SECTION 3 POWER TRAIN SYSTEM

Group 1 Structure and Function 3-1

Group 2 Operational Checks and Troubleshooting 3-61
Group 3 Tests and Adjustments 3-72
Group 4 Disassembly and Assembly 3-75
 SECTION 3 POWER TRAIN SYSTEM
GROUP 1 STRUCTURE AND FUNCTION
1. POWER TRAIN COMPONENT OVERVIEW

Front drive shaft Center drive shaft Upper drive shaft Engine

Front axle Transmission Rear drive shaft Rear axle

7307PT01

The power train consists of the following components :

・Transmission
・Front, upper, center and rear drive shafts
・Front and rear axles
Engine power is transmitted to the transmission through the torque converter.
The transmission is a hydraulically engaged four speed forward, three speed reverse counter shaft type
power shift transmission. A disk type parking brake is located in the front axle.
The transmission outputs through universal joints to three drive shaft assemblies. The front drive shaft
is a telescoping shaft which drives the front axle. The front axle is mounted directly to the loader front
frame. The front axle is equipped with limited slip differential.
The rear axle is mounted on an oscillating pivot. The rear axle is equipped with conventional differential.
The power transmitted to front axle and rear axle is reduced by the pinion gear and ring gear of
differential. It then passes from the differential to the sun gear shaft(Axle shaft) of final drive.
The power of the sun gear is reduced by a planetary mechanism and is transmitted through the
planetary hub to the wheel.

3-1
 HYDRAULIC CIRCUIT

K4 KR K1 K3 KV K2

F 60 E 55 D 56 C 58 B 53 A 57
P1 P2 P3 P4 P5 P6
B D B D B D B D B D B D

Y1 Y2 NFS Y3 NFS Y4 NFS Y5 Y6 NFS

NFS NFS

Pressure
Temp reducing
sensor valve
9 bar
System
pressure
valve
Valve block control circuit 16+2 bar

Converter

Relief Filter
valve
9 bar
Oil cooler Bcak
pressure
valve
Bypass 3.5 bar Pump
valve 16+2 bar
1.5 bar

Oil sump
Lubrication
Main oil circuit

76043PT18

NFS Follow-on slide P3 Proportional valve clutch K1

D Oscillation damper P4 Proportional valve clutch K3
B Orifice P5 Proportional valve clutch KV
P1 Proportional valve clutch K4 P6 Proportional valve clutch K2
P2 Proportional valve clutch KR Y1~Y6 Pressure regulator

Current
Engaged Positions No. of the
Speed Forward Reverse Neutral clutch on the measuring
valve block points
1 2 3 4 1 2 3
Y1 X K4 F 60
Y2 X X X KR E 55
Y3 X X K1 D 56
Y4 X X X K3 C 58
Y5 X X X KV B 53
Y6 X X K2 A 57
Engaged
K1,KV KV,K2 K3,KV K4,K3 KR,K1 KR,K2 KR, K3 - - -
clutch
X : Pressure regulator under voltage

3-2
2. TORQUE CONVERTER

5 1 2 3 4

73033TM00

1 Turbine 3 Pump 5 Input flange

2 Stator 4 Transmission pump

The converter is working according to the Trilok-system, i.e. it assumes at high turbine speed the
characteristics, and with it the favorable efficiency of a fluid clutch.
The converter will be defined according to the engine power so that the most favorable operating
conditions for each installation case are given.
The Torque converter is composed of 3 main components :
Pump wheel - turbine wheel - stator(Reaction member)
These 3 impeller wheels are arranged in such a ring-shape system that the fluid is streaming through
the circuit components in the indicated order.
Pressure oil is constantly streaming out of the transmission pump through the converter. In this way, the
converter can fulfill its task to multiply the torque of the engine, and at the same time, the heat created in
the converter is dissipated through the escaping oil.
The oil, escaping out of the pump wheel, enters the turbine wheel and is there inversed in the direction
of flow.
According to the rate of inversion, the turbine wheel and with it also the output shaft, receive a more or
less high reaction moment. The stator(Reaction member), following the turbine, has the task to inverse
again the oil which is escaping out of the turbine and to delivery it under the suitable discharge direction
to the pump wheel.
Due to the inversion, the stator receives a reaction moment.
The relation turbine moment/pump moment is called torque conversion. This is the higher the greater
the speed difference of pump wheel and turbine wheel will be.
Therefore, the maximum conversion is created at standing turbine wheel.
With increasing output speed, the torque conversion is decreasing. The adaption of the output speed to
a certain required output moment is infinitely variable and automatically achieved by the torque
converter.

3-3
If the turbine speed is reaching about 80% of the pump speed, the conversion becomes 1.0 i.e. the
turbine moment becomes equal to that of the pump moment.
From this point on, the converter is working similar to a fluid clutch.
A stator freewheel serves to improve the efficiency in the upper driving range, it is backing up in the
conversion range the moment upon the housing, and is released in the coupling range.
In this way, the stator can rotate freely.

Function of a hydrodynamic torque converter(Schematic view)

TP = Torque of the pump wheel

TT = Torque of the turbine wheel
TR = Torque of the reaction member(Stator)
Pump wheel TR

Turbine wheel
From the engine
TT

TP

To the gearbox

Starting nT = 0
condition 1 Reaction member
1.5
(Stator) 2.5 Machine stopped

Intermediate
condition 1 <1.5
nT < n engine
<2.5

Condition shortly
before the converter 1 1 nT = 0.8n engine
clutch is closed. 0

Turbine wheel is running with

about the same speed as
pump wheel.

(760) 3-4

3-4
3. TRANSMISSION
1) LAYOUT

12

1
11

2
10

4
9

15

14

13
7607PT03

1 Reverse clutch(KR) 6 Rear output flange 11 Converter

2 Engine-dependent 7 Converter side output 12 Inductive transmitter
power take-off flange for engine speed
3 Forward clutch(KV) 8 Output shaft 13 4th clutch(K4)
4 2nd clutch(K2) 9 Transmission pump 14 Converter relief valve
5 3rd clutch(K3) 10 Input flange 15 1st clutch(K1)

3-5
 2) INSTALLATION VIEW

1 2 9 10 11 12 14

15

20

3 16
19
8

3 13 18

4 17

7 6 5

7407PT02

1 Lifting lugs 11 Breather

2 Input flange-input through universal shaft 12 Transmission-case cover
3 Transmission suspension threads M20 13 Transmission case
4 Output flange-converter side 14 Power take-off; Coaxial;
5 Oil drain plug with magnetic insert M38×1.5 Engine-dependent
6 Model identification plate 15 Electro-hydraulic control
7 Attachment possibility for oil level tube 16 Oil level tube with oil dipstick
with oil dipstick(Converter side) 17 Transmission suspension threads M20
8 Attachment possibility for emergency 18 Output flange-rear
steering pump 19 Exchange filter(Fine filter)
9 Cover 20 Filter head with connection for filter
10 Converter bell housing restriction switch

3-6
 3) OPERATION OF TRANSMISSION
(1) Forward
① Forward 1st
In 1st forward, forward clutch and 1st clutch are engaged.
Forward clutch and 1st clutch are actuated by the hydraulic pressure applied to the clutch piston.

KR KR
KV IN

K4
K2

INPUT

K3 K1

KV
OUT

GEAR PATTERN

K2

K1 K3

K4

OUTPUT OUTPUT

7607PT04

3-7
 ② Forward 2nd
In 2nd forward, forward clutch and 2nd clutch are engaged.
Forward clutch and 2nd clutch are actuated by the hydraulic pressure applied to the clutch
piston.

KR KR
KV IN

K4
K2

INPUT

K3 K1

KV
OUT

GEAR PATTERN

K2

K1 K3

K4

OUTPUT OUTPUT

7607PT05

3-8
 ③ Forward 3rd
In 3rd forward, forward clutch and 3rd clutch are engaged.
Forward clutch and 3rd clutch are actuated by the hydraulic pressure applied to the clutch piston.

KR KR
KV IN

K4
K2

INPUT

K3 K1

KV
OUT

GEAR PATTERN

K2

K1 K3

K4

OUTPUT OUTPUT

7607PT06

3-9
 ④ Forward 4th
In 4th forward, 4th clutch and 3rd clutch are engaged.
4th clutch and 3rd clutch are actuated by the hydraulic pressure applied to the clutch piston.

KR KR
KV IN

K4
K2
INPUT

K3 K1

KV
OUT

GEAR PATTERN

K2

K1 K3

K4

OUTPUT OUTPUT

7607PT07

3-10
 (2) Reverse
① Reverse 1st
In 1st reverse, reverse clutch and 1st clutch are engaged.
Reverse clutch and 1st clutch are actuated by the hydraulic pressure applied to the clutch piston.

KR KR
KV IN

K4
K2

INPUT

K3 K1

KV
OUT

GEAR PATTERN

K2

K1 K3

K4

OUTPUT OUTPUT

7607PT08

3-11
 ② Reverse 2nd
In 2nd reverse, reverse clutch and 2nd clutch are engaged.
Reverse clutch and 2nd clutch are actuated by the hydraulic pressure applied to the clutch
piston.

KR KR
KV IN

K4
K2

INPUT

K3 K1

KV
OUT

GEAR PATTERN

K2

K1 K3

K4

OUTPUT OUTPUT

7607PT09

3-12
 ③ Reverse 3rd
In 3rd reverse, reverse clutch and 3rd clutch are engaged.
Reverse clutch and 3rd clutch are actuated by the hydraulic pressure applied to the clutch piston.

KR KR
KV IN

K4
K2

INPUT

K3 K1

KV
OUT

GEAR PATTERN

K2

K1 K3

K4

OUTPUT OUTPUT

7607PT10

3-13
4) ELECTRO-HYDRAULIC SHIFT CONTROL WITH PROPORTIONAL VALVE

2 1 3

A A
Y6 Y1

Y5 Y2

B
Y4 Y3

3 6

2 6 1 4 11 9 10

Y5

SECTION A-A SECTION B-B

8 7
73033CV01

1 Pressure reducing valve(9bar) 7 Intermediate sheet

2 System pressure valve(16+2bar) 8 Duct plate
3 Housing 9 Oscillation damper
4 Cable harness 10 Follow-on slide
5 Cover 11 Pressure regulator
6 Valve block

Transmission control see schedule of measuring points, hydraulic schematic and electro-hydraulic
control unit at page 3-2, 3-14 and 3-73.
The six clutches of the transmission are selected through the 6 proportional valves P1 to P6. The
proportional valve(Pressure regulator-unit) consists of pressure regulator(e.g. Y1), booster valve
oscillation damper.
The pilot pressure of 9 bar for the control of the follow-on slides is created by the reducing valve.
The pressure oil (16+2bar) is directed through the follow-on slide to the corresponding clutch.

3 - 14
 By the direct proportional selection with separate pressure modulation for each clutch, the
pressures to the clutches, taking part in the gear change, are controlled. In this way, a hydraulic
overlab of the clutches to be engaged and disengaged is achieved.
This is leading to fast shiftings without traction force interruption.
At the shifting, the following criteria are considered:
- Speed of engine, turbine, central gear train and output.
- Transmission temperature.
- Shifting mode(Up-, down-, reverse shifting and gear engaging from neutral).
- Load level(Full- and partial load, traction, coasting inclusive consideration of load cycles during the
shifting).
The system pressure valve is limiting the maximum control pressure to 16+2 bar and releases the
main stream to the converter and lubricating circuit.
A converter relief valve is installed in the converter inlet, which protects the converter against high
internal pressures(Opening pressure 9bar).
Within the converter, the oil transfers the power transmission according to the well-known
hydrodynamic principle(See torque converter, page 3-3).
In order to avoid cavitation, the converter must be always completely filled with oil.
This is achieved by a converter back pressure valve, following the converter, with an opening
pressure of about 3.5bar.
The oil, escaping from the converter, is directed to a oil cooler.
The oil is directed from the oil cooler to the transmission and from there to the lubricating-oil circuit
so that all lubricating points are supplied with cooled oil.
In the electro-hydraulic control unit there are 6 pressure regulators installed.

5) GEAR SELECTOR(DW-3)
The gear selector is designed for the
mounting on the left side of the steering
column. The positions(Speeds) 1 to 4 are
F
selected by a rotary motion, the driving 1
2
3
N
4

direction Forward(F)-Neutral(N)-Reverse(R) R

by tilting the gear selector lever.

The gear selector is also available with
integrated kickdown control knob.
A neutral lock is installed as protection
against inadvertent drive off.
N D
Position N - Gear selector lever blocked in
this position.
Position D - Driving. 73033TM17

3 - 15
 6) LCD
Cluster 1( ) LCD
1
2( ) MENU
M 2 - Display main menu
MENU

- Return to the normal display

BACK
3
3( ) BACK
4
NEXT
Return to the previous menu
5
SELECT
4( ) NEXT
Move to the next selection
5( ) SELECT
77073CD72
Activate the currently chosen item

(1) Normal display

TYPE 1 TYPE 2

1
c
a e 3
2 d
b

6 4

5
77073CD73

No Symbol Meaning Remark

Forward, reverse, neutral LCD type 1, Display during AEB mode

F, R, N Forward, reverse, neutral LCD type 2, Display during AEB mode
1
1, 2, 3, 4 Actual gear -
P Parking brake mode active -
a Wiper motor intermittently operating -
2 When operating intermittently, it
b -
shows an operating time interval.
c, d Up and down shifting c : Forward, d : Reverse
3 Automatic mode
e Pre-selected gear -
HOUR

4 Hour meter Display the total operation hours of the machine

COOLANT
5 C Engine coolant temperature Display in accordance with selected items
AUT Ride control mode active Ride control switch AUTO position, see page 7-35
6 ON Ride control mode active Ride control switch ON position, see page 7-35
(Option)
OFF Ride control mode turn off Ride control switch MIDDLE position, see page 7-35
※ Both type1 and type2 are LCD modes and they can be changed each other by operator’s selection.

3 - 16
 (2) Display map

Normal Main menu Sub menu Activate item

Press MENU Press ACCESSORY Press ACCESSORY
M
ACCESSORY JOB TIMER JOB TIMER
CLOCK HOURMETER
ON
USER STOP WATCH
OFF
ADJUSTMENT ODOMETER
DIAGNOSTICS LIGHT CONT RESET

Previous Press Previous Press Previous Press

menu menu menu
77073CD74

Main group Sub group Meaning Display on LCD

Accessory ・Measure the various job time. JOB HOUR

Job timer
・Press : Display ON, OFF or RESET
・Measures time in seconds.
Stop watch -
・Press : Start. Press again : Stop.
LATEST-DIS
Latest ・Distance until recent times. Km
Odometer TOTAL-DIS
Total ・Total distance. Km

・Control of LCD display luminosity.

Light control -
・Brightness control : , .
Clock ・When 12H or 24H is selected, the current
Time set hour appears.
・ , : input, : setting.
PM
Clock ON/OFF ・ : Clock display ON or OFF.

1
・Alarm setting. It is possible to set 3 alarms.
Alarm 2
・Stop alarming : or buzzer stop switch.
3
User Mode 1 ・Automatic travelling speed is applied from 1st -
(1st-4th) to 4th gear.
Auto 1/2
Mode 2 ・Automatic travelling speed is applied from -
(2nd-4th) 2nd to 4th gear.
Mode 1 ・Press button once : Shift down, press button
Quick (Down/Up) again ; shift up. -
shift Mode 2 ・Press button every time : Shift to lower gear
(Down)
-
respectively.
Auto ・ON : Transmission auto condition.
Aux-sw Select ・OFF : Transmission semi-auto condition.
Clutch ・ON : Clutch cut-off is activated. -
Cut-off ・OFF : Clutch cut-off is cancelled.

3 - 17
 Main group Sub group Meaning Display on LCD display
Adjustment Unit ・Choose between metric and inch unit display.
TOTAL-DIS TOTAL-DIS

Km Mile

Wiper ・When using the intermittent function of wiper

Intermittence motor, it regulates operation time.
Pulse ・Press : Modification. -
・It controls the disk interval of the transmission,
AEB -
automatically.
・English : Display in English.
ENG/KOR -
・Korean : Display in Korean.
・Type 1 : Indicate with the symbol.
Display 1/2 ・Type 2 : Indicate with a letter. ,
Diagnostics Fault ・Error code display. -
Code ・Refer to page 3-19.
HYD BATT-VOLT

Machine ・Hydraulic temperature, battery voltage and C V

Monitor coolant temperature display. COOLANT

・Press : Display ON or OFF. C

Fault ・Error code display.

-
Transmis- Code ・Refer to page 3-22~48.
OIL TEMP
sion ・Transmission oil temperature display.
Monitor F
・Press : Display ON or OFF.
Version ・Cluster and CPU version display -

(3) Machine fault codes

When selecting the fault code menu, it shows all of the fault codes which mean abnormal
conditions of present time.

Press ※ To go out from fault explanation window,

press button.
030 Er : 030 (Press , to go out to first menu.)
050 ※ No error will be indicated in case that
025 there’s no fault.
046
Fuel level sensor open
or short to power

77073CD60

3 - 18
 Description Code Meaning Remark

010 Power input voltage low Below 18V

011 Power input voltage high Above 38V
012 Alternator voltage low Below 5V
Electrical 013 Alternator voltage high Above 36V
system 014 Buzzer circuit open or short to ground
015 Buzzer circuit short to power
016 Wiper relay open or short to ground
017 Wiper relay short to power
Hydraulic 020 Hydraulic oil temperature sensor open or short to power
system 021 Hydraulic oil temperature sensor short to ground
030 Fuel level sensor open or short to power
031 Fuel level sensor short to ground
032 Safety relay open or short to ground Restarting prevention
033 Safety relay short to power Restarting prevention
034 Cooling fan driving valve open or short to ground
Engine 035 Cooling fan driving valve short to power
system
040 Coolant temperature sensor open or short to power
041 Coolant temperature sensor short to ground
042 Preheater relay open or short to ground
043 Preheater relay short to power
044 Engine speed signal bad
050 Auto select switch supply power open or short to power
051 Auto select switch supply power short to ground
T/M system
052 Clutch cutoff supply power open or short to power
053 Clutch cutoff supply power short to ground Option
Steering 060 Emergency steering relay open or short to ground Option
system 061 Emergency steering relay short to power
070 MCU communication error
Communication
071 TCU communication error
080 Speedometer output signal(from TCU) bad
081 MCU memory error
Others 082 MCU clock error
083 MCU clock battery error
084 Monitor memory error
MCU : Machine control unit TCU : Transmission control unit

3 - 19
 (4) Display during AEB mode

Symbol Meaning Remarks

K1~K4, KV, KR Calibrating clutch K1~K4, KV

or KR respectively
- And Kx Wait for start, initialization of
clutch Kx, x : 1, 2, 3, 4, V, R
And Kx Fast fill time determination of
clutch Kx
= And Kx Compensating pressure
determination of clutch Kx
OK Calibration for all clutches Transmission stays in neutral, you have to restart the
finished TCU(Ignition off/on) after removing AEB-Starter
STOP AEB cancled(Activation Transmission stays in neutral, you have to restart the
stopped) TCU(Ignition off/on)
STOP and Kx AEB stopped, clutch Kx can't Transmission stays in neutral, you have to restart the
be calibrated TCU(Ignition off/on)
Spanner and Kx Kx couldn't be calibrated, AEB Transmission stays in neutral, you have to restart the
finished TCU(Ignition off/on)
△E Engine speed too low,
- Raise engine speed
▽E Engine speed too high,
- Lower engine speed
△T Transmission oil temperature
too low,
- Heat up transmission
▽T Transmission oil temperature
too high,
- Cool down transmission
FT Transmission temperature not Transmission stays in neutral, you have to restart the
in defined range during TCU(Ignition off/on)
calibration
FB Operating mode not NORMAL Transmission stays in neutral, you have to restart the
or transmission temperature TCU(Ignition off/on)
sensor defective or storing of
calibrated values to EEPROM
has failed
FO Output speed not zero Transmission stays in neutral, you have to restart the
TCU(Ignition off/on)
FN Shift lever not in neutral Transmission stays in neutral, you have to restart the
position TCU(Ignition off/on)
FP Park brake not applied Transmission stays in neutral, you have to restart the
TCU(Ignition off/on)
STOP AEB-Starter was used incorrect Transmission stays in neutral, you have to restart the
or is defective. Wrong device TCU(Ignition off/on)
or wrong cable used
AEB mode : It controls the disk internal of the transmission, automatically.
Refer to page 7-28, 29.

3 - 20
(5) Definition of operating modes
① Normal
There's no failure detected in the transmission system or the failure has no or slight effects on
transmission control. TCU will work without or in special cases with little limitations.(See
following table)
② Substitute clutch control
TCU can't change the gears or the direction under the control of the normal clutch modulation.
TCU uses the substitute strategy for clutch control. All modulations are only time controlled.
(Comparable with EST 25)
③ Limp-home
The detected failure in the system has strong limitations to transmission control. TCU can
engage only one gear in each direction. In some cases only one direction will be possible.
TCU will shift the transmission into neutral at the first occurrence of the failure. First, the operator
must shift the gear selector into neutral position.
If output speed is less than a threshold for neutral to gear and the operator shifts the gear
selector into forward or reverse, the TCU will select the limp-home gear.
If output speed is less than a threshold for reversal speed and TCU has changed into the limp-
home gear and the operator selects a shuttle shift, TCU will shift immediately into the limp-home
gear of the selected direction.
If output speed is greater than the threshold, TCU will shift the transmission into neutral. The
operator has to slow down the vehicle and must shift the gear selector into neutral position.
④ Transmission-shutdown
TCU has detected a severe failure that disables control of the transmission.
TCU will shut off the solenoid valves for the clutches and also the common power supply(VPS1).
Transmission shifts to neutral. The park brake will operate normally, also the other functions
which use ADM1 to ADM8.
The operator has to slow down the vehicle. The transmission will stay in neutral.
⑤ TCU-shutdown
TCU has detected a severe failure that disables control of system.
TCU will shut off all solenoid valves and also both common power supplies(VPS1, VPS2). The
park brake will engage, also functions are disabled which use ADM 1 to ADM 8.
The transmission will stay in neutral.

(6) Abbreviations
OC : Open circuit
SC : Short circuit
OP mode : Operating mode
TCU : Transmission control unit
EEC : Electronic engine controller
PTO : Power take off

3 - 21
 (7) Transmission fault codes
Fault code Int. code Meaning of the fault code
(Hex) (Dec) possible reason for fault detection Reaction of the TCU Possible steps to repair Remarks

11 48 Logical error at gear range signal TCU shifts transmission to •Check the cables from TCU to Failure cannot be detected in
TCU detected a wrong signal combination neutral shift lever systems with DW2/DW3 shift
for the gear range OP-mode : Transmission •Check signal combinations of lever
•Cable from shift lever to TCU is broken shutdown shift lever positions for gear Fault is taken back if TCU
•Cable is defective and is contacted to range detects a valid signal for the
battery voltage or vehicle ground position
•Shift lever is defective

12 46 Logical error at direction select signal TCU shifts transmission to •Check the cables from TCU to Fault is taken back if TCU
TCU detected a wrong signal combination neutral shift lever detects a valid signal for the
for the direction direction at the shift lever
•Cable from shift lever to TCU is broken OP-Mode : Transmission •Check signal combinations of
•Cable is defective and is contacted to shutdown shift lever positions F-N-R
battery voltage or vehicle ground
•Shift lever is defective

13 95 Logical error at engine derating device After selecting neutral, TCU •Check engine derating device This fault is reset after power
TCU detected no reaction of engine while change to OP mode limp home up of TCU
derating device active

15 176 Logical error at direction select signal 2 shift TCU shifts transmission to •Check the cables from TCU to Fault is taken back if TCU
lever neutral if selector active shift lever 2 detects a valid neutral signal
TCU detected a wrong signal combination OP mode : Transmission •Check signal combinations of for the direction at the shift
for the direction shutdown if selector shift lever positions F-N-R lever
•Cable from shift lever 2 to TCU is broken active
•Cable is defective and is contacted to
battery voltage or vehicle ground
•Shift lever is defective

16 178 Logical error at axle connection OP mode : Normal •Check the cables from TCU to
Feedback axle connection measured by TCU feedback axle connection switch
and output signal axle connection don't fit •Check signals of the feedback
•Axle can't be connected or disconnected axle connection switch
due to mechanical problem
•One of the cables from feedback axle
connection switch to TCU is broken

3-22
Fault code Int. code Meaning of the fault code
(Hex) (Dec) possible reason for fault detection Reaction of the TCU Possible steps to repair Remarks

21 32 S.C. to battery voltage at clutch cut off input Clutch cut off function is disabled •Check the cable from TCU to
The measured voltage is too high: OP mode : Normal the sensor
•Cable is defective and is contacted to •Check the connectors
battery voltage •Check the clutch cut off sensor
•Clutch cut off sensor has an internal defect
•Connector pin is contacted to battery voltage

22 29 S.C. to ground or O.C. at clutch cut off input Clutch cut off function is disabled •Check the cable from TCU to
The measured voltage is too low: OP mode : Normal the sensor
•Cable is defective and is contacted to •Check the connectors
vehicle ground •Check the clutch cut off sensor
•Cable has no connection to TCU
•Clutch cut off sensor has an internal
defect
•Connector pin is contacted to vehicle
ground or is broken

23 S.C. to battery voltage at load sensor input Retarder function is affected •Check the cable from TCU to Availability of retarder
The measured voltage is too high: TCU uses default load the sensor depends on default load
•Cable is defective and is contacted to OP mode : Normal •Check the connectors
battery voltage •Check the load sensor
•Load sensor has an internal defect •Check the assembly tolerances
•Connector pin is contacted to battery voltage of load sensor

24 S.C. to ground or O.C. at load sensor input Retarder function is affected •Check the cable from TCU to Availability of retarder
The measured voltage is too low: TCU use default load the sensor depends on default load
•Cable is defective and is contacted to OP mode : Normal •Check the connectors
vehicle ground •Check the load sensor
•Cable has no connection to TCU •Check the assembly tolerances
•Load sensor has as internal defect of load sensor
•Connector pin is contacted to vehicle
ground or is broken

3-23
Fault code Int. code Meaning of the fault code
(Hex) (Dec) possible reason for fault detection Reaction of the TCU Possible steps to repair Remarks

25 33 S.C. to battery voltage or O.C. at transmission No reaction, TCU use default •Check the cable from TCU to
sump temperature sensor input temperature the sensor
The measured voltage is too high: OP mode : Normal •Check the connectors
•Cable is defective and is contacted to •Check the temperature sensor
battery voltage
•Cable has no connection to TCU
•Temperature sensor has an internal defect
•Connector pin is contacted to battery
voltage or is broken

26 30 S.C. to battery voltage or O.C. at transmission No reaction, TCU uses default •Check the cable from TCU to
sump temperature sensor input temperature the sensor
The measured voltage is too low: OP mode : Normal •Check the connectors
•Cable is defective and is contacted to •Check the temperature sensor
vehicle ground
•Temperature sensor has an internal defect
•Connector pin is contacted to vehicle
ground

27 76 S.C. to battery voltage or O.C. at retarder No reaction, TCU uses default •Check the cable from TCU to
temperature sensor input temperature the sensor
The measured voltage is too high: OP mode : Normal •Check the connectors
•Cable is defective and is contacted to •Check the temperature sensor
battery voltage
•Cable has no connection to TCU
•Temperature sensor has an internal defect
•Connector pin is contacted to battery
voltage or is broken

28 74 S.C. to ground at retarder temperature No reaction, TCU uses default •Check the cable from TCU to
sensor input temperature the sensor
The measured voltage is too low: OP mode : Normal •Check the connectors
•Cable is defective and is contacted to •Check the temperature sensor
vehicle ground
•Temperature sensor has an internal defect
•Connector pin is contacted to vehicle ground

3-24
Fault code Int. code Meaning of the fault code
(Hex) (Dec) possible reason for fault detection Reaction of the TCU Possible steps to repair Remarks

27 76 S.C. to battery voltage or O.C. at converter No reaction, TCU uses default •Check the cable from TCU to
output temperature sensor input temperature the sensor
The measured voltage is too high: OP mode : Normal •Check the connectors
•Cable is defective and is contacted to •Check the temperature sensor
battery voltage
•Cable has no connection to TCU
•Temperature sensor has an internal defect
•Connector pin is contacted to battery
voltage or is broken

28 74 S.C. to ground at converter output No reaction, TCU uses default •Check the cable from TCU to
temperature sensor input temperature the sensor
The measured voltage is too low: OP mode : Normal •Check the connectors
•Cable is defective and is contacted to •Check the temperature sensor
vehicle ground
•Temperature sensor has an internal defect
•Connector pin is contacted to vehicle ground

31 38 S.C. to battery voltage or O.C. at engine OP mode : Substitute clutch control •Check the cable from TCU to
speed input the sensor
TCU measures a voltage higher than 7.00V •Check the connectors
at speed input pin •Check the speed sensor
•Cable is defective and is contacted to
battery voltage
•Cable has no connection to TCU
•Speed sensor has an internal defect
•Connector pin is contacted to battery
voltage or has no contact

32 34 S.C. to ground at engine speed input OP mode : Substitute clutch control •Check the cable from TCU to
TCU measures a voltage less than 0.45V at the sensor
speed input pin •Check the connectors
•Cable/connector is defective and is •Check the speed sensor
contacted to vehicle ground
•Speed sensor has an internal defect

3-25
Fault code Int. code Meaning of the fault code
(Hex) (Dec) possible reason for fault detection Reaction of the TCU Possible steps to repair Remarks

33 42 Logical error at engine speed input OP mode : Substitute clutch control •Check the cable from TCU to This fault is reset after power
TCU measures a engine speed over a the sensor up of TCU
threshold and the next moment the •Check the connectors
measured speed is zero •Check the speed sensor
•Cable/connector is defective and has bad •Check the sensor gap
contact
•Speed sensor has an internal defect
•Sensor gap has the wrong size

34 39 S.C. to battery voltage or O.C. at turbine OP mode : Substitute clutch control •Check the cable from TCU to
speed input If a failure is existing at output the sensor
TCU measures a voltage higher than 7.00V speed, •Check the connectors
at speed input pin TCU shifts to neutral •Check the speed sensor
•Cable is defective and is contacted to OP mode : Limp home
vehicle battery voltage
•Cable has no connection to TCU
•Speed sensor has an internal defect
•Connector pin is contacted to battery
voltage or has no contact

35 35 S.C. to ground at turbine speed input OP mode : Substitute clutch control •Check the cable from TCU to This fault is reset after power
TCU measures a voltage less than 0.45V at If a failure is existing at output the sensor up of TCU
speed input pin speed, •Check the connectors
•Cable/connector is defective and is TCU shifts to neutral •Check the speed sensor
contacted to vehicle ground OP mode : Limp home
•Speed sensor has an internal defect

36 43 Logical error at turbine speed input OP mode : Substitute clutch control •Check the cable from TCU to
TCU measures a turbine speed over a If a failure is existing at output the sensor
threshold and at the next moment the speed, •Check the connectors
measured speed is zero TCU shifts to neutral •Check the speed sensor
•Cable/connector is defective and has bad OP mode : Limp home •Check the sensor gap
contact
•Speed sensor has an internal defect
•Sensor gap has the wrong size

3-26
Fault code Int. code Meaning of the fault code
(Hex) (Dec) possible reason for fault detection Reaction of the TCU Possible steps to repair Remarks

37 40 S.C. to battery voltage or O.C. at internal OP mode : Substitute clutch control •Check the cable from TCU to
speed input the sensor
TCU measures a voltage higher than 7.00V •Check the connectors
at speed input pin •Check the speed sensor
•Cable is defective and is contacted to
vehicle battery voltage
•Cable has no connection to TCU
•Speed sensor has an internal defect
•Connector pin is contacted to battery
voltage or has no contact

38 36 S.C. to ground at turbine speed input OP mode : Substitute clutch control •Check the cable from TCU to
TCU measures a voltage less than 0.45V at the sensor
speed input pin •Check the connectors
•Cable/connector is defective and is •Check the speed sensor
contacted to vehicle ground
•Speed sensor has an internal defect

39 44 Logical error at internal speed input OP mode : Substitute clutch control •Check the cable from TCU to This fault is reset after power
TCU measures a internal speed over a the sensor up of TCU
threshold and at the next moment the •Check the connectors
measured speed is zero •Check the speed sensor
•Cable/connector is defective and has bad •Check the sensor gap
contact
•Speed sensor has an internal defect
•Sensor gap has the wrong size

3A 41 S.C. to battery voltage or O.C. at output Special mode for gear selection •Check the cable from TCU to
speed input OP mode : Substitute clutch control the sensor
TCU measures a voltage higher than 12.5V If a failure is existing at turbine •Check the connectors
at speed input pin speed, •Check the speed sensor
•Cable is defective and is contacted to TCU shifts to neutral
battery voltage OP mode : lamp home
•Cable has no connection to TCU
•Speed sensor has an internal defect
•Connector pin is contacted to battery
voltage or has no contact

3-27
Fault code Int. code Meaning of the fault code
(Hex) (Dec) possible reason for fault detection Reaction of the TCU Possible steps to repair Remarks

3B 37 S.C. to ground at output speed input Special mode for gear selection •Check the cable from TCU to
TCU measures a voltage less than 1.00V at OP mode : Substitute clutch control the sensor
speed input pin If a failure is existing at turbine •Check the connectors
•Cable/connector is defective and is speed, •Check the speed sensor
contacted to vehicle ground TCU shifts to neutral
•Speed sensor has an internal defect OP mode : lamp home

3C 45 Logical error at output speed input Special mode for gear selection •Check the cable from TCU to This fault is reset after power
TCU measures a turbine speed over a OP mode : Substitute clutch control the sensor up of TCU
threshold and at the next moment the If a failure is existing at turbine •Check the connectors
measured speed is zero speed, •Check the speed sensor
•Cable/connector is defective and has bad TCU shifts to neutral •Check the sensor gap
contact OP mode : lamp home
•Speed sensor has an internal defect
•Sensor gap has the wrong size

3D 71 Turbine speed zero doesn't fit to other - - Not used

speed signals

3E 72 Output speed zero doesn't fit to other Special mode for gear selection •Check the sensor signal of This fault is reset after power
speed signals OP mode : Substitute clutch control output speed sensor up of TCU
If transmission is not neutral and the shifting If a failure is existing at turbine •Check the sensor gap of
has finished, speed, output speed sensor
TCU measures output speed zero and TCU shifts to neutral •Check the cable from TCU to
turbine speed or internal speed not equal to OP mode : lamp home the sensor
zero.
•Speed sensor has an internal defect
•Sensor gap has the wrong size

3-28
Fault code Int. code Meaning of the fault code
(Hex) (Dec) possible reason for fault detection Reaction of the TCU Possible steps to repair Remarks

71 22 S.C. to battery voltage at clutch K1 TCU shifts to neutral •Check the cable from TCU to
The measured resistance value of the valve is OP mode : Limp home the gearbox
out of limit, the voltage at K1 valve is too high If failure at another clutch is •Check the connectors from
•Cable/connector is defective and has pending TCU to the gearbox
contact to battery voltage TCU shifts to neutral •Check the regulator resistance* * See Chapter (8)
•Cable/connector is defective and has OP mode : TCU shutdown •Check internal wire harness of
contact to another regulator output of the the gearbox
TCU
•Regulator has an internal defect

72 10 S.C. to ground at clutch K1 TCU shifts to neutral •Check the cable from TCU to
The measured resistance value of the valve is OP mode : Limp home the gearbox
out of limit, the voltage at K1 valve is too low If failure at another clutch is •Check the connectors from
•Cable/connector is defective and has pending gearbox to TCU
contact to vehicle ground TCU shifts to neutral •Check the regulator resistance* * See Chapter (8)
•Regulator has an internal defect OP mode : TCU shutdown •Check internal wire harness of
the gearbox

73 16 O.C. at clutch K1 TCU shifts to neutral •Check the cable from TCU to
The measured resistance value of the valve OP mode : Limp home the gearbox
is out of limit If failure at another clutch is •Check the connectors from
•Cable/connector is defective and has no pending gearbox to TCU
contact to TCU TCU shifts to neutral •Check the regulator resistance* * See Chapter (8)
•Regulator has an internal defect OP mode : TCU shutdown •Check internal wire harness of
the gearbox

74 23 S.C. to battery voltage at clutch K2 TCU shifts to neutral •Check the cable from TCU to
The measured resistance value of the valve OP mode : Limp home the gearbox
is out of limit, the voltage at K2 valve is too If failure at another clutch is •Check the connectors from
high pending gearbox to TCU
•Cable/connector is defective and has TCU shifts to neutral •Check the regulator resistance* * See Chapter (8)
contact to battery voltage OP mode : TCU shutdown •Check internal wire harness of
•Cable/connector is defective and has the gearbox
contact to another regulator output of the
TCU
•Regulator has an internal defect

3-29
Fault code Int. code Meaning of the fault code
(Hex) (Dec) possible reason for fault detection Reaction of the TCU Possible steps to repair Remarks

75 11 S.C. to ground at clutch K2 TCU shifts to neutral •Check the cable from TCU to
The measured resistance value of the valve is OP mode : Limp home the gearbox
out of limit, the voltage at K2 valve is too low If failure at another clutch is •Check the connectors from
•Cable/connector is defective and has pending gearbox to TCU
contact to vehicle ground TCU shifts to neutral •Check the regulator resistance* * See Chapter (8)
•Regulator has an internal defect OP mode : TCU shutdown •Check internal wire harness of
the gearbox

76 17 O.C. at clutch K2 TCU shifts to neutral •Check the cable from TCU to
The measured resistance value of the valve OP mode : Limp home the gearbox
is out of limit If failure at another clutch is •Check the connectors from
•Cable/connector is defective and has no pending gearbox to TCU
contact to TCU TCU shifts to neutral •Check the regulator resistance* * See Chapter (8)
•Regulator has an internal defect OP mode : TCU shutdown •Check internal wire harness of
the gearbox

77 24 S.C. to battery voltage at clutch K3 TCU shifts to neutral •Check the cable from TCU to
The measured resistance value of the valve OP mode : Limp home the gearbox
is out of limit, the voltage at K3 valve is too If failure at another clutch is •Check the connectors from
high pending gearbox to TCU
•Cable/connector is defective and has TCU shifts to neutral •Check the regulator resistance* * See Chapter (8)
contact to battery voltage OP mode : TCU shutdown •Check internal wire harness of
•Cable/connector is defective and has the gearbox
contact to another regulator output of the
TCU
•Regulator has an internal defect

78 12 S.C. to ground at clutch K3 TCU shifts to neutral •Check the cable from TCU to
The measured resistance value of the valve is OP mode : Limp home the gearbox
out of limit, the voltage at K3 valve is too low If failure at another clutch is •Check the connectors from
•Cable/connector is defective and has pending gearbox to TCU
contact to vehicle ground TCU shifts to neutral •Check the regulator resistance* * See Chapter (8)
•Regulator has an internal defect OP mode : TCU shutdown •Check internal wire harness of
the gearbox

3-30
Fault code Int. code Meaning of the fault code
(Hex) (Dec) possible reason for fault detection Reaction of the TCU Possible steps to repair Remarks

79 18 O.C. at clutch K2 TCU shifts to neutral •Check the cable from TCU to
The measured resistance value of the valve OP mode : Limp home the gearbox
is out of limit If failure at another clutch is •Check the connectors from
•Cable/connector is defective and has no pending gearbox to TCU
contact to TCU TCU shifts to neutral •Check the regulator resistance* * See Chapter (8)
•Regulator has an internal defect OP mode : TCU shutdown •Check internal wire harness of
the gearbox

7A 78 S.C. to battery voltage at converter clutch - -

7B 79 S.C. to ground at converter clutch - -

7C 80 O.C. at converter clutch - - Not used

7D 166 S.C. ground at engine derating device Engine derating will be on until •Check the cable from TCU to Not used
•Cable is defective and is contacted to TCU power down even if fault the engine derating device
vehicle ground vanishes(Loose connection) •Check the connectors from Not used
•Engine derating device has an internal defect OP mode : Normal engine derating device to TCU
•Connector pin is contacted to vehicle ground •Check the resistance* of engine * See Chapter (8)
derating device

7E 168 S.C. battery voltage at engine derating No reaction •Check the cable from TCU to
device OP mode : Normal the engine derating device
•Cable/connector is defective and is •Check the connectors from
contacted to battery voltage backup alarm device to TCU
•Engine derating device has an internal •Check the resistance* of * See Chapter (8)
defect backup alarm device

7F 167 O.C. at engine derating device No reaction •Check the cable from TCU to
TCU detected a wrong voltage at the output OP mode : Normal the engine derating device
pin, that looks like a O.C. for this output pin •Check the connectors from
•Cable is defective and has no connection engine derating device to TCU
to TCU •Check the resistance* of * See Chapter (8)
•Engine derating device has an internal engine derating device
defect
•Connector has no connection to TCU

3-31
Fault code Int. code Meaning of the fault code
(Hex) (Dec) possible reason for fault detection Reaction of the TCU Possible steps to repair Remarks

81 25 S.C. to battery voltage at clutch K4 TCU shifts to neutral •Check the cable from TCU to
The measured resistance value of the valve OP mode : Limp home the gearbox
is out of limit, the voltage at K4 valve is too If failure at another clutch is •Check the connectors from
high pending gearbox to TCU
•Cable/connector is defective and has TCU shifts to neutral •Check the regulator resistance* * See Chapter (8)
contact to battery voltage OP mode : TCU shutdown •Check internal wire harness of
•Cable/connector is defective and has the gearbox
contact to another regulator output of the
TCU
•Regulator has an internal defect

82 13 S.C. to ground at clutch K4 TCU shifts to neutral •Check the cable from TCU to
The measured resistance value of the valve is OP mode : Limp home the engine derating device
out of limit, the voltage at K4 valve is too low If failure at another clutch is •Check the connectors from
•Cable/connector is defective and has pending gearbox to TCU
contact to vehicle ground TCU shifts to neutral •Check the regulator resistance* * See Chapter (8)
•Regulator has an internal defect OP mode : TCU shutdown •Check internal wire harness of
the gearbox

83 19 O.C. at clutch K4 TCU shifts to neutral •Check the cable from TCU to
The measured resistance value of the valve OP mode : Limp home the gearbox
is out of limit If failure at another clutch is •Check the connectors from
•Cable/connector is defective and has pending gearbox to TCU
contact to TCU TCU shifts to neutral •Check the regulator resistance* * See Chapter (8)
•Regulator has an internal defect OP mode : TCU shutdown •Check internal wire harness of
the gearbox

84 26 S.C. to battery voltage at clutch K4 TCU shifts to neutral •Check the cable from TCU to
The measured resistance value of the valve OP mode : Limp home the gearbox
is out of limit, the voltage at K4 valve is too If failure at another clutch is •Check the connectors from
high pending gearbox to TCU
•Cable/connector is defective and has TCU shifts to neutral •Check the regulator resistance* * See Chapter (8)
contact to battery voltage OP mode : TCU shutdown •Check internal wire harness of
•Cable/connector is defective and has the gearbox
contact to another regulator output of the
TCU
•Regulator has an internal defect

3-32
Fault code Int. code Meaning of the fault code
(Hex) (Dec) possible reason for fault detection Reaction of the TCU Possible steps to repair Remarks

85 14 S.C. to ground at clutch KV TCU shifts to neutral •Check the cable from TCU to
The measured resistance value of the valve is OP mode : Limp home the gearbox
out of limit, the voltage at K4 valve is too low If failure at another clutch is •Check the connectors from
•Cable/connector is defective and has pending gearbox to TCU
contact to vehicle ground TCU shifts to neutral •Check the regulator resistance* * See Chapter (8)
•Regulator has an internal defect OP mode : TCU shutdown •Check internal wire harness of
the gearbox

86 20 O.C. at clutch KV TCU shifts to neutral •Check the cable from TCU to
The measured resistance value of the valve OP mode : Limp home the gearbox
is out of limit If failure at another clutch is •Check the connectors from
•Cable/connector is defective and has pending gearbox to TCU
contact to TCU TCU shifts to neutral •Check the regulator resistance* * See Chapter (8)
•Regulator has an internal defect OP mode : TCU shutdown •Check internal wire harness of
the gearbox

87 27 S.C. to battery voltage at clutch KR TCU shifts to neutral •Check the cable from TCU to
The measured resistance value of the valve OP mode : Limp home the gearbox
is out of limit, the voltage at KR valve is too high If failure at another clutch is •Check the connectors from
•Cable/connector is defective and has pending gearbox to TCU
contact to battery voltage TCU shifts to neutral •Check the regulator resistance* * See Chapter (8)
•Cable/connector is defective and has contact OP mode : TCU shutdown •Check internal wire harness of
to another regulator output of the TCU the gearbox
•Regulator has an internal defect
88 15 S.C. to ground at clutch KR TCU shifts to neutral •Check the cable from TCU to
The measured resistance value of the valve is OP mode : Limp home the gearbox
out of limit, the voltage at KR valve is too low If failure at another clutch is •Check the connectors from
•Cable/connector is defective and has pending gearbox to TCU
contact to vehicle ground TCU shifts to neutral •Check the regulator resistance* * See Chapter (8)
•Regulator has an internal defect OP mode : TCU shutdown •Check internal wire harness of
the gearbox

89 21 O.C. at clutch KR TCU shifts to neutral •Check the cable from TCU to
The measured resistance value of the valve OP mode : Limp home the gearbox
is out of limit If failure at another clutch is •Check the connectors from
•Cable/connector is defective and has no pending gearbox to TCU
contact to TCU TCU shifts to neutral •Check the regulator resistance* * See Chapter (8)
•Regulator has an internal defect OP mode : TCU shutdown •Check internal wire harness of
the gearbox

3-33
Fault code Int. code Meaning of the fault code
(Hex) (Dec) possible reason for fault detection Reaction of the TCU Possible steps to repair Remarks

91 1 S.C. to ground at relay reverse warning Backup alarm will be on until •Check the cable from TCU to
alarm TCU power down even if fault the backup alarm device
TCU detected a wrong voltage at the output vanishes(Loose connection) •Check the connectors from
pin, that looks like a S.C. to vehicle ground OP mode : Normal backup alarm device to TCU
•Cable is defective and is contact to vehicle •Check the resistance* of * See Chapter (8)
ground backup alarm device
•Backup alarm device has an internal defect
•Connector pin is contacted to vehicle ground

92 3 S.C. to battery voltage at relay reverse No reaction •Check the cable from TCU to
warning alarm OP mode : Normal the backup alarm device
TCU detected a wrong voltage at the output •Check the connectors from
pin, that looks like a S.C. to battery voltage backup alarm device to TCU
•Cable is defective and is contacted to •Check the resistance* of * See Chapter (8)
battery voltage backup alarm device
•Backup alarm device has an internal
defect
•Connector pin is contacted to battery
voltage

93 2 O.C. at relay reverse warning alarm No reaction •Check the cable from TCU to
TCU detected a wrong voltage at the output OP mode : Normal the backup alarm device
pin, that looks like a O.C. for this output pin •Check the connectors from
•Cable is defective and has no connection backup alarm device to TCU
to TCU •Check the resistance* of * See Chapter (8)
•Backup alarm device has an internal defect backup alarm device
•Connector has no connection to TCU

94 4 S.C. to ground at relay starter interlock No reaction •Check the cable from TCU to
TCU detected a wrong voltage at the output OP mode : Normal the stater interlock relay
pin, that looks like a S.C. to vehicle ground •Check the connectors from
•Cable is defective and is connection to starter interlock relay to TCU
vehicle ground •Check the resistance* of * See Chapter (8)
•Starter interlock relay has an internal defect starter interlock relay
•Connector pin is contacted to vehicle
ground

3-34
Fault code Int. code Meaning of the fault code
(Hex) (Dec) possible reason for fault detection Reaction of the TCU Possible steps to repair Remarks

95 6 S.C. to battery voltage at relay starter No reaction •Check the cable from TCU to
interlock OP mode : Normal the starter interlock relay
TCU detected a wrong voltage at the output •Check the connectors from
pin, that looks like a S.C. to battery voltage starter interlock relay to TCU
•Cable is defective and has no connection •Check the resistance* of * See Chapter (8)
to battery voltage starter interlock relay
•Starter interlock relay has an internal defect
•Connector pin is contacted to battery voltage

96 5 O.C. at relay starter interlock No reaction •Check the cable from TCU to
TCU detected a wrong voltage at the output OP mode : Normal the starter interlock relay
pin, that looks like a O.C. for this output pin •Check the connectors from
•Cable is defective and has no connection starter interlock relay to TCU
to TCU •Check the resistance* of * See Chapter (8)
•Starter interlock relay has an internal defect starter interlock relay
•Connector has no connection to TCU

97 7 S.C. to ground at park brake solenoid No reaction •Check the cable from TCU to
TCU detected a wrong voltage at the output OP mode : Normal the park brake solenoid
pin, that looks like a S.C. to vehicle ground •Check the connectors from
•Cable is defective and is connection to park brake solenoid to TCU
vehicle ground •Check the resistance* of park * See Chapter (8)
•Park brake solenoid has an internal defect brake solenoid
•Connector pin is contacted to vehicle
ground

98 9 S.C. to battery voltage at park brake No reaction •Check the cable from TCU to
solenoid Optional : (Some customers) the park brake solenoid
TCU detected a wrong voltage at the output TCU shifts to neutral caused by •Check the connectors from
pin, that looks like a S.C. to battery voltage park brake feed back park brake solenoid to TCU
•Cable is defective and is connection to OP mode : Normal •Check the resistance* of park * See Chapter (8)
battery voltage brake solenoid
•Park brake solenoid has an internal defect
•Connector pin is contacted to battery
voltage

3-35
Fault code Int. code Meaning of the fault code
(Hex) (Dec) possible reason for fault detection Reaction of the TCU Possible steps to repair Remarks

99 8 O.C. at park brake solenoid No reaction •Check the cable from TCU to
TCU detected a wrong voltage at the output Optional : Some customers the park brake solenoid
pin, that looks like a O.C. for this output pin TCU shifts to neutral caused by •Check the connectors from
•Cable is defective and has no connection park brake feed back park brake solenoid to TCU
to TCU OP mode : Normal •Check the resistance* of park * See Chapter (8)
•Park brake solenoid has an internal defect brake solenoid
•Connector has no connection to TCU

9A 66 S.C. to ground at converter lock up No reaction •Check the cable from TCU to
clutch solenoid OP mode : Normal the converter clutch solenoid
TCU detected a wrong voltage at the output •Check the connectors from
pin, that looks like a S.C. to vehicle ground converter clutch solenoid to
•Cable is defective and is contacted to TCU
vehicle ground •Check the resistance* of park * See Chapter (8)
•Converter clutch solenoid has an internal brake solenoid
defect
•Connector pin is contacted to vehicle ground

9B 67 O.C. at converter lock up clutch solenoid Converter clutch always open, •Check the cable from TCU to
TCU detected a wrong voltage at the output retarder not available the converter clutch solenoid
pin, that looks like a O.C. for this output pin OP mode : Normal •Check the connectors from
•Cable is defective and has no connection converter clutch solenoid to
to TCU TCU
•Converter clutch solenoid has an internal •Check the resistance* of park * See Chapter (8)
defect brake solenoid
•Connector has no connection to TCU

9C 68 S.C. to battery voltage at converter lock No reaction •Check the cable from TCU to
up clutch solenoid OP mode : Normal the converter clutch solenoid
TCU detected a wrong voltage at the output •Check the connectors from
pin, that looks like a S.C. to battery voltage converter clutch solenoid to
•Cable is defective and has no contacted TCU
to battery voltage •Check the resistance* of * See Chapter (8)
•Converter clutch solenoid has an internal converter clutch solenoid
defect
•Connector pin is contacted to battery voltage

3-36
Fault code Int. code Meaning of the fault code
(Hex) (Dec) possible reason for fault detection Reaction of the TCU Possible steps to repair Remarks

9D 81 S.C. to ground at retarder solenoid No reaction •Check the cable from TCU to
TCU detected a wrong voltage at the output OP mode : Normal the retarder solenoid
pin, that looks like a S.C. to vehicle ground •Check the connectors from
•Cable is defective and is contacted to retarder solenoid to TCU
vehicle ground •Check the resistance* of * See Chapter (8)
•Retarder solenoid has an internal defect retarder solenoid
•Connector pin is contacted to vehicle
ground

9E 82 O.C. at retarder solenoid No reaction •Check the cable from TCU to

TCU detected a wrong voltage at the output OP mode : Normal the retarder solenoid
pin, that looks like a O.C. for this output pin •Check the connectors from
•Cable is defective and has no connection retarder solenoid to TCU
to TCU •Check the resistance* of * See Chapter (8)
•Retarder solenoid has an internal defect retarder solenoid
•Connector has no connection to TCU

9F 83 S.C. to battery voltage at retarder No reaction •Check the cable from TCU to
solenoid OP mode : Normal the retarder solenoid
TCU detected a wrong voltage at the output •Check the connectors from
pin, that looks like a S.C. to battery voltage retarder solenoid to TCU
•Cable is defective and has no connection •Check the resistance* of * See Chapter (8)
to battery voltage retarder solenoid
•Retarder solenoid has an internal defect
•Connector pin is contacted to battery voltage

3-37
Fault code Int. code Meaning of the fault code
(Hex) (Dec) possible reason for fault detection Reaction of the TCU Possible steps to repair Remarks

A1 84 S.C. to ground at difflock or axle No reaction •Check the cable from TCU to
connection solenoid OP mode : Normal the difflock solenoid
TCU detected a wrong voltage at the output •Check the connectors from
pin, that looks like a S.C. to vehicle ground difflock solenoid to TCU
•Cable is defective and is contacted to •Check the resistance* of * See Chapter (8)
vehicle ground difflock solenoid
•Difflock solenoid has an internal defect
•Connector pin is contacted to vehicle ground

A2 85 S.C. to battery voltage at difflock or axle No reaction •Check the cable from TCU to
connection solenoid OP mode : Normal the difflock solenoid
TCU detected a wrong voltage at the output •Check the connectors from
pin, that looks like a S.C. to battery voltage difflock solenoid to TCU
•Cable is defective and has no connection •Check the resistance* of * See Chapter (8)
to battery voltage difflock solenoid
•Difflock solenoid has an internal defect
•Connector pin is contacted to battery voltage

A3 86 O.C. at difflock or axle connection solenoid No reaction •Check the cable from TCU to
TCU detected a wrong voltage at the output OP mode : Normal the difflock solenoid
pin, that looks like a O.C. for this output pin •Check the connectors from
•Cable is defective and has no connection difflock solenoid to TCU
to TCU •Check the resistance* of * See Chapter (8)
•Difflock solenoid has an internal defect difflock solenoid
•Connector has no connection to TCU

A4 96 S.C. to ground at warning signal output No reaction •Check the cable from TCU to
TCU detected a wrong voltage at the output OP mode : Normal the warning device
pin, that looks like a S.C. to vehicle ground •Check the connectors from
•Cable is defective and is contacted to warning device to TCU
vehicle ground •Check the resistance* of * See Chapter (8)
•Warning device has an internal defect warning device
•Connector pin is contacted to vehicle ground

3-38
Fault code Int. code Meaning of the fault code
(Hex) (Dec) possible reason for fault detection Reaction of the TCU Possible steps to repair Remarks

A5 97 O.C. voltage at warning signal output No reaction •Check the cable from TCU to
TCU detected a wrong voltage at the output OP mode : Normal the warning device
pin, that looks like a O.C. for this output pin •Check the connectors from
•Cable is defective and has no connection warning device to TCU
to TCU •Check the resistance* of * See Chapter (8)
•Warning device has an internal defect warning device
•Connector has no connection to TCU

A6 98 S.C. to battery voltage at warning signal No reaction •Check the cable from TCU to
output OP mode : Normal the warning device
TCU detected a wrong voltage at the output •Check the connectors from
pin, that looks like a S.C. to battery voltage warning device to TCU
•Cable is defective and has is contacted to •Check the resistance* of * See Chapter (8)
battery voltage warning device
•Warning device has an internal defect
•Connector pin is contacted to battery
voltage

3-39
Fault code Int. code Meaning of the fault code
(Hex) (Dec) possible reason for fault detection Reaction of the TCU Possible steps to repair Remarks

B1 60 Slippage at clutch K1 TCU shifts to neutral •Check pressure at clutch K1

TCU calculates a differential speed at closed OP mode : Limp home •Check main pressure in the
clutch K1. If this calculated value is out of If failure at another clutch is system
range, TCU interprets this as slipping clutch pending •Check sensor gap at internal
•Low pressure at clutch K1 TCU shifts to neutral speed sensor
•Low main pressure OP mode : TCU shutdown •Check sensor gap at output
•Wrong signal at internal speed sensor speed sensor
•Wrong signal at output speed sensor •Check signal at internal speed
•Wrong size of the sensor gap sensor
•Clutch is defective •Check signal at output speed
sensor
•Replace clutch

B2 61 Slippage at clutch K2 TCU shifts to neutral •Check pressure at clutch K2

TCU calculates a differential speed at closed OP mode : Limp home •Check main pressure in the
clutch K2. If this calculated value is out of If failure at another clutch is system
range, TCU interprets this as slipping clutch pending •Check sensor gap at internal
•Low pressure at clutch K2 TCU shifts to neutral speed sensor
•Low main pressure OP mode : TCU shutdown •Check sensor gap at output
•Wrong signal at internal speed sensor speed sensor
•Wrong signal at output speed sensor •Check signal at internal speed
•Wrong size of the sensor gap sensor
•Clutch is defective •Check signal at output speed
sensor
•Replace clutch

B3 62 Slippage at clutch K3 TCU shifts to neutral •Check pressure at clutch K3

TCU calculates a differential speed at closed OP mode : Limp home •Check main pressure in the
clutch K3. If this calculated value is out of If failure at another clutch is system
range, TCU interprets this as slipping clutch pending •Check sensor gap at internal
•Low pressure at clutch K3 TCU shifts to neutral speed sensor
•Low main pressure OP mode : TCU shutdown •Check sensor gap at output
•Wrong signal at internal speed sensor speed sensor
•Wrong signal at output speed sensor •Check signal at internal speed
•Wrong size of the sensor gap sensor
•Clutch is defective •Check signal at output speed
sensor
•Replace clutch

3-40
Fault code Int. code Meaning of the fault code
(Hex) (Dec) possible reason for fault detection Reaction of the TCU Possible steps to repair Remarks

B4 63 Slippage at clutch K4 TCU shifts to neutral •Check pressure at clutch K4

TCU calculates a differential speed at closed OP mode : Limp home •Check main pressure in the
clutch K4. If this calculated value is out of If failure at another clutch is system
range, TCU interprets this as slipping clutch pending •Check sensor gap at internal
•Low pressure at clutch K4 TCU shifts to neutral speed sensor
•Low main pressure OP mode : TCU shutdown •Check sensor gap at turbine
•Wrong signal at internal speed sensor speed sensor
•Wrong signal at turbine speed sensor •Check signal at internal speed
•Wrong size of the sensor gap sensor
•Clutch is defective •Check signal at turbine speed
sensor
•Replace clutch

B5 64 Slippage at clutch KV TCU shifts to neutral •Check pressure at clutch KV

TCU calculates a differential speed at closed OP mode : Limp home •Check main pressure in the
clutch KV. If this calculated value is out of If failure at another clutch is system
range, TCU interprets this as slipping clutch pending •Check sensor gap at internal
•Low pressure at clutch KV TCU shifts to neutral speed sensor
•Low main pressure OP mode : TCU shutdown •Check sensor gap at turbine
•Wrong signal at internal speed sensor speed sensor
•Wrong signal at turbine speed sensor •Check signal at internal speed
•Wrong size of the sensor gap sensor
•Clutch is defective •Check signal at turbine speed
sensor
•Replace clutch

B6 65 Slippage at clutch KR TCU shifts to neutral •Check pressure at clutch KR

TCU calculates a differential speed at closed OP mode : Limp home •Check main pressure in the
clutch KR. If this calculated value is out of If failure at another clutch is system
range, TCU interprets this as slipping clutch pending •Check sensor gap at internal
•Low pressure at clutch KR TCU shifts to neutral speed sensor
•Low main pressure OP mode : TCU shutdown •Check sensor gap at turbine
•Wrong signal at internal speed sensor speed sensor
•Wrong signal at turbine speed sensor •Check signal at internal speed
•Wrong size of the sensor gap sensor
•Clutch is defective •Check signal at turbine speed
sensor
•Replace clutch

3-41
Fault code Int. code Meaning of the fault code
(Hex) (Dec) possible reason for fault detection Reaction of the TCU Possible steps to repair Remarks

B7 87 Overtemp sump No reaction •Cool down machine

TCU measured a temperature in the oil OP mode : Normal •Check oil level
sump that is over the allowed threshold. •Check temperature sensor

B8 88 Overtemp retarder TCU disables retarder •Cool down machine

TCU measured a temperature in the retarder OP mode : Normal •Check oil level
oil that is over the allowed threshold •Check temperature sensor

B9 89 Overspend engine Retarder applies -

OP mode : Normal

BA 90 Differential pressure oil filter No reaction •Check oil filter

TCU measured a voltage at differential OP mode : Normal •Check wiring from TCU to
pressure switch out of the allowed range differential pressure switch
•Oil filter is polluted •Check differential pressure
•Cable/connector is broken or cable/ switch(Measure resistance)
connector is contacted to battery voltage
or vehicle ground
•Differential pressure switch is defective

BB 172 Slippage at converter lockup clutch •Check pressure at converter

TCU calculates a differential speed at closed lockup clutch
converter lockup clutch. If this calculated •Check main pressure in the
value is out of range, TCU interprets this as system
slipping clutch •Check sensor gap at engine
•Low pressure at converter lockup clutch speed sensor
•Low main pressure •Check sensor gap at turbine
•Wrong signal at engine speed sensor speed sensor
•Wrong signal at turbine speed sensor •Check signal at engine speed
•Wrong size of the sensor gap sensor
•Clutch is defective •Check signal at turbine speed
sensor
•Replace clutch

3-42
Fault code Int. code Meaning of the fault code
(Hex) (Dec) possible reason for fault detection Reaction of the TCU Possible steps to repair Remarks

BD 169 S.C. to ground at engine brake solenoid No reaction •Check the cable from TCU to
TCU detected a wrong voltage at the output OP mode : Normal engine brake solenoid
pin, that looks like a S.C. to vehicle ground •Check the connectors from
•Cable is defective and is contacted to engine brake solenoid to TCU
vehicle ground •Check the resistance* of engine * See Chapter (8)
•Engine brake solenoid has an internal brake solenoid
defect
•Connector pin is contacted to vehicle ground

BE 171 S.C. to battery voltage at engine brake No reaction •Check the cable from TCU to
TCU detected a wrong voltage at the output OP mode : Normal the engine brake solenoid
pin, that looks like a S.C. to battery voltage •Check the connectors from
•Cable is defective and is contacted to engine brake solenoid to TCU
battery voltage •Check the resistance* of engine * See Chapter (8)
•Engine brake solenoid has an internal defect brake solenoid
•Connector pin is contacted to battery voltage

BF 170 O.C. at engine brake No reaction •Check the cable from TCU to
TCU detected a wrong voltage at the output OP mode : Normal the engine brake solenoid
pin, that looks like a O.C. for this output pin •Check the connectors from
•Cable is defective and has no connection engine brake solenoid to TCU
to TCU •Check the resistance* of engine * See Chapter (8)
•Engine brake solenoid has an internal brake solenoid
defect
•Connector has no connection to TCU

3-43
Fault code Int. code Meaning of the fault code
(Hex) (Dec) possible reason for fault detection Reaction of the TCU Possible steps to repair Remarks

C3 91 Overtemp converter output No reaction •Cool down machine

TCU measured a oil temperature at the OP mode : Normal •Check oil level
converter output that is the allowed threshold •Check temperature sensor

C4 129 S.C. to ground at joystick status indicator No reaction •Check the cable from TCU to
TCU detected a wrong voltage at the output OP mode : Normal joystick status indicator
pin, that looks like a S.C. to vehicle ground •Check the connectors from
•Cable is defective and is contacted to joystick status indicator to TCU
vehicle ground •Check the resistance* of *See chapter (8)
•Joystick status indicator has an internal joystick status indicator
defect
•Connector pin is contacted to vehicle ground

C5 131 S.C. to battery voltage at joystick status No reaction •Check the cable from TCU to
indicator OP mode : Normal joystick status indicator
TCU detected a wrong voltage at the output •Check the connectors from
pin, that looks like a S.C. to battery voltage joystick status indicator to TCU
•Cable is defective and is contacted to •Check the resistance* of *See chapter (8)
battery voltage joystick status indicator
•Joystick status indicator has an internal
defect
•Connector pin is contacted to battery voltage

C6 130 O.C. at joystick status indicator No reaction •Check the cable from TCU to
TCU detected a wrong voltage at the output OP mode : Normal joystick status indicator
pin, that looks like a O.C. for this output pin •Check the connectors from
•Cable is defective and has no connection joystick status indicator to TCU
to TCU •Check the resistance* of *See chapter (8)
•Joystick status indicator has an internal joystick status indicator
defect
•Connector pin has no connection to TCU

3-44
Fault code Int. code Meaning of the fault code
(Hex) (Dec) possible reason for fault detection Reaction of the TCU Possible steps to repair Remarks

D1 54 S.C. to battery voltage at power supply See fault codes No.21 to 2C •Check cables and connectors Fault codes No.21 to No.2C
for sensors to sensors, which are supplied may be reaction of this fault
TCU measures more than 6V at the pin AU1 from AU1
(5V sensor supply) •Check the power supply at the
pin AU1(Should be appx. 5V)

D2 55 S.C. to ground at power supply for See fault codes No.21 to 2C •Check cables and connectors Fault codes No.21 to No.2C
sensors to sensors, which are supplied may be reaction of this fault
TCU measures less than 4V at the pin AU1 from AU1
(5V sensor supply) •Check the power supply at the
pin AU1(Should be appx. 5V)

D3 53 Low voltage at battery Shift to neutral •Check power supply battery

Measured voltage at power supply is lower OP mode : TCU shutdown •Check cables from batteries to
than 18V(24V device) TCU
•Check connectors from
batteries to TCU

D4 52 High voltage at battery Shift to neutral •Check power supply battery

Measured voltage at power supply is higher OP mode : TCU shutdown •Check cables from batteries to
than 32.5V(24V device) TCU
•Check connectors from
batteries to TCU

D5 57 Error at valve power supply VPS1 Shift to neutral •Check fuse

TCU switched on VPS1 and measured OP mode : TCU shutdown •Check cables from gearbox to
VPS1 is off or TCU switched off VPS1 and TCU
measured VPS1 is still on •Check connectors from
•Cable or connectors are defect and are gearbox to TCU
contacted to battery voltage •Replace TCU
•Cable or connectors are defect and are
contacted to vehicle ground
•Permanent power supply KL30 missing
•TCU has an internal defect

3-45
Fault code Int. code Meaning of the fault code
(Hex) (Dec) possible reason for fault detection Reaction of the TCU Possible steps to repair Remarks

D6 58 Error at valve power supply VPS2 Shift to neutral •Check fuse

TCU switched on VPS2 and measured OP mode : TCU shutdown •Check cables from gearbox to
VPS2 is off or TCU switched off VPS2 and TCU
measured VPS2 is still on •Check connectors from
•Cable or connectors are defect and are gearbox to TCU
contacted to battery voltage •Replace TCU
•Cable or connectors are defect and are
contacted to vehicle ground
•Permanent power supply KL30 missing
•TCU has an internal defect

3-46
Fault code Int. code Meaning of the fault code
(Hex) (Dec) possible reason for fault detection Reaction of the TCU Possible steps to repair Remarks

E1 91 S.C. battery voltage at speedometer - - Not used

output

E2 92 S.C. to ground or O.C at speedometer - - Not used

output

E3 S.C. to battery voltage at display output No reaction •Check the cable from TCU to
TCU sends data to the display and OP mode : Normal the display
measures always a high voltage level on the •Check the connectors at the
connector display
•Cable or connectors are defective and are •Change display
contacted to battery voltage
•Display has an internal defect

E4 S.C. to ground at display output No reaction •Check the cable from TCU to
TCU sends data to the display and OP mode : Normal the display
measures always a high voltage level on the •Check the connectors at the
connector display
•Cable or connectors are defective and are •Change display
contacted to battery voltage
•Display has an internal defect

E5 93, 104 Communication failure on DeviceNet Shift to neutral •Check Omron master
OP mode : TCU shutdown •Check wire of DeviceNet-Bus
•Check cable to Omron master

E5 104 DISPID1 timeout TCU select parameter set with •Check display controller
Timeout of CAN-massage DISPID1 from ID0 •Check wire of CAN-Bus
display controller OP mode : Limp home •Check cable display controller
•Interference on CAN-Bus
•CAN wire/connector is defective
•Can wire/connector is defective and has
contact to vehicle ground or battery voltage

3-47
Fault code Int. code Meaning of the fault code
(Hex) (Dec) possible reason for fault detection Reaction of the TCU Possible steps to repair Remarks

F1 51 General EEPROM fault No reaction •Replace TCU Often shown together with
TCU can't read non volatile memory OP mode : Normal fault code F2
•TCU is defective

F2 56 Configuration lost Transmission stay neutral •Reprogram the correct

TCU has lost the correct configuration and OP mode : TCU shutdown configuration for the vehicle
can't control the transmission (e.g. with cluster controller,...)
•Interference during saving data on non
volatile memory
•TCU is brand new or from another vehicle

F3 59 Application error Transmission stay neutral •Replace TCU This fault occurs only if an test
Something of this application is wrong OP mode : TCU shutdown engineer did something wrong
in the application of the vehicle

F5 173 Clutch failure Transmission stay neutral •Check clutch TCU shows also the affected
AEB was not able to adjust clutch filling OP mode : TCU shutdown clutch on the display
parameters
•One of the AEB-Values is out of limit

F6 174 Clutch adjustment data lost No reaction, •Execute AEB

TCU was not able to read correct clutch Default values : 0 for AEB
adjustment parameters Offsets used
•Interference during saving data on non OP mode : Normal
volatile memory
•TCU is brand new

3-48
(8) Measuring of resistance at actuator/sensor and cable
① Actuator

2 G 76043PT19

Open circuit R12 = R1G = R2G = ∞

Short cut to ground R12 = R; R1G = 0, R2G = R or R1G = R, R2G = 0
(For S.C. to ground, G is connected to vehicle ground)
Short cut to battery R12 = R; R1G = 0, R2G = R or R1G = R, R2G = 0
(For S.C. to battery, G is connected to battery voltage)

② Cable

UBat

P(Power supply)
TCU
1 Actuator/
2 Sensor

C(Chassis)

Ground 76043PT20

Open circuit R12 = R1P = R1C = R2P = R2C= ∞

Short cut to ground R12 = 0; R1C = R2C = 0, R1P = R2P = ∞
Short cut to battery R12 = 0; R1C = R2C = 0, R1P = R2P = 0

3 - 49
7) ELECTRIC CONTROL UNIT
(1) Complete system
2
1

12
10
5 4
3 9
7

A
13

2
6

11

14

7407PT03

1 Control unit(EST-37A)
2 Kickdown switch
3 Clutch cut off switch
4 Auto select switch
5 LCD
6 Gear selector(DW-3) with integrated kickdown switch
7 Supply-system connection
8 Transmission
9 Cable to inductive transmitter - speed central gear train
10 Cable to inductive transmitter - speed turbine
11 Cable to inductive transmitter - speed engine
12 Cable to speed sensor output and speedometer
13 Cable to plug connection on the electro - hydraulic control unit
14 Brake pressure sensor/load sensor
(2) Description of the basic functions
The powershift-reversing transmissions will be equipped with the electronic transmission control
unit(EST-37A), developed for them.
The system is processing the wishes of the driver according to the following criteria.
・Speed definition as a function of gear selector position, driving speed and load level.

3 - 50
 ・Protection against operating errors, as far as possible and practical.
・Protection against overspeeds(On the basis of engine and turbine speed).
・Reversing-automatic system(Driving speed-dependent).
・Pressure cut off(Disconnecting of the drive train for maximum power on the power take-off).
・Switch for manual or automatic operation.
・Reversing function button, respectively kickdown function.

(3) Gearshifts
The control unit(EST-37A) is shifts the required speeds fully-automatically under consideration of
the following criteria.
・Gear selector position
・Driving speed
・Load level
At the same time, the following speeds are picked up by the control unit(EST-37A).
・n Engine
・n Turbine
・n Central gear train
・n Output

- Neutral position
Neutral position is selected through the gear selector.
After the ignition is turned on, the electronics remains in the waiting state; By the position neutral
of the gear selector, respectively by pressing on the key neutral, the control unit(EST-37A)
becomes ready for operation.
Now, a speed can be engaged.
- Speed engagement
In principle, the speed, adapted to the driving speed(At standing, or rolling machine), will be
engaged. The engagement is realized in dependence on load and rotational speed.
- Upshifting under load
Upshifting under load will be then realized if the machine can still accelerate by it.
- Downshifting under load
Downshifting under load will be realized if more traction force is needed.
- Upshifting in coasting condition
In the coasting condition, the upshifting will be suppressed if the speed of the machine on a slope
shall not be further increased.
- Downshifting in coasting condition
Downshiftings in the coasting condition will be realized if the machine shall be retarded.
- Reversing
At speeds below the reversing limit, direct reversing can be carried out at any time in the speeds
1F 1R and 2F 2R(As a rule, this is the maximum driving speed of the 2nd speed).

3 - 51
 Reversings in the speeds 3 and 4 are realized dependent on the driving speed.
- Above the programmed reversing limit, the machine is braked down by downshifts of the
electronic control unit(EST-37A) to the permitted driving speed, and only then, the reversing into
the correspondingly preselected speed will be carried out.
- Below the permitted driving speed, the reversing is carried out immediately.
(4) Specific kickdown function
By means of the kickdown-button, integrated in the gear selector, it is at any time possible to
select in the speeds 2F and 2R(i.e. position 2 of the gear selector, at automatic mode also in the
2nd speed of the automatic range) the 1st speed by a short touch. This kickdown state can be
cancelled by :
1. Pressing the kickdown-button again
2. Realization of a reversal operation
3. Change of the gear selector position by the following modification
Gear selector(DW-3) - (Rotation) of the driving position 1...4.
The kickdown function will be always terminated by shifting to neutral.
(5) Clutch cut off
Especially at wheel loaders, the clutch cut off can be activated through a switch signal. It is
interrupting the power flow in the transmission as long as this signal is active. Besides, this
function can be used for the transmission-neutral shifting at applied hand brake or as emergency-
stop(In this case, a restarting is only possible through the gear selector-neutral position).

3 - 52
5. AXLE
1) OPERATION
・ The power from the engine passes through torque converter, transmission and drive shafts, and is
then sent to the front and rear axles.
・ Inside the axles, the power passes from the bevel pinion to the bevel gear and is sent at right
angles. At the same time, the speed is reduced and passes through the both differentials to the
axle shafts. The power of the axle shafts is further reduced by planetary-gear-type final drives and
is sent to the wheels.
(1) Front axle

73033AX01A

1 Final drive 2 Differential 3 Axle

(2) Rear axle

73033AX01B

1 Final drive 2 Differential 3 Axle

3 - 53
2) SECTION OF FRONT AXLE DIFFERENTIAL(LIMITED SLIP)
(1) Structure

1 2 3

6 5
7803ASPT15

1 Axle shaft 4 Clutch

2 Case 5 Side gear
3 Pinion gear 6 Pinion shaft

2) Operation

No driving When driving

N F

Ramp

Pinion shaft F
7803ASPT16

When the differential case is rotated, pinion shaft is moved up on the ramp by the resistance force of
tires as the figure, and then force P is generated. This force P becomes the engaging force of clutch.
① When travelling straight(equal resistance from road surface to left and right tires). Under this
condition, both clutch are engaged and the left and right side gears are driveb wutg tge sane
firce.
② When travelling on soft ground(Resistance from road surface to right tire is smaller). At rotating
speed of right tire becomes faster than left due to the smaller resistance of right tive, right clutch
is engaged and torque of faster rotating right axle shaft is added to left axle shaft through
diffenenting gear case.

3 - 54
3) SECTION OF REAR AXLE DIFFERENTIAL(CONVENTIONAL)

2 1

76043PT19

1 Bevel pinion 3 Side gear(Differential) 5 Bevel gear

2 Shaft 4 Sun gear

3 - 55
4) DIFFERENTIAL
(1) Description 3
When the machine makes a turn, the 2 4
outside wheel must rotate faster than the
inside wheel. A differential is a device
which continuously transmits power to the
right and left wheels while allowing them
to turn a different speeds, during a turn.
The power from the drive shaft passes
through bevel pinion(1) and is transmitted
to the bevel gear(2). The bevel gear
changes the direction of the motive force
by 90 degree, and at the same time
1
reduces the speed.
It then transmits the motive force through
the differential(3) to the axle gear shaft(4). (740-3A) 3-26(1)

(2) When driving straight forward

Pinion gear
When the machine is being driven straight
Side gear Side gear
forward and the right and left wheels are
rotating at the same speed, so the pinion Axle gear shaft
gear inside the differential assembly do not
rotate. The motive force of the carrier is
send through the pinion gear and the side
gear, therefore the power is equally Carrier
transmitted to the left and right axle gear Pinion gear
shaft.
(740-3A) 3-26(2)

(3) When turning

Swing
When turning, the rotating speed of the
Pinion gear
left and right wheels is different, so the
Side gear Side gear
pinion gear and side gear inside the
differential assembly rotate in accordance
with the difference between the rotating
speed of the left and right wheels.
The power of the carrier is then
transmitted to the axle gear shafts. Carrier

Pinion gear Ring gear

(740-3A) 3-26(3)

3 - 56
5) TORQUE PROPORTIONING DIFFERENTIAL
(1) Function
① Because of the nature of their work, 4-
wheel-drive loaders have to work in
places where the road surface is bad.
In such places, if the tires slip, the ability
to work as a loader is reduced, and also
the life of the tire is reduced.
The torque proportioning differential is
installed to overcome this problem.
In structure it resembles the differential of
an automobile, but the differential pinion
gear has an odd number of teeth.
Because of the difference in the
resistance from the road surface, the
position of meshing of the pinion gear
and side gear changes, and this changes
the traction of the left and right tires.

(2) Operation
Spider rotating
① When traveling straight(Equal direction
resistance from road surface to left and
right tires)
Under this condition, the distances
involving the engaging points between
FL FR
right and left side gears and pinion-a and Engaging a b
Engaging
point point
b-are equal and the pinion is balanced as
FL×a=FR×b. Thus, FL=FR, and the
right and left side gears are driven with
Left side gear Pinion Right side gear
the same force.
(740-3A) 3-27

3 - 57
② When traveling on soft ground
(Resistance from road surface to left and
right tires is different)
If the road resistance to the left wheel is
Spider rotating
smaller, the left side gear tends to rotate direction
forward, and this rotation changes the
engaging points between the side gears
and pinion. As a result, the distances
involving the engaging points becomes FL
Small road FR
Large road
a>b. The pinion now is balanced as FL resistance a b resistance
×a=FR×b, where FL>FR. The right Engaging Engaging
side gear is driven with a greater force point point
than the left side gear. The torque can
Left side gear Right side gear
be increased by up to about 30% for Pinion
either side gear.
The pinion therefore does not run idle
and driving power is transmitted to both
side gears until the difference between
road resistance to the right and left
(740-3A) 3-27
wheels reaches about 30%.

3 - 58
6) FINAL DRIVE(Front & rear)

7403APT03

1 Axle shaft 2 Ring gear

3 Planetary gear

(1) To gain a large drive force, the final drive uses a planetary gear system to reduce the speed and
send drive force to the tires.
(2) The power transmitted from the differential through axle shaft(1) is transmitted to planetary
gear(2). The planetary gear rotates around the inside of a fixed ring gear(3) and in this way
transmits rotation at a reduced speed to the planetary carrier.
This power is then sent to the wheels which are installed to the planetary carriers.

3 - 59
6. TIRE AND WHEEL

1
(740-3A) 3-30

1 Wheel rim 3 O-ring 5 Side ring

2 Tire 4 Lock ring 6 Valve assembly

1) The tire acts to absorb the shock from the ground surface to the machine, and at the same time
they must rotate in contact with the ground to gain the power which drives the machine.
2) Various types of tires are available to suit the purpose. Therefore it is very important to select the
correct tires for the type of work and bucket capacity.

3 - 60