2003 SSANGYONG MUSSO Service Manual

5D2-8 TRANSFER CASE (TOD)Position Code 1/2/3/4 111 0
1010 0010 0000 111 0
Initial Operation of TOD Control Unit When ignition
“ON ”, “4L ” and "4WD check" lamps illuminates
for 0.6second to check bulb in instrument panel, then perform diagnosis of system. Position Encoder The Position Encoder is used by the TCCU to determine the
position of the Shift Motor. Each motor position is identified bya position code as shown. Notice
1. All other position codes are invalid
2. Position Input Open Circuit (> 4.5V) = 1
3. Position Input shorted to Speed/Position Return (< 0.5V) = 0
Motor Position
Left Stop
Left of High
High
Right of High Zone 1 Position Code 1/2/3/4
1001 0001 0101 0100 Motor Position
NeutralZone 2
Low
Right Stop

TRANSFER CASE (TOD) 5D2-9
4H/4L Switch Input4H 4H 4H 4H 4H 4H4H4H4H
4L 4L 4L4L 4L 4L4L4L 4L
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 follows
2. A command to shift will only be acted upon if the TCCU is reading a valid code at the time the command to shift ismade.
3. After a shift has started, the TCCU will power the shift motor until the code for the requested position is read. If an invalidcode is read, the TCCU will go into a default mode.
4. During a shift attempt, the shift motor will be energized for a maximum of 5 seconds. Motor Position
Left Stop
Left of High
High
Right of High
Zone 1
Neutral
Zone 2 Low
Right Stop
Left Stop
Left of High High
Right of High
Zone 1
Neutral Zone 2 Low
Right Stop Action
No action required. 4L bulb off. No action required. 4L bulb off. No action required. 4L bulb off. Blink 4L bulb. After the shift conditions are met, attempt a shiftto 4H under conditions of below 87 rpm in front and rearpropshaft and “Neutral ” position. After succesfully shifting into
4H, stop blinking 4L bulb. Same as above Same as aboveSame as aboveSame as aboveSame as above Blink 4L bulb. After the shift conditions are met, attempt a shift to 4L. After succesfully shifting into 4L, stop blinking 4L bulb.Same as aboveSame as aboveSame as above Same as above Same as aboveSame as aboveNo action required. 4L bulb on. No action required. 4L bulb on.

5D2-10 TRANSFER CASE (TOD) 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, neutral switch, speed sensors, position encoder, and ignition switch. A range change is initiated when
1. The 4H/4L Switch is changed from 4H to 4L or from 4L to 4H.
2. The motor position (as indicated by the position encoder) does not match the 4H/4L Switch immediately after theignition is turned on.
1. 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, theTCCU will attempt a range change after the following shift criteria are met:
a. The transmission is in neutral for 2 seconds after the shift is requested.
b. Both propshaft speeds are below 87 rpm (2580 pulses/minute).
If the transmission is taken out of neutral before 2 seconds has elapsed, or either propshaft 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.
2. Range Change When the shift criteria are met, the motor is rotated in the appropriate direction (as determined by the selectorswitch) until one of the following occurs:
a. The motor reaches its destination.
b. The motor is on for 5 seconds without reaching its destination. The shift has failed and the TCCU will respond as default mode.
c. 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, propshaft speeds, and transmission neutral inputs are ignored.
3. Indicator Function Once a range change has been initiated the 4L 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 4L Indicator will be illuminated if the motor is in Low and it will be turned off if the motor is in High. 4L Indicator illuminates as below figure.
 4H
4L
@ : shift is completed
 4L
4H
@ : shift is completed

TRANSFER CASE (TOD) 5D2-11
4. Electric Shift Default ModeIf the motor fails to reach its destination, the TCCU will attempt the following (in order):
a. The TCCU will wait 3 seconds then attempt the shift again.
b. If the second attempt to reach the destination fails the TCCU will wait 3 seconds then attempt to rotate the motor back to the original position. If successful, all future shifts will be inhibited until the Ignition is cycled.
c. If the attempt to return to the original position fails, the TCCU will wait 3 seconds then attempt to rotate the motor to the original position again. If the second attempt to return to the original position is successful, the “4WD CHECK ” lamp will be illuminated, and all future shifts will be inhibited until the Ignition is cycled.
d. If the second attempt to return to the original position fails the motor will be turned off, the “4WD CHECK ” lamp
will be illuminated, and all future shifts will be inhibited until the Ignition is cycled.
TOD TM
System Operation
The TOD TM
System is responsible for distributing torque between the front and rear axles. The TCCU monitors the
propshaft speeds, operating range (High/Low), and ABS activity and then applies a calculated amount of torque tothe front axle by Pulse Width Modulating the current applied to the EMC.
1. Touch-off Torque
The minimum EMC Duty Cycle is based on the vehicle speed and throttle positionThe TCCU receives the TPS signal from the following sources:On vehicles equipped with CAN, the TCCU receives the TPS signal from the CAN bus.
2. When Slip Detection
The TCCU continuously monitors the front and rear propshaft speeds to detect wheel slip.
3. Wheel Slip Control When wheel slip is detected the TCCU controls the EMC duty cycle 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.
4. 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.
5. 4L Strategy When the system is operating in 4L, the TCCU continues TOD TM
(operation provided that the propshaft speed is
below 175 rpm (5220 pulses/minute)). When the speed increases above 175 rpm, the EMC Duty Cycle is set tothe maximum value (88%) which applies the maximum available torque to the front axle.

5D2-12 TRANSFER CASE (TOD)Pin1 2345 6 78
Function
Motor HI-LO Motor LO-HI EMC
Battery (+)
Ignition
Position Return
Diagnosis Display - Pin
9
10 11
1213 14 1516 Function
HI / LO Switch Position 2
Front Speed
TPS Supply (Diesel) Speed/TPS Return
Motor HI-LOMotor LO-HI
Speed Reference Pin
1718192021 22 2324 Function
GroundGround
Battery (+) K-LINE
4L Illumination
CAN-HCAN-L
Auto T/M, Neutral Pin
2526272829 30 - - Function ABS Input
Brake Switch
Position 1 Position 3
Rear Speed
Position 4 --
TOD CONTROL UNIT
Shape and function of TOD Control Unit

TRANSFER CASE (TOD) 5D2-13
Speed Sensor/Clutch Coil and Motor Connector Speed senso /clutch coil and shift motor connector locate upper backside transfer case (upper part of shift motor).
- Shift motor connector : Black
- Speed sensor and clutch coil connector : White
Shift Mtor Connector Speed Sensor/Clutch Coil ConnectorRear View for Connector
Pin A B
CD
EF
G Function
Position 4Motor (Counter-Clockwise)Position 3Position 2 Position 1 Position RetumMotor (Clockwise) Pin
HI
J
K L
M N Function
Clutch Coil (EMC) Front Speed ReturnFront SpeedFront Speed Sensor Supply Rear Speed Sensor Supply Rear SpeedRear Speed Return
Rear View for Connector

5D2-14 TRANSFER CASE (TOD)


Motor HI-LO(clockwise)
Motor LO-HI(counterclockwise)
PIN 13
CONTROL UNIT DIAGRAM
TOD CONTROL UNIT
14

TRANSFER CASE (TOD) 5D2-15
DIAGNOSIS
While the 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 a diagnostic connector (K-line) serial communications using SCAN- 100. DIAGNOSTIC TESTS 1.TCCU Internal Function
When the Ignition is turned on the TCCU tests its ROM and 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 EEPROM memory 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 storedwhen there is an EEPROM fault.
An EEPROM fault can only be cleared by cycling ignition off-on.
2.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.
a. A shift motor fault when the motor is off is defined as follows:
Motor H-L shorted to GroundMotor L-H shorted to GroundMotor open circuit
b. A shift motor fault when the motor is energized is defined as follows: Motor H-L shorted to GroundMotor L-H shorted to GroundMotor H-L shorted to Motor L-H Motor open circuit
c. 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.
d. If no shifts are in progress when a failure occurs the TCCU will not respond to any shift commands.
e. If a shift command has been received, but not acted upon when a failure occurs the TCCU will cancel the command and not respond to any subsequent shift commands.
f. 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.