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 stored
when 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 Ground
Motor L-H shorted to Ground
Motor open circuit
b. A shift motor fault when the motor is energized is defined as follows:
Motor H-L shorted to Ground
Motor L-H shorted to Ground
Motor 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.
5D2-16 TRANSFER CASE (TOD)
g. If the shift motor/position encoder assembly failure (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.
h. 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.
3. 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:
a. 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.
b. 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 4L.
c. 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.
4. 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:
a. 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.
b. 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 4L.
c. All Electric Shift activity is halted until the Ignition is cycled. If a shift is in progress it will be completed.
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.
5. Both Speed Sensor Faulty
If both the Front and Rear Speed Sensors are faulty continuously for 0.5 seconds the “4WD CHECK” lamp is
illuminated. The TCCU then responds as follows:
a. 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.
b. If the system is in Low Range, the EMC Duty Cycle is set to maximum until the system is shifted out of 4L.
c. 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 second the TCCU will function normally. The “4WD CHECK”
lamp is turned off but the fault code will remain in memory.
6. EMC Test
The 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.
TRANSFER CASE (TOD) 5D2-19
Classification
Engine Type
Transmission/Vehicle Type
Axle Ratio
Tire Size
Coding Required
1. Replacement of TOD control unit.
2. Adjustment by input error.
3. Change of tire specification.
Items
Gasoline Engine (E32)
661 Diesel Engine
661LA Diesel Turbo Engine
662 Diesel Engine
662LA Diesel Turbo Engine
Manual Transmission
Automatic Transmission
MUSSO
KORANDO
3.73
4.55
4.89
5.38
5.86
P215
P235
P255
P275
Coding Method
1. Check and record engine type, axle ratio and tire size.
2. Ignition “OFF”.
3. Connect SCANNER with diagnosis connector in engine
room.
4. Ignition “ON”.
5. Read the current memorized specification in TOD control
unit.
6. Compare memorized specification with the checked record.
If not matched, perform a coding.
7. Read again memorized coding specification in TOD control
unit for confirmation of coding.
8. Check coding specification whether it matches with vehicle
or not. If not, perform a coding again.
Coding items
TRANSFER CASE (TOD) 5D2-21
DIAGNOSIS
Malfunction interior TOD control unit ; fault code
1714
lPhenomenon
1. When ignition “ON”, “4WD CHECK” lamp illuminates
continuously.
2. On diagnosis by SCAN-100, it displays fault code “1714”.
lCause ; Error of EEPROM checksum in TOD control unit
Test Stage / Contents
Result
Stage Test Contents and ProcedureSpecified Value
/Yes/NoCountermeasure
Check power supply for TOD control unit.
1. Disconnect 30 pin connector from TOD control unit.
2. Ignition “ON”.
3. Using multi-tester, measure voltage between pin 5(+)
and 17/18 (-).
- Specified value
- Measured value is within specified range ?11-14 Vdc
Ye s
NoPerform A2 stage
Perform A3 stage
Check connection status in TOD control unit connector.
1. Check connection status.
- Is it connected exactly?
2. In case of mal-connection, connect tightly then perform
the follows.
a. Delete fault code using Scan-100.
b. Ignition “OFF”.
c. Ignition “ON”.
d. Diagnose by Scan-100.
- Does it display fault code “1714”?Ye s
No
Ye s
No
Check short of 10A fuse (fuse No.20).
1. Detach No.20 fuse from engine room fuse box.
2. Check the existence of short.
- Is fuse normal? Yes
No
Check ground of TOD control unit.
1. Ignition “ON”.
2. Check voltage between 4/19 (+) pin and 17/18 (-)
using multi-tester (keep connection status).
- Specified value (battery is good)
- Measured value
3. Check short between 17/18 pin and body after
disconnect 30 pin connector.
- Is resistance "¥"?12Vdc (battery
voltage)
Ye s
No
Ye s
No A1
A2
A3
A4
Perform A3 stage
Perform A2 stage
Perform A3 stage
Normal system
Perform A4 stage
Replace fuse, then
perform A1 stage
Perform A4-3 stage
Replace TOD control
unit
Repair ground wiring
Ground is O.K.,
perform A5 stage
5D2-22 TRANSFER CASE (TOD)
Check function of TOD control unit.
1. Even A1, A2, A3 and A4 test, if you could not find defect,
it is required to replace TOD control unit on basis of
below phenomena.
a. ”4WD CHECK” lamp illuminates continuously when
ignition “ON”.
b. Shift is not possible even 4H/4L switch operation.
c. Upon diagnosis by Scan-100, it displays on
“impossible communication with TOD control unit”
or fault code “1714, 1715, 1716”.
- Do occur the above defects? Yes
NoReplace TOD control
unit
Normal system A5Test Stage / Contents
Result
Stage Test Contents and ProcedureSpecified Value
/Yes/NoCountermeasure
TRANSFER CASE (TOD) 5D2-23
Error of signal in engine throttle position ; fault
code 1715, 1716
lPhenomenon
1. Upon diagnosis by SCAN-100, it display on 1715,
1716 codes.
lCause
1. Bad communication line between E/G ECU and CAN.
2. Defect of TOD control unit.
3. Defect of E/G ECU.
Check connection status of connector through CAN
communication line.
1. Check connection of connector.
- Does connector connect correctly between TOD
control unit and E/G ECU?
2. In case of bad connection, connect correctly then
perform the follows ;
a. Delete the memorized fault code using SCANNER.
b. Ignition “OFF”.
c. Ignition “ON”.
d. Diagnose by SCANNER.
- Does it display fault codes “1715” or “1716”.Ye s
No
B1
Ye s
No
Check connection status of CAN communication line towards
E/G ECU.
1. Ignition “OFF”.
2. Disconnect 30 pin connector towards TOD control unit.
3. Measure resistance between pin No.22 and 23 in wiring
connector using multi-tester.
- Specified value
- Measured value is within specified range? B2
115-125W
Ye s
No
Check connection status of CAN communication line towards
TOD control unit.
1. Ignition “OFF”.
2. Disconnect coupling of E/G ECU (gray, 1-60 pin).
3. Measure resistance between pin No.37 and 38 in
coupling using multi-tester.
- Specified value
- Measured value is within specified range? B3
115-125W
Ye s
No Test Stage / Contents
Result
Stage Test Contents and ProcedureSpecified Value
/Yes/NoCountermeasure
Perform B2 stage
Perform B1-2 stage
Perform B2 stage
Normal system
Perform B3 STAGE
Perform B4 stage,
check and replace E/
G ECU
Perform B5 STAGE
Replace TOD control
unit
5D2-24 TRANSFER CASE (TOD)
Ye s
No B4
B5
Ye s
No
B6
4.75-5.25Vdc
Ye s
No
B70.3-0.9Vdc
4.6-4.9Vdc
Ye s
No
4.6-4.9Vdc
0.3-0.9Vdc
Ye s
No Test Stage / Contents
Result
Stage Test Contents and ProcedureSpecified Value
/Yes/NoCountermeasure
Check CAN communication line by diagnosis of E/G ECU.
1. Diagnose E/G ECU with SCANNER.
2. Does it display on fault code “27” ?
Check power supply and signal output on throttle valve
position sensor (potentiometer) 1,2.
1. Diagnose E/G ECU with SCANNER.
- Fault codes : 104, 105, 108, 109, 119, 185
Does it display on above code ?
Check power supply (5V) of throttle valve position sensor.
1. Ignition “ON”
2. Measure voltage between pin 112(+) and 84(-) keeping
coupling connection status using multi - tester.
- Specified value
- Measured value is within specified range ?
Check output signal from throttle position sensor 1 and 2.
1. Keep E/G idle status.
2. Measure output voltage between pin 87 (+) and 84 (-)
keeping E/G ECU coupling connection status using multi-
tester. (potentiometer 1)
- Specified value min. acc. Pedal
max. acc. Pedal
- Measured value is within specified range ?
3. Measure output voltage between pin 85 (+) and 84 (-)
keeping E/G ECU coupling connection status using multi-
tester. (potentiometer 2)
- Specified value min. acc. Pedal
max. acc. Pedal
- Measured value is within specified range ?
Replace TOD control
unit
Replace throttle body
actuator or check
cable Perform B1, B2, B3
stages
Perform B5 stage
Perform B6 stage
Replace TOD control
unit or perform A1-
A5 stages
Perform B7 stage
Replace E/G ECU or
perform B1-2 stage
after checking cable.
Perform B7-3 stage
Replace throttle body
actuator or check
cable.
TRANSFER CASE (TOD) 5D2-25
Error in electro - magnetic clutch : fault code
“1721”, “1722”
lPhenomenon
1. Upon diagnosis by SCAN-100, it displays on fault
codes “1721,1722”.
lCause
1. Defect in electro - magnetic clutch
2. Defect in connector or wiring
- Open or short from EMC to the supply : 1721
- Short EMC to ground : 1722
Ye s
No
C1
Ye s
No Ye s
No
11-15Vdc
Ye s
No
C2
Ye s
No
Test Stage / ContentsResult
Stage Test Contents and ProcedureSpecified Value
/Yes/NoCountermeasure
Check relevant connector connection status.
1. Check relevant connector connection status with TOD
control unit.
- Does it connect correctly ?
2. Check connection status of speed sensor and clutch
coil connector (7 pin) in transfer case.
- Does it connect correctly ?
3. In case of bad connection, connect it correctly then
perform the follows :
a. Delete the memorized fault code in control unit with
Scan - 100.
b. Ignition “OFF”.
c. Ignition “ON”.
d. Diagnose by SCAN-100
- Does it display on fault codes “1721,1722” ?
Check supply voltage into electro-magnetic clutch.
1. Ignition “ON”
2. Measure voltage between pin 4/19(+) and 17/18(-) in
TOD control unit connector.
- Specified value
- Measured value is within specified range ?
3. If the specified value would not be measured, perform
the follows :
a. Check battery voltage (charging condition)
b. Check open circuit on No.13 fuse (20A)
c. Check relevant wires.
- Is the above 3a, 3b, 3c normal ?Perform C1-2 stage
Perform C1-3 stage
Perform C2 stage
Normal system Perform C2 stage
Perform C1-3 stage
Perform C3 stage
Perform C2-3 stage
Perform C3 stage
lCharging/
Replace battery
lReplace fuse
lRepair wires