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
5D1-14 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?
TRANSFER CASE 5D1-15
SSANGYONG MY2002
Step
2
3
4
5Action
Yes
Go to Step 3
System OK
Go to Step 5
System OKNo
Go to Step 4
-
System OK
- Value(s)
1. Turn the ignition switch to OFF.
2. Disconnect the 18-pin connector from transfer case
control unit (TCCU).
3. Turn the ignition switch to ON and check the 4WD
CHECK bulb operation.
Does the 4WD CHECK indicator come on steadily?
Repair any short to ground circuit between terminal
B2 of TCCU connector and terminal A4 of cluster.
Is the repair complete?
1. Turn the ignition OFF.
2. Check the pin or terminals for damage or improper
connection.
3. Reconnect all the connectors.
4. Turn the ignition ON.
Does the 4WD CHECK indicator come on steadily?
Replace the TCCU.
Is the repair complete?
SSANGYONG MY2002
5D1-16 TRANSFER CASE
KAA5D040
NO 4WD LOW INDICATOR STAYS ON WITH IGNITION SWITCH ON
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 LOW indicator illuminates steadily the
transfer case in 4 wheel drive low range and 4H/4L
switch set to 4L. It is normal condition.
The 4WD LOW indicator also illuminates steadily if
the terminal B9 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 checks for the normal bulb operation.
Step
1
2
Action Yes
Go to Step 2
System OKNo
Go to Step 3
- Value(s)
Check the position of 4H/4L switch.
Does the 4H/4L switch set on 4L.
1. Turn the ignition switch to ON.
2. Set the shift lever to N (neutral).
3. Turn the 4H/4L switch to 4H.
Does the 4WD LOWindicator go off?
TRANSFER CASE 5D1-17
SSANGYONG MY2002
Step
3
4
5
6
7ActionYes
Go to Step 4
System OK
Go to Step 6
System OK
System OKNo
Go to Step 5
-
System OK
Go to Step-7
- Value(s)
1. Turn the ignition switch to ON.
2. Set the shift lever to N (neutral).
3. Turn the 4H/4L switch to 4L.
Does the 4WD LOWindicator go off?
The wiring of 4H/4L switch is reversed. Repair the
wiring.
Is the repair complete?
1. Turn the ignition OFF.
2. Check the pin or terminals for damage or improper
connection.
3. Reconnect all the connectors.
4. Turn the ignition ON.
Does the 4WD LOW indicator come on steadily?
Repair any short to ground circuit between terminal B9
of TCCU connector and terminal A8 of cluster.
Is the repair complete?
Replace the TCCU.
Is the repair complete?
TRANSFER CASE 5D1-67
SSANGYONG MY2002
KAA5D260
KAA5D270
TRANSFER CASE CONTROL UNIT
(TCCU)
Removal and Installation Procedure
1. Turn the ignition switch to OFF.
2. Disconnect two connectors from the TCCU under
the driver seat.
3. Remove two bolts and the TCCU.
Installation Notice
Tightening Torque 10 Nm (7 lb-ft)
When replacing the TCCU, it is required to a
cod-ing correspondent with the vehicle
specification. Refer to “TCCU Coding” in this
section.
4. Installation should follow the removal procedure
in the reverse order.
TRANSFER CASE
Removal and Installation Procedure
1. Disconnect the negative battery cable.
2. Lift the vehicle and make sure safety.
Notice: Be careful not to touch the catalytic
converter which is very hot after driving or engine
running.
3. Remove the drain plug and drain the transfer case
oil. Refer to “Oil Replacement” in this section.
Installation Notice
4. Disconnect the transmission extension wiring con-
nector on backside of transfer case.
5. Disconnect shift motor and clutch coil connector
(black 7 pin) on upper backside of transfer case.
6. Disconnect front and rear speed sensor connector
(white 7 pin).
7. Disconnect speedometer sensor connector.
Tightening Torque19 - 30 Nm
(14 - 22 lb-ft)
TRANSFER CASE (PART TIME - 4408) 5D2-11
SSANGYONG MY2002
KAA5D080
KAA5D090
KAA5D100
SELF-DIAGNOSIS TEST
System Description
1. TCCU detects transfer case system malfunctions
and indicates malfunctioning part(s) through
flashing 4H, 4L indicator lights.
Using a service connector, connect it to the
diagnosis box in under instrument pannel and read
the flashing of the “4WD CHECK” indicator light.
The flashing indicator light will show you defective
code(s).
2. Identify 7 defective codes after reading the
flashing indicator light.
TCCU
Shift motor
Magnetic synchronizer clutch
Speed sensor
Hub solenoid
Selector switch
Motor position sensor
KAA5D110
3. Transfer case system is malfunctioning when:
4H, 4L indicator lights are remain on after 0.6
second when turning the ignition switch ON.
4H, 4L indicator lights are continuously come
on during driving.
4. If only 1 part is malfunctioning, 4WD CHECK
indicator light will display defective code 3 times
continuously.
5. If more then 2 part is malfunctioning, the first
malfunctioning part will be displayed 3 times and
following malfunctioning parts will be displayed .
6. To read defective code, connect the service
connector and turn the ignition switch ‘ON’.
7. After repairing, eliminate the defective code stored
in the TCCU.
Notice: Before replacing the malfunction parts with
defective code, check the wires and connectors
for proper condition.