diagnostic test fails, the shift
will not be attempted. If all components are operating
properly, the TCCU will attempt a range change after
the following shift criteria are met:
The transmission is in neutral for 2 seconds after
the shift is requested.
Both propeller shaft speeds are below 87 rpm (2580
pulses/minute). If the transmission is taken out of
neutral before 2 seconds has passed, or either
propeller shaft speed increases above the limit, the
shift will be suspended and the 4L indicator will
continue to blink until the criteria are met again or
the 4H/4L switch is returned to the original position.
Range Change
When the shift criteria are met, the motor is rotated in
the appropriate direction (as determined by the selector
switch) until one of the following occurs:

TRANSFER CASE 5D1-5
SSANGYONG MY2002
The motor reaches its destination.
The motor is on for 5 seconds without reaching its
destination. The shift has failed and the TCCU will
respond as default mode.
A fault occurs with either the motor or position
encoder. Refer to the diagnosis requirement.
When the motor is energized, the Ignition, 4H/4L
switch, propeller shaft speeds, and transmission
neutral inputs are ignored.
Indicator Function
Once a range change has been initiated the 4WD LOW
indicator will begin to blink at a rate of 0.3 seconds
on, 0.3 seconds off until the shift is completed or
canceled. If a successful shift has been completed,
the 4WD LOW indicator will be illuminated if the motor
is in low range and it will be turned off if the motor is in
high range.
4WD LOW indicator illuminates as below figure.
KAA5D000
TODTM System Operation
The TODTM System is responsible for distributing torque
between the front and rear axles. The TCCU monitors
the propeller shaft speeds, operating range (high/low),
and ABS activity and then applies a calculated amount
of torque to the front axle by pulse width modulating
(PWM) the current applied to the electromagnetic clutch
(EMC).
Touch-off Torque
The minimum EMC duty cycle is based on the vehicle
speed and throttle position. The TCCU receives the
throttle position (TP) sensor signal from the engine con
trol module (ECM) through CAN bus line.
Wheel Slip Detection and Control
The TCCU continuously monitors the front and rear pro-
peller shaft speeds to detect wheel slip.
When wheel slip is detected the TCCU controls the
EMC duty cycles as necessary until the wheel slip is
reduced below the allowable limit. The EMC duty cycle
will then be reduced to the touch-off value.Brake/ABS Strategy
When the ABS System is active, the EMC duty cycle
is set to a fixed duty cycle (30%) to aid in braking
without counteracting the ABS System.
4L Strategy
When the system is operating in 4WD low range, the
TCCU continues TOD
TM operation provided that the pro
peller shaft speed is below 175 rpm (5220 pulses/min-
ute). When the speed increases above 175 rpm, the
EMC duty cycle is set to the maximum value (88 %)
which applies the maximum available torque to the front
axle.
Position Encoder
The position encoder is used by the TCCU to determine
the position of the shift motor. Each motor position is
identified by a position code as shown.
Motor Position
Left Stop
Left of High
High
Right of High
Zone 1
Neutral
Zone 2
Low
Right Stop Position code 1/2/3/4
1111
1010
0010
0000
1110
1001
0001
0101
0100
Notice:
All other position codes are invalid
Position input : open circuit (> 4.5V) = 1
Position input : Shorted to speed/position return
(< 0.5V) = 0
Position Sensor Interpretation
1. When the module powers up, it will read the position
sensor and the 4H/4L switch input and respond to
the possible codes as following tables.
2. A command to shift will only be acted upon if the
TCCU is reading a valid code at the time the com-
mand to shift is made.
3. After a shift has started, the TCCU will power the
shift motor until the code for the requested position
is read. If an invalid code is read, the TCCU will go
into a default mode.
4. During a shift attempt, the shift motor will be ener-
gized for a maximum of 5 second

SSANGYONG MY2002
5D1-6 TRANSFER CASE
4H
4H
4H
4H
4H
4H
4H
4H
4H
4H
4H
4H
4H
4H
4H
4H
4H
4HLeft Stop
Left of High
High
Right of High
Zone 1
Neutral
Zone 2
Low
Right Stop
Left Stop
Left of High
High
Right to High
Zone 1
Neutral
Zone 2
Low
Right stopNo action required. 4WD LOW indicator off.
Blink 4WD LOW indicator.
After the shift conditions are input, attempt a shift to 4H mode if follow-
ing conditions are maintained for 2 seconds conditions are maintained
for 2 seconds.
Shift lever position is in neutral.
The speed of front and rear propeller shaft is below 87 rpm.
After successfully shifting into 4L mode, stop blinking 4WD LOW indicator.
Blink 4WD LOW indicator.
After the shift conditions are input, attempt a shift to 4L mode if following
conditions are maintained for 2 conditions are maintained for 2 seconds.
Shift lever position is in neutral.
The speed of front and rear propeller shaft is below 87 rpm.
After successfully shifting into 4L mode, stop blinking 4WD LOW indicator.
No action required. 4WD LOW indicator on.
4H/4L Switch
InputAction Motor Position

TRANSFER CASE 5D1-11
SSANGYONG MY2002
DIAGNOSIS
While the transfer case control unit (TCCU) is active it
periodically monitors its inputs and outputs. If a fault
is detected the 4WD CHECK lamp is illuminated and a
fault code is stored in the TCCU memory.
When requested, fault codes are downloaded to scan
tool through a diagnostic connector (K-line) serial com
munication.
SELF-DIAGNOSTIC TESTS
TCCU Internal Function
When the ignition is turned on the TCCU tests its read
only memory (ROM) and random access memory
(RAM). If there is a fault, the TCCU immediately resets
itself and re-tests the ROM and RAM. If the fault
persists the TCCU continues to reset and re-test until
the fault is corrected or the ignition is turned off. All
TCCU functions are inhibited until the fault is corrected.
The 4WD CHECK lamp is not illuminated if there is a
ROM or RAM fault.
If the ROM/RAM passes the electronically erasable
programmable read only memory (EEPROM) is tested.
If there is a fault the 4WD CHECK lamp is illuminated
and the TCCU continues to operate using the default
calibration data stored in ROM. Fault codes are not
stored when there is an EEPROM fault.
An EEPROM fault can only be cleared by cycling
ignition OFF-ON.
Shift Motor Assembly Test
If the TCCU detects a shift motor or position encoder
fault continuously for one second the 4WD CHECK
lamp is turned on and the appropriate fault code is
stored in memory.
1. A shift motor fault when the motor is off is defined
as follows:
Motor HI-LO circuits are shorted to ground.
Motor LO-HI circuits are shorted to ground.
Motor circuits are open.
2. A shift motor fault when the motor is energized is
defined as follows:
Motor HI-LO circuits are shorted to ground.
Motor LO-HI circuits are shorted to ground.
Motor HI-LO circuits are shorted to motor LO
HI circuits.
Motor circuits are open.
3. A position encoder fault is defined as follows:
Any position code which does not correspond
to the valid 9 codes.
A short to ground on any of the encoder lines.
4. If no shifts are in progress when a failure occurs
the TCCU will not respond to any shift commands.5. If a shift command has been received but not
acted upon when a failure occurred the TCCU
would cancel the command and not respond to
any subsequent shift commands.
6. If a shift command is in progress when an invalid
position code is confirmed it will be halted and
the TCCU will turn the motor toward the high
position. Afterwards the TCCU will not respond to
any shift commands.
7. If the shift motor or position encoder assembly
failures, other than a motor failure which occurs
when the motor is energized, recovers continuously
for one second the TCCU will function normally.
The 4WD CHECK lamp is turned off but the fault
code will remain in memory.
8. A motor failure (i.e. open or short circuit) which
occurs when the motor is energized can only be
cleared by cycling the ignition OFF-ON.
Front Speed Sensor Test
If a front speed sensor fault is detected continuously
for 0.5 second the 4WD CHECK lamp is illuminated.
The TCCU then responds as follows:
1. If the system is in high range the TCCU uses the
rear speed sensor to determine the EMC touch off
level and wheel slip control is suspended.
2. If the system is in low range, the EMC duty cycle
is set to maximum, independent of vehicle speed,
until the system is shifted out of low range.
3. All electric shift activity is halted until the Ignition
is cycled. If a shift is in progress it will be
completed.
If the front speed sensor recovers continuously for O.5
second the TCCU will function normally. The 4WD
CHECK lamp is turned off but the fault code will remain
in memory.
Rear Speed Sensor Test
If a rear speed sensor fault is detected continuously
for 0.5 second the 4WD CHECK lamp is illuminated.
The TCCU then responds as follows:
1. If the system is in high range the TCCU uses the
front speed sensor to determine the EMC touch
off level and wheel slip control is suspended.
2. If the system is in low range, the EMC duty cycle
is set to maximum independent of vehicle speed
until the system is shifted out of low range.
3. All electric shift activity is halted until the Ignition
is cycled. If a shift is in progress it will be
completed.
4. If the rear speed sensor recovers continuously for
0.5 second the TCCU will function normally. The
4WD CHECK lamp is turned off but the fault code
will remain in memory.

SSANGYONG MY2002
5D1-12 TRANSFER CASE
Both Speed Sensor Faulty
If both the front and rear speed sensors are faulty con
tinuously for 0.5 seconds the 4WD CHECK lamp is
illuminated. The TCCU then responds as follows:
1. If the system is in high range the TCCU sets the
EMC touch off level based on a vehicle speed of
0 and wheel slip control is suspended.
2. If the system is in low range, the EMC duty cycle
is set to maximum until the system is shifted out
of low range.
3. All electric shift activity is halted until the Ignition
is cycled. If a shift is in progress it will be
completed.
If both speed sensors recover continuously for 0.5 sec-
ond the TCCU will function normally. The 4WD CHECK
lamp is turned off but the fault code will remain in
memory.
Electro-Magnetic Clutch Test
The electromagnetic clutch (EMC) is tested for open
circuit or short circuit to ground. If a fault is detected
continuously for 0.8 second the 4WD CHECK lamp is
turned on and all TODTM activity is halted.
If the EMC recovers continuously for 0.8 second the
TCCU will function normally. The 4WD CHECK lamp is
turned off but the fault code will remain in memory.
DIAGNOSTIC TROUBLE CODES
(DTCS)
When a fault is detected a diagnostic trouble code
(DTC) is stored in the TCCU and illuminates the 4WD
CHECK indicator. This DTC will remain in memory until
the TCCU is instructed to erase DTCs by scan tool.
Notice: DTCs can not be erased by disconnecting of
power supply to the TCCU.
Diagnostic Trouble Codes Table
CLEARING DIAGNOSTIC
TROUBLE CODES
When diagnose by scan tool, it is required that you
make adequate service on defects against all fault
codes. And then you should delete the memorized fault
codes in transfer case control unit (TCCU) using scan
tool as follows;
1. Connect a scan tool with dada link connector
(DLC).
2. Select TROUBLE CODE CLEAR in scan tool.
3. In TROUBLE CODE CLEAR screen, press ENTER
key to erase the fault code.
Description
EEPROM Checksum Fault
TP Sensor Loss of Signal
TP Sensor Out of Range
Electro-Magnetic Clutch Open / Short
to Battery
Electro-Magnetic Clutch Short to
Ground
Front Speed Sensor Voltage Low
Front Speed Sensor Voltage High
Rear Speed Sensor Voltage Low
Rear Speed Sensor Voltage High
Speed Sensor Reference Voltage Low
Speed Sensor Reference Voltage
High DTC
1714
1715
1716
1721
1722
1731
1732
1733
1735
1736
1741
Description
Motor Open / Shorted to Battery
Motor Output Shorted to Ground
Shift System Timeout
General Position Encoder Fault (In-
validCode)
Position 1 Shorted to Ground
Position 2 Shorted to Ground
Position 3 Shorted to Ground
Position 4 Shorted to Ground DTC
1742
1714
1743
1750
1751
1752
1753
1754

SSANGYONG MY2002
5D1-14 TRANSFER CASE
4WD CHECK INDICATOR STAYS ON WITH IGNITION SWITCH ON
KAA5D040
Circuit Description
When the ignition switch turns to ON the transfer case
control unit (TCCU) illuminates 4WD CHECK and 4WD
LOWindicator to check bulb operation and turns off
after 0.6 seconds. Then TCCU starts self-diagnosis
and illuminate 4WD CHECK indicator when TCCU
detects any fault.
Diagnostic Aids
If the 4WD CHECK indicator illuminates steadily the
TCCU may detect some fault. TCCU should be
checked by scan tool to solve the problem.
The 4WD CHECK indicator also illuminates steadily
if the terminal B2 of TCCU connector is shorted to
ground. The shorted wire or terminals should be re-
paired.
Test Description
The number(s) below refer to step(s) on the diagnostic
table.
2. This step, along with step 4, checks the short to
ground condition of the wire or terminals
Step
1
ABS INDICATOR LAMP ILLUMINATED CONTINUOUSLY, NO DTCs STORED
Action Yes
Go to the
specific DTC
diagnostic tableNo
Go to Step 2 Value(s)
1. Turn the ignition switch to OFF.
2. Connect the scan tool to the data link connector
(DLC).
3. Turn the ignition switch to ON and request the DTC.
Does the scan tool display any DTC?