62-1

80ZV Function & Structure Electrical Group

80ZV Function & Structure

Electrical Group

How to Use Electrical Wiring Diagram ..................................62-2

Electrical Cable Color Codes ................................................62-3
Electrical Circuit Symbols......................................................62-4
Sensor Mount ........................................................................62-5
Fuse ......................................................................................62-6
Engine Start Circuit..............................................................62-10
Power Generating/Charging Circuit.....................................62-20
Transmission Control Circuit and Monitor Circuit ................62-21
Instrument Panel and Switch...............................................62-38
Electrical Detent Circuit .......................................................62-42
Diode ...................................................................................62-45
Diagnostic System...............................................................62-49
62-2
80ZV Function & Structure Electrical Group
How to Use Electrical Wiring Diagram

How to Use Electrical Wiring Diagram

Example

10 6 5 1
10 9 8 7 6 5 4 3 2 1
20 19 18 17 16 15 14 13 12 11
21
40 39 32 31
40 36 35 31

WIDTH LAMP RIDE CONTROL NEUTRAL BACK LAMP HORN RELAY CONTROLLER
RELAY RELAY RELAY RELAY FAULT RELAY

A520 RB RB LgSb YV RL SbP RL LB GW GL B LgW

C201 B611 H133 E214 H610 E220 H128 E219 H127 B501 E218
H129
R R Br Lg G L R Lg G G LgW L
D114 D114 D112 D103 D102 D002 D111 D103 D107 D107 A405 D001

2 1 2 1 2 1 2 1 2 1 2 1
(BLACK) (BLACK) (BLACK) (BLACK) (BLACK) (BLUE)

F5 F0 F6 F7 F8 F9

(1)
(2)
H1

10 6 5 1

D507 A306 F306 A905 A503 D112 E802 E803

OR RO RW RLg YB Br GL GO

C206 A302 F303 E312 E523 G302 E804

PB RBr RY WO SbY BrB WY

C205 F504 F704 F804 E109 G402 A105 E522

PL RB RL GW W BrW WP BrL

E501 C801 A005 B304 E520 E108 F004 E601

WL RG RGy LgG LgL W LgSb BrR
40 36 35 31

(3) 95ZV62001

The address method is used for electrical wiring dia- Example 3

grams. For this method, a symbol is attached to each Checking the other connector terminal where F704 RL
connector and connector terminal in order to easily (item (3)) is connected:
locate the other terminal where the other end of the
cable is connected. 1. F704
Shows that the terminal is connected to the 4th ter-
Example 1 minal of the F7 connector.
Symbol under (or above) connector, such as F6: Check the description in the 4th terminal of the F7
Shows the address of the connector. connector (F704), it shows that the F704 terminal is
connected to H128. This means that the 4th termi-
Example 2 nal of the F7 connector is connected to the 28th ter-
Symbol at the multi-terminal connector, such as 1 and minal of the H1 connector.
10: 2. RL
Shows the terminal number and the numbering direc- Shows the color of the wire "RL" represents that the
tion. insulation color is red, and "L" represents a blue
stripe is on the red insulation.
 62-3
80ZV Function & Structure Electrical Group
Electrical Cable Color Codes

Electrical Cable Color Codes

Color of
stripe Y G Sb Br L W R B O Lg P Gy V
Color of (yellow) (green) (sky blue) (brown) (blue) (white) (red) (black) (orange) (light green) (pink) (grey) (violet)
insulation

Y (yellow) Y YG YSb YBr YL YW YR YB YO YGy YV

G (green) GY G GL GW GR GB GO

Sb (sky blue) SbY SbG Sb SbW SbR SbO SbLg SbP

Br (brown) BrY BrG Br BrL BrW BrR BrB

L (blue) LY LG LBr L LW LR LB LO LLg LP

W (white) WY WG WL W WR WB WO WP WV

R (red) RY RG RBr RL RW R RB RO RLg RGy

B (black) BY BG BL BW BR B BO BLg BP BV

O (orange) OY OG OSb OL OW OR OB O

Lg (light green) LgY LgG LgSb LgBr LgL LgW LgR LgB Lg

P (pink) PG PL PW PB P

Gy (grey) GyY GyG GyL GyW GyR GyB GyO Gy

V (violet) V

Insulation color

Stripe color

70ZV62001
62-4
80ZV Function & Structure Electrical Group
Electrical Circuit Symbols

Electrical Circuit Symbols

Name Symbol Name Symbol

Direct current Motor M

Alternating current Equipment

Conductor (General) Fuses

Branching connection Lamp

Conductors (Connected) Rectifiers

Conductors
Mechanical coupling
(Not connected)

Relay contact
Terminal
("a" contact)

Relay contact
Ground
("b" contact)

Resistance or Resistor Switch

Variable resistance or Variable Pressure switch or

resistor Temperature switch

Inductance or Electromagnetic Negative -positive-

coil negative (NPN) transistor

Positive -negative-
Battery or Direct voltage source
positive (PNP) transistor
 62-5
80ZV Function & Structure Electrical Group
Sensor Mount

Sensor Mount

3 2 4 5 6

1
K80ZV62001

1. Machine speed sensor

2. T/C oil temperature sensor
3. T/C oil temperature switch
4. E/G water temperature switch
5. E/G water temperature sensor
6. E/G oil pressure switch
7. Tachometer sensor
8. Fuel level sensor
9. Air cleaner clogging sensor
62-6
80ZV Function & Structure Electrical Group
Fuse

Fuse
The following fuses are provided to protect electrical cir- Fuse box location
cuits.
(S/N 80C4-5001~5270)
Fusible link 2
70 A x 2, 30 A x 1

Fuse box
15 fuses x 2 (for chassis and cab)
3 A x 1 (for fuel solenoid relay)
1

CAUTION
Possible burn hazard. Before replacing a fuse, be
sure to turn off the starter switch. S97ZVOM0086

IMPORTANT (S/N 80C4-5271~)

Replace a fuse with the same capacity.

If a fuse blows immediately after replacement, the
electric system is defective. Locate the defective part,
and then repair it.

1 2 S80ZV8214

(S/N 80C4-5001~)

S65ZVOM3131

1. For chassis
2. For cab
3. For fuel solenoid relay

(For installation positions, refer to "Electrical Equipment

Layout" too.)
 62-7
80ZV Function & Structure Electrical Group
Fuse

Fuse box 3. For fuel solenoid relay

Fuse
Fuse No. Protective circuit
1. For chassis capacity (A)
— 3A Fuel solenoid relay
Fuse
Fuse No. capacity Protective circuit
(A)
1 20A Lighting head light
2 15A Rear work light 20A
Boom kickout
3 10A
Bucket leveler
Back lamp Spare
4 15A Stop lamp
Turn signal
Parking brake
5 10A 15A
Controller (machine)
6 15A Front work light
Spare
7 10A Air suspension seat (option)
8 15A Spare 10A
9 15A Spare
4-way flasher
Horn Spare
10 15A
Room lamp
Radio backup
11 10A Fuel solenoid valve 5A
12 15A Preheat
Buzzer Spare
13 5A
Monitor (controller)
14 5A Neutral relay
15 5A Battery relay

2. For cab

Fuse
Fuse No. capacity Protective circuit
(A)
16 5A Radio
17 5A Spare 20A
18 5A Rear wiper
Spare
19 10A Front wiper
20 10A Spare 15A
DC-DC converter (cigar lighter)
21 15A
(S/N 5172~) Spare
22 3A Spare
23 10A Spare 10A
24 10A Spare
Spare
25 20A Air conditioner (option)
26 5A Spare 5A
27 5A Spare
Spare
28 10A Spare
29 20A Air conditioner (option)
30 20A Spare
62-8
80ZV Function & Structure Electrical Group
Fuse

Fusible link 30A

(001)
[W5]
12V 12V

(003) W
(002) W5
BATTERY
(008) (018)
R1 BR F15 WR WP
B AC
BW R2 C 5A [WV]
(026) 1.25 (010)
(013) WR
Fusible link G1.25 (006) BATTERY

15A
F12

F14
5A
RELAY
BW G1.25
(027) (037) (014)
W1.25 STARTER

3A
(1)

70A
(038)
W1.25 BC

MAGNETIC
(011) (012)
[R 5] S/W BW5

RL1.25(015) [WG] (016)

NR
(108) (016)
(Lg) (WG) VOLTAGE RELAY
F13 (019)
CHARGE LAMP WL
CONTROLLER
R5X6 WL1.25
(017)
(020~025)
(2) ALTERNATOR
20 R
70A B I
1.25 E
WR
S80ZVOM3288 (007) 20
(108)
F13 (Lg)
MONITOR LAMP
WB1.25 5A (034) FUEL FUEL VALVE
(033) F11 WB
SOLENOID
10A (036) RELAY
Fusible link R 2
(035)
2 BW
Cover
Fuse W1.25
element (038)

(027)
HEATER
BW RELAY

15 15
AIR
(BG) HEATER
(028)

PREHEAT
B ACC’
LAMP E
Fusible link location (S/N 5001~5333) 80ZV62010

(001) 12V 12V

[W5]
30A
Box for fusible link Fusible link (003) W
BATTERY
70ZV62010 (002) W5
(008) (018)
R1 BR F15 WR WP
B AC
BW R2 C 5A [WV]
(026) 1.25 (010)
(013) WR
The fusible link is located in the box as shown in the G1.25 (006) BATTERY
15A
F12

F14
5A

RELAY
above figures. BW
(027)
G1.25
(014)
STARTER
(037)
(1)
70A

W1.25
3A

BC
If excessive current flows through the starter switch or (038)
W1.25
MAGNETIC
the electric line downstream of the starter switch due to (011) S/W
5
(012)
5
[R ] BW
short-circuit, the fuse element will be blown to protect RL
1.25
(015) [WG] (016)

the circuit. The condition of the fuse element can be NR

(108) (016)

seen through the transparent cover. F13

(Lg) (WG) VOLTAGE
RELAY
CHARGE LAMP
Determine the cause before replacing the fusible link. R5X6
(020~025)
WL (019)
CONTROLLER
WL
ALTERNATOR
(2) (017)

20 L R
For replacement of a fusible link, remove 2 bolts and 1.25
WR
70A B E
20
pull it up. (007)
F13
(108)
(Lg) MONITOR
WB1.25 5A (034) FUEL VALVE LAMP
(033) F11 WB
10A FUEL
SOLENOID
(036) RELAY (035)
R2 BW2

W1.25
(038) HEATER
(027)
BW
RELAY

15 15
AIR
(BG) HEATER
(028)
B ACC’
PREHEAT LAMP E
Fusible link location (S/N 5334~) K80ZV62002
 62-9
80ZV Function & Structure Electrical Group
Fuse

Problems caused by fused fusible link

Fuse Problem (symptom)

damaged During engine operation During engine stop
- Engine will stop auto-
- All the electrical circuit
matically.
will not function.
30A - All the power for all
- Engine can not be
electrical circuit will be
started
OFF.
- Horn [and optional
flasher] will operate.
- All the others will not
operate and the
- The same conditions
machine can not be
70A as “During engine oper-
operated.
(1) ation” but engine can
- Engine will not stop
be started and stopped.
automatically but can
be stopped by turning
the starter switch to
“OFF”.
- The machine can be
operated but the batter- - The same conditions
70A
ies can not be charged as “During engine oper-
(2)
and the batteries will be ation”.
discharged soon.
62-10
80ZV Function & Structure Electrical Group
Engine Start Circuit

Engine Start Circuit

Engine start circuit diagram

Starter switch
Terminal
B BR AC R2 C
Off
Fusible link
On Battery (24 V)
Start 30A
3A
Fuel solenoid

F11 10A
F15
5A Battery relay
70A Fuel solenoid relay
T/M controller
Diode unit
Starter motor
From alternator
Shift lever F/R position

F14
N +24V 5A Magnetic S/W
R F
Shift
lever 3
LED 4
(Indication: N)
1 2

Neutral relay
Voltage relay

+24V Neutral
(F5) current
alternator
* When shift lever is in F/R position: OFF
When shift lever is in N position: ON

65ZV62014
 62-11
80ZV Function & Structure Electrical Group
Engine Start Circuit

Neutral starter
To prevent the machine from unexpected movement at
engine start up, the machine is so designed that the
engine can start only while the shift lever is in the neu-
tral (N) position.

Shift lever neutral (N) position

When the starter switch is turned to the ON position

while the shift lever is located in the N position, the coil
actuation circuit of the neutral relay is connected to the
ground of the controller unit and the contact of the neu-
tral relay is switched over to ON.

When the starter switch is turned to the START position,

the start command current flows from the starter switch
terminal C to the neutral relay, the magnetic switch and
the voltage relay. As a result, the magnetic switch turns
ON, the starting current flows in the starter motor, and
the engine starts.

At this time, the LED (indication: N) of the output circuit

is lit.

Shift lever forward/reverse (F/R) position

While the shift lever is located in the F or R position, the

power is not supplied to the neutral relay coil, and the
main contact is OFF. As a result, the starting current
from the starter switch terminal C does not flow in the
magnetic switch, and the engine does not start.
At this time, the LED (indication: N) of the output circuit
is off.
62-12
80ZV Function & Structure Electrical Group
Engine Start Circuit

Starter switch

35º OFF 30º

ON
Preheat
35º
Start
B
C
C
AC
BR

R1

R2

W3
W5 Connection table
B BR ACC R1 R2 C
BW R1 BR WR x 2
Preheat
B AC WB x 2
OFF
BG
BG R2 C G
ON

Start
To fuel solenoid relay
To fuel solenoid

To battery relay

To neutral relay
To heater relay

1.25
BW WR WR G W5
From battery

BG WB WB W3

K90ZV62003

OFF
Enables insertion and removal of the starter key.
All the electrical circuits (except the horn and optional
hazard flasher) will be turned off.

ON
Supplies power to the charge, lamp, and monitor cir-
cuits.

Start
Starter switch Starts the engine.

K90ZV62004 Preheat
Preheats the intake air to ensure smooth starting in cold
weather.
 62-13
80ZV Function & Structure Electrical Group
Engine Start Circuit

Accelerator pedal

1
25

2 11
10

10
12
9 13
2
7
3
8
3
8
4

4
6

Stroke
5 44.5 6 5
(1.8 in)

1. Accelerator pedal
2. Rod
3. Lever
4. Plate (mm)
(in)
5. Cable support 44.5
6. Clevis 40 (1.8)
(1.6)
7. U bolt
30
8. Nut Lever (1.2)
9. Return spring stroke 20
10. Bellows (0.8)
11. Adjusting bolt 10
(0.4)
12. Lock nut
13. Bearing 0 10 20
Pedal angle

65ZV22003
62-14
80ZV Function & Structure Electrical Group
Engine Start Circuit

Fuel control

(S/N 5001~5050)
158 mm (6.2 in)

Accelerator pedal Control cable

Reference
dimension At low idle

Engine

(S/N 5051~)
in)
m (6.1

Accelerator pedal Control cable

Reference
1 55 m

dimension At low idle

Engine

(S/N 5001~5050)
Ball joint

192 mm
17 mm (0.7 in
) (7.6 in)
Rotational (cable screw de
pth) At low idle
center
(S/N 5051~)
C

Carefully tighten the nut to

147 mm (5.8 in prevent the control cable
)
At low idle Ball joint from distortion or damage.
Stroke 180 mm Torque value
(7.1 in) 54 N-m (5.5 kgf-m)(39 lb-ft)
At low idle

Detail of A Detail of B Detail of C

K80ZV62007
 62-15
80ZV Function & Structure Electrical Group
Engine Start Circuit

Ball joint installation Adjusting accelerator pedal

(S/N 5001~5050)
Standard screw depth: 10 mm (0.4 in)
Min.: 5 mm (0.2 in) Throttle Idle
lever

Full
stroke

Control cable 16mm

Ball joint 1
(0.6 in)
Reference dimension
(S/N 5051~) 2
Standard screw depth: 10 mm (0.4 in) Throttle
Min.: 5 mm (0.2 in) lever

65ZV22005

Press the accelerator pedal at full stroke, and check that

the accelerator pedal comes in contact with the top of
16mm adjusting bolt (1). If not, adjust the accelerator pedal
Control cable
(0.6 in) Ball joint and lock it with lock nut (2).
Reference dimension

Ball joint installation procedure Lock nut (2): 9 N-m (0.9 kgf-m) (6.5 lb-ft)
K80ZV62006
62-16
80ZV Function & Structure Electrical Group
Engine Start Circuit

Fuel solenoid valve

Boot
Plunger

Rod end Boot Connector*

*Note: The connector must be modified to accept the three pin "AMP" type connector. The mounting bracket is slightly different than shown.

K80ZV62018

Fuel solenoid valve specification

(at 68 ºF)
Volt (V) DC 24 V
Pull current (A) 39.0
Hold current (A) 0.46
Pull force N (lb) 89 (20)
Hold force N (lb) 178 (40)
Coil PULL ( ) 0.62
Resistance HOLD ( ) 51.95
Connector
Rod end
Connector wire color K80ZV62005

A R HOLD
When the starter switch is turned to “ON”, the fuel sole-
B W PULL
noid relay is turned to “ON” and electric current is sup-
C B Ground
plied to the fuel solenoid valve.
The fuel solenoid valve is energized and moves the rod
to open the fuel supply circuit in the fuel pump.
When the starter switch is turned to “OFF”, no electric
current is supplied to both fuel solenoid relay and fuel
solenoid valve and then the fuel supply circuit is closed.

Fuel solenoid relay

R BW

W B

Circuit diagram

65ZV62019
 62-17
80ZV Function & Structure Electrical Group
Engine Start Circuit

Battery relay Alternator I (R) terminal wire

Terminals for coil Moving contact

energizing current 12V 12V

(4 mm) Main contacts 30A

BATTERY (1)
R1 BR F15 (2) (3)
B AC
R2 C 5A
(013) (2) (3)...Diode unit
BR BATTERY
RELAY Suppression diode
F13
B
Terminals for F11 Charge circuit
Neutral relay
main current From alternator
Coil for energizing (8 mm) - I terminal (S/N 5001~5333)
95ZV62017 - R terminal (S/N 5334~)

65ZV62016

When the starter switch is turned to ON or the Start Engine motion-active circuit:
position, the battery relay is turned on. When the starter
switch is set to the OFF position, the alternator stops When the starter switch is turned OFF, the battery relay
generating power, and the battery relay is automatically is automatically turned OFF since the command current
turned off so that the electrical circuits will not function. from the starter switch terminal ACC stops flowing and
the coil is demagnetized. Then the charging circuit from
If the battery relay was not used, a large amount of cur- the alternator is shut down.
rent would be directly sent through the starter switch
when it is turned on. However, use of the battery relay However, the alternator is still generating power and the
reduces the amount of current because this relay needs load dump surge may be generated. This may damage
only a small amount of current to energize it. the related circuits and equipment. In order to prevent
this trouble, this circuit (1) is provided to hold the battery
relay in the "ON" position.
Battery relay operation

Starter switch

ACC B
From
charge circuit Battery relay
(B)
To main
circuit (E)
Battery

Suppression
diode 65ZV62028

Battery relay
Rated voltage DC 24 V
Minimum operating voltage 20 V or less
Release voltage 9 V or less

When current flows from the starter switch terminal

ACC, the coil will be energized, and the moving contact
will lower to close the main contact. As a result, current
will flow from the battery to the main circuit.
62-18
80ZV Function & Structure Electrical Group
Engine Start Circuit

Diode unit 1. Diode (2)

This diode is provided to prevent the roundabout
current from the alternator to the controller.

2. Diode (3)
WV: To battery relay This diode is provided to prevent the roundabout
WV
WR: To starter switch terminal ACC (VIA F15)
WR WP WP: To alternator current from the starter switch ACC to the alternator
I terminal (S/N 5001~5333) or R terminal (S/N
5334~).

Diode storage section

70ZV62017

The diode unit is incorporated in the milky white connec-

tor near the battery relay. It is provided for the following
purpose.

Neutral relay

1 2

SbP

L
RL

3 4 G

Internal connection dia.

Body black

K85ZV62008

Position of Between Between Rating DV 24 V

Starting
shift lever 1 and 2 3 and 4 Operating voltage 16 V or less
F or R Not energized OFF Impossible Reset voltage 2.4 V or more
N Energized ON Possible
Coil resistance 320

The structures of the neutral relay, back-up relay, horn

relay, width lamp relay, head lamp relay and the ride
control relay (option) are identical each other.

Note
The illustration shows the de-energized condition.

When the shift lever is in the N position while the starter

switch is kept at the Start position, the neutral relay is
magnetized and electric current flows from the battery
to the neutral relay / magnetic switch / voltage relay
through the starter switch terminal C.
 62-19
80ZV Function & Structure Electrical Group
Engine Start Circuit

Magnet switch

Rating 24V x 200A

M C

C C’

M’
M’ C’

70ZV62019

Note On the other hand since the battery relay is already ON

The illustrations show the de-energized condition. at this time, electric current flows from the battery to the
starter motor terminal C through the battery relay and
When the neutral relay is magnetized, electric current the magnetic switch, engaging the starter motor to start
flows from the battery to the neutral relay and the mag- engine.
netic switch through the starter switch terminal C. It
magnetizes the magnetic switch.

Voltage relay
Once the engine is started, the alternator starts generat-
ing electric power.
1
2 3 When electric current is supplied from the alternator R
terminal to the voltage relay, the voltage relay is magne-
tized and is turned OFF.
2

3
Consequently the magnetic switch turns OFF and no
electric current flows to the starter motor terminal C, dis-
1 4 engaging the starter motor.
4

70ZV62020

Note
The illustrations show the de-energized condition.

Voltage relay
Contact point closed 6V
Contact point open 9V
62-20
80ZV Function & Structure Electrical Group
Power Generating/Charging Circuit

Power Generating/Charging Circuit

Alternator
Engine Mechanical energy supply

The alternator driven by the engine rectifies, with 6

diodes, full waves in three phases of the AC output gen-
erated in the stator coil by the three-phase start connec-
tion (Y connection) into DC output, then supplies it as
Alternator Electrical energy conversion the electric power to the battery and the machine load.

In the electricity generated in the alternator, the voltage

Rotor coil fluctuates depending on the number of revolutions of
excitation current Generated power the engine and the load size if no measures are taken.
IC regulator
To prevent fluctuation, a regulator is integrated so that
Voltage adjustment the voltage supplied to the battery and the load circuit is
For battery relay

For rotor coil always constant.

initial excitation
Adjusted
voltage

operation

For
battery relay
operation
Starter
Load circuit operation

switch
Battery charge

<Load>

For rotor coil Battery

initial excitation 70ZV62021

The power generating/charging device and the charging

circuit consisting of an alternator, regulator, battery, etc.
generate and supply the power required to all electrical
units of the machine.
 62-21
80ZV Function & Structure Electrical Group
Transmission Control Circuit and Monitor Circuit

Transmission Control Circuit and Monitor Circuit

Controller

Input LED Output LED

Circuit protector

CN1 CN2
1 2 3 4 1 2 3
5 6 7 8 4 5 6
CN3(Blue) CN4(Blue)

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21

12 13 14 15 16 17 18 19 20 21 1 2 3 4 5 6 7 8 9 10 11
80ZV62023
62-22
80ZV Function & Structure Electrical Group
Transmission Control Circuit and Monitor Circuit

LED inspection windows

See the figure in the previous page for the pin assign- Connector CN1 (Input)
ment. Sym Sym
No. bol Signal No. bol Signal

IN (input circuit) OUT (output circuit) 1 F Shift lever F 12 E Ground

Sym- Sym- 2 R Shift lever R 13

bol Signal bol Signal
3 1 Shift lever 1 14 SS Speed sensor (AUTO)
F Shift lever position F F Forward
4 2 Shift lever 2 15 AC Air cleaner sensor
R Shift lever position R R Reverse
Engine oil pressure
1 Shift lever position 1 1 1st speed 5 3 Shift lever 3 16 EP
sw
2 Shift lever position 2 2 2nd speed Transmission oil
6 A Shift lever A 17 TT
temperature sw
3 Shift lever position 3 3 3rd speed
E/G water
7 P Parking switch 18 WT
A Shift lever position A 4 4th speed temperature sw
Trimmer solenoid valve: Alternator neutral
P Parking switch: Running D 8 I Inching switch 19 EA
ON in working voltage
S QUAD (shift) switch: ON 9 20 BP Brake oil pressure sw
Shift lever position: Input unit common
I Inching switch: ON N 10 G 21 S QUAD (shift) switch
ON in Neutral ground
Auto/manual switching Back-up relay: 11 + + 24 V IN
M RR
signal: manual ON in Reverse
Controller:
DD Ride control switch (OPT) X Connector CN2 (Output)
Warning relay (Normal)
Sym Sym
Dig sw (Malfunction Ride control solenoid No. bol Signal No. bol Signal
MR DD
Recall) valve (OPT)
Clutch solenoid valve
Reset sw (Malfunction 1 F 12 A Auto (lamp)
MC BZ Buzzer F
Clear)
Clutch solenoid valve
BP Brake oil press.: Normal XX Controller: Normal 2 R 13 B Brake (lamp)
R
Air cleaner sensor: Clutch solenoid valve
AC SS Speed sensor input signal 3 1 14
Clogged 1
EG Clutch solenoid valve
Engine oil pressure sw: 4 2 15 AC Air cleaner (lamp)
EP below 0.07 MPa 2
Inspection window
(0.7 kgf/cm2) (10 psi) (7 segment display) Clutch solenoid valve Engine oil pressure
5 3 16 EP
3 (lamp)
Transmission oil
TT temperature sw: Clutch solenoid valve Transmission oil
6 4 17 TT
above 120ºC (248ºF) 4 temperature (lamp)

Water temperature sw: Trimmer solenoid E/G water

WT 7 D 18 WT
above 101ºC (215ºF) valve temperature (lamp)

Steering circuit press. 8 NR Neutral relay 19 BZ Buzzer

SP (Emergency steering)
9 RR Back-up relay 20 NL Neutral lamp
(OPT)
Controller failure
SE Speedometer (Not USA) 10 X 21 W Central alarm lamp
alarm relay
SO Speedometer (Not USA) 11 Solenoid return
Alternator neutral voltage:
EA
Power generation
 62-23
80ZV Function & Structure Electrical Group
Transmission Control Circuit and Monitor Circuit

Connector CN3 (Input)

No. Symbol Signal
1 MR Diag sw (Malfunction recall)
2 A/M Auto/manual switching signal
3 SE Speedometer ground (Not used in USA)
4 SO Speedometer output (Not used in USA)
5 MC Reset sw (Malfunction clear)
6 E 1·2·5 COM ground
7 SC Odometer converter
8

Connector CN4
No. Symbol Signal
1 DDI Ride control switch
2 DDO Ride control relay
3 OPT (Spare) Solenoid valve (OPT)
4 SPI Steering circuit pressure (OPT)
5 SPO Steering circuit pressure warning lamp (OPT)
6 SPS Emergency steering relay (OPT)

Connect No.2 and No.6 terminals of connector CN3

using a jumper wire to cancel the automatic shift func-
tion.
62-24
80ZV Function & Structure Electrical Group
Transmission Control Circuit and Monitor Circuit

Controller connection diagram

ACC’ E
PARKING SOLENOID
F5 L (100)
10A (BY) (132)

(116)
ACC’ LB (109) LR LR (130)
F F
LBr (131)
(111) LBr
R

CONTROLLER
R
N
R F

SHIFT LEVER
(132)
(112) (BY)
LY
1
(132)
(BY)
(113)
LG 1
2 23A
(133)
Transmission clutch 1 LY
solenoid valve LG (134)
(114) LO 2
3 LO (135)
3
LW (136)
A
(149) PARKING
(110) LW (GO)
4 P S/W
(144) SHIFT S/W
(YL)
S
(BY)
(115) LP
D SPEED (132)
(137) Y
Instrument panel SS
indicator lamp (138) Y

(SbP)
NR NR

LgW
Neutral relay X X

Controller failure relay (122)

(YV)
DD DD
(171) (172)
Back-up relay (121)
(LB) SbY [SbY]
RR RR BP BRAKE OIL
PRESS.
(159)
(SbY) Gy (173)
B EP E/G OIL PRESS.
F13 (160)
(Gy) GyG (174)
EP WT E/G WATER
TEMP.
(161)
(GyG) GyL (175)
WT TT T/M OIL TEMP.
(162)
(GyL) LgL (176)
TT AC AIR CLEANER
Instrument panel
indicator lamp (163)
(LgL)
AC A/M A/M SWITCH
(123)
(LP)
AUTO A SC SELECT SWITCH
(124) SO
(GR) SPEEDOMETER (Not in USA)
N N SE
(158) WL (019)
(GyB) EA
CENTRAL W ALTERNATOR
ALARM TERMINAL R
LAMP (154)
(GyW)

(400) RIDE CONTROL

Br
F3
(155) (GyY)

(151) (152)
LLg (LgR) (132)
I (BY)
BZ T/M
BUZZER CUT OFF
(141)
LgBr

(153)
(LgY)

(157)
(LgW) X

CONTROLLER FAILURE
(149) (132)
ON (BY)
(GO)
CONTROLLER (108) (148) OFF
(Lg) (SbW) ON
F13
PARKING OFF
(100) SOLENOID
L PARKING S/W
F5
LgG E
(147)

80ZV62011
 62-25
80ZV Function & Structure Electrical Group
Transmission Control Circuit and Monitor Circuit

Controller function
Forward/reverse (F/R) shifting and speed change

From T/C pump

LED (indication: F) F/R clutch solenoid valve

N +Vcc
R F F Clutch pressure regulator valve
+24 V
LED
Shift lever

R Surge
(indication: F)
suppression
(For input diode
detection) Speed clutch (incorporated
solenoid valve in solenoid To solenoid valve bank
1
A valve)
32 1 Clutch piston
Speed
LED (indication: S) indicator lamp
(instrument panel)
+24 V 2
Shift switch
LED
(indication: 2) Drain Clutch control solenoid valve
3
energized clutch engage
Speed de-energized clutch disengage
LED (indication: SS) 4
sensor

Common ground

+24 V

AUTO indicator lamp

ON when shift lever in A position

80ZVE62013

Each clutch has one solenoid valve for transmission Operation error preventive function
control. When electric current flows through the sole- (Simultaneous input of two or more com-
noid valve, the clutch oil is fed into the clutch piston mands)
chamber. When the piston operates, the clutch is
engaged. When the current stops flowing through the If both the forward and reverse commands are input at
solenoid valve, the oil is drained from the clutch piston the same time due to a problem, the forward and
chamber, and the clutch is disengaged. reverse clutches will not function. In addition, if two or
more speed commands are input at the same time, all
Input detection speed output command comes to OFF. As a result, no
speed clutches will function.
When the shift lever is set to the F (forward) position,
electric current of input detection signal is sent from the Since two conflicting input LED's will be on at the same
transmission controller to the grounding circuit inside time, troubleshooting is easier.
the transmission controller via shift lever contact F. The
transmission controller, therefore, judges that the shift
lever is set to the F (forward) position. There is no shift
lever contact for the R (reverse) input circuit and electric
current will not flow. In this status, the forward (F) indi-
cator lamp will light, and the reverse (R) indicator lamp
will not light.

For the speed change, the transmission controller

judges the set speed position of the shift lever in the
same way as described above.
62-26
80ZV Function & Structure Electrical Group
Transmission Control Circuit and Monitor Circuit

Shift lever

2 1

Forward F

KNIGHT BEAM CO,LTD

JAPAN
>PAMXD6-G50<
Neutral N

BM51-111
Reverse R

1st speed

2nd speed

3rd speed
Auto

Grounding for
speed change side (B)
3
1st speed (GW) 2nd speed (GL)
Auto (G) 3rd speed (GY)
F (GR) Unused
R (GB) Grounding for
F/R side (BY)

70ZV62025

1. Bracket assembly Operator controlled shifting from 2 1 2 in either "2"

2. Grip or "A" is done by momentarily depressing the QUAD
3. Connector switch on the boom lever.

The shift lever has two direction and four speed posi- Shift lever neutral (N) position
tions; forward and reverse (F and R) and "1", "2", and
"3" speed positions are respectively used for 1st, 2nd, The shift lever has no neutral (N) contact.
and 3rd fixed speeds. The "A" speed position is used
for the variable speed where the 2nd through 4th speed Therefore, if neither the forward nor the reverse (F and
clutches are automatically changed in both the forward R) signal is input, the controller will judge that the shift
and reverse operation. lever is at the neutral (N) position.
 62-27
80ZV Function & Structure Electrical Group
Transmission Control Circuit and Monitor Circuit

Operation of solenoid valve Automatic shift

Clutch solenoid valve Shift up

A 10.8 N-m (1.1 kgf-m) (8 lb-ft) Shift down
Speed
4

3
+ side

K W E 6 K- 21/ 2
- N
SKM6
G24D

17.5 14.5 9.5 7.5 0 8 10 15 18

– side
Reverse Speed km/h Forward
View from A
Automatic shift map (standard value) 80ZVE62016

35 N-m (3.6 kgf-m) (26 lb-ft)

When the shift lever is set to A, the AUTO indicator lamp
in the cab will light and one of the 2nd through 4th
80ZV62012
speed solenoid valves will be automatically energized
according to the machine speed. In addition, the speed
Solenoid valve (with built-in diode) indicator lamp will light. The input signal for automatic
Rated voltage DC 24 V shift is controlled by the pulse generated by the speed
Coil resistance value Approx. 27 sensor.
While the speed sensor is transmitting the pulse, the
When the input signal is transmitted, the output circuit of "SS" LED indicator flashes according to the pulse.
the corresponding solenoid valve is connected to the
grounding circuit inside the controller. As a result,
power is supplied to the solenoid valve and the clutch is
engaged. At the same time, the speed indicator lamp in
the cab lights. In addition, the LED indicator of the cor-
responding output circuit lights on the controller.

Note that when the parking brake or inching brake is

applied, the forward or reverse (F or R) clutch solenoid
valve is turned off and the transmission is set to neutral.
62-28
80ZV Function & Structure Electrical Group
Transmission Control Circuit and Monitor Circuit

Machine speed sensor

Clearance adjustment
0.15~1.4 mm (0.006~0.055 in)

70V2U62008

Internal resistance * 2.3±0.2 k (25ºC) (77ºF)

* Internal resistance changes greatly with temperature. At lower tem-

perature resistance is lower. At operating temperature the resistance
increases.
If resistance is 0 or the speed sensor is defective.

The detector is adjacent to the transmission output

Machine speed sensor gear. The pulse voltage is transmitted to the transmis-
(proximity switch)
sion controller.

Note
To prevent electronic "noise" from other sources that
may corrupt signal, "twist" the wire from sensor all the
way to the T/M controller.

K80ZV62003
IMPORTANT
Make sure to check the adjusted clearance when
replacing the sensor. Shims are available to adjust
clearance as needed.
 62-29
80ZV Function & Structure Electrical Group
Transmission Control Circuit and Monitor Circuit

Switching from automatic to manual QUAD (downshift) switch operation

QUAD (downshift)
switch

Input LED M Output LED

Inspection window

Circuit protector
Jumper wire
80ZVE62017

CN1 CN2
1 2 3 4 1 2 3 The QUAD switch is attached to the boom control lever.
5 6 7 8 4 5 6
CN3(Blue) CN4(Blue) In any operation mode, pressing the QUAD switch dur-
ing 2nd speed operation shifts the 2nd speed to 1st
speed. After that, if the QUAD switch is pressed again,
70ZV62029
the speed is changed from the 1st to the 2nd, or to
move the shift lever to neutral or to the opposite direc-
tion, the speed will be changed to the 2nd again.
The machine has automatic shift cancellation function
for troubleshooting. Connect No.2 and No.6 terminals Note that when the speed is shifted, the "S" LED indica-
of the controller connector CN3 using a jumper wire to tor of the controller will momentarily light (blink).
cancel the automatic shift function. The "M" input LED
indicator of the controller will light and the mode will be
switched from automatic to manual. Position "A" of the QUAD switch
shift lever, therefore, is fixed to the 4th speed.

Connect No.2 and No.6 terminals of connector CN3

using a jumper wire to cancel the automatic shift func-
tion.
YL

BY

70ZV62031

Max. voltage DC 24 V
Allowable value
Current 10 mA

The QUAD switch is of the momentary type. It is spring

loaded to the "OFF" position.
62-30
80ZV Function & Structure Electrical Group
Transmission Control Circuit and Monitor Circuit

Transmission cut off (Declutch)

Clutch cut-off switch

Transmission controller
+ 24V
LED
Forward/reverse clutch
F13 solenoid valves
+ Vcc
F
Transmission cut-off (Indication: I)
Monitor lamp
R

Pressure switch
for inching (declutch)

80ZVE62018

While the transmission cut off switch on the instrument

panel is ON (monitor lamp ON), pressing the brake
pedal actuates the pressure switch (inching switch),
turns off the power of the solenoid valves of the forward/
reverse clutches (F, R) by way of the T/M controller, and
sets the transmission to the neutral status. At this time,
the controller LED (indication: I) lights.

When the clutch cut off switch on the instrument panel is

set to OFF, the transmission cut off function is disabled
and the brake pedal is dedicated to braking.

At this time, the monitor lamp on the instrument panel is

Pressure switch
for declutch
no longer illuminated.

Pressure switch
for stop lamp

Left brake valve

K80ZV52013
 62-31
80ZV Function & Structure Electrical Group
Transmission Control Circuit and Monitor Circuit

Pressure switch for inching (declutch)

(S/N 80C4-5001~5050) Pressure switch specifications

Contact Normally open

1 2 3 4 5 6 7 8 9 10 11 12 13 Voltage (VDC) 24
Current (A) 2.3 (MAX.)
Resistance ( ) 10.4
16
Operating pressure
1.1±0.15 (11±1.5) (159±21)
MPa (kgf/cm2) (psi)
17
Return pressure MPa (kgf/cm2) (psi) 0.9±0.1 (9.1±1.0) (130±14)
A

View A

15 14
95ZV62047

1. Case 10. Terminal

2. Seal film 11. Terminal
3. Packing 12. Base
4. Disc 13. Cover (connector)
5. Inner cover 14. Guide
6. Guide pin 15. Stopper
7. Spring 16. Connector terminal
8. Contact 17. Housing seal
9. Contact

(S/N 80C4-5051~)

1 2 3 4 5 6 7 8 9 10 11 12 13

14

95ZV52056

1. Case 8. Contact Pressure switch specifications

2. Seal film 9. Contact
3. Packing 10. Terminal Contact Normally open
4. Disc 11. Terminal Voltage (VDC) 24
5. Inner cover 12. Base Current (A) 3.5 (MAX)
6. Guide pin 13. Cover Resistance ( ) 6.9
7. Spring 14. Connector
Operating pressure
0.5 ± 0.1 (5.0 ± 1.0) (71.1 ± 14.2)
MPa (kgf/cm2) (psi)
Return pressure
0.3 ± 0.05 (3.0 ± 0.5) (42.7 ± 7.1)
MPa (kgf/cm2) (psi)
62-32
80ZV Function & Structure Electrical Group
Transmission Control Circuit and Monitor Circuit

Back-up alarm

+24V

+24V F4 Back-up lights

IN 15A
Circuit
LED protector

+Vcc +24V Back-up relay

R
N
F
(Indication: R) 3 4
Back-up buzzer
Shift lever

1 2

F13
5A
4 1
(A) 3 2
LED
(Indication: RR)
+24V

70ZVE62015

When the shift lever is set to the reverse (R) position,

the coil of the back-up (or reverse) relay will be ener-
gized, and the main contact will be closed. The back-up
lamp, therefore, will light, and the buzzer will sound.

Back-up relay

1 2
LB

Lg
RL

3 4

Chassis side
Body black Elec. circuit coupler

K85ZV62009

Note Shift lever

Between 1 and 2
Between Lamp and
This relay is identical to the relays for neutral, back-up, position 3 and 4 buzzer
horn, head light, machine width lamp and ride control R Electric power supply ON ON
(option). F or N No electric power supply OFF OFF

They may be interchanged for testing purposes. Rating DC 24 V

Operation voltage 16 V or less
Reset voltage 2.4 V or more
Coil resistance 320
 62-33
80ZV Function & Structure Electrical Group
Transmission Control Circuit and Monitor Circuit

Parking brake

5A
+ 24V
F13
P Monitor lamp

Parking (ON)
Parking brake

Running (OFF) Cylinder

Parking
switch

ON + Vcc
OFF F
LED 10A P
Indicator [P] F5
R

+ 24V

70ZVE62016

The parking brake solenoid valve activates the parking

brake.

Parking switch ON: Parking switch OFF:

When the power of the solenoid valve is turned off, no When the power of the solenoid valve is turned on, oil
oil will be fed to the oil cylinder. The spring inside the will be fed into the oil cylinder. The oil will depress the
cylinder applies force to make the brake apply (drum spring to release the brake. In addition, the "P" LED
type). In this condition, the input "P" LED indicator is indicator will light.
off. If the transmission shift lever is set to the forward or
reverse (F or R) position, the buzzer will sound and the
clutch will not be engaged.

Parking brake operation

Parking brake LED indicator of

Parking switch Monitor lamp Buzzer
solenoid valve controller
“Parking” position Sounds when shift No electric power Input “P” LED
Parking * P
(pulled up) lever is set to F or R supply indicator: Off
“Running” position Input “P” LED
Running Off No buzzer Electric power supply
(pushed in) indicator: On
*When the parking switch is set to "parking", the forward or reverse clutch is disengaged and set to neutral.
62-34
80ZV Function & Structure Electrical Group
Transmission Control Circuit and Monitor Circuit

Parking brake solenoid valve

Oil cylinder (brake actuator)

Solenoid (S/N 5001~5196)
B Knob
Solenoid (S/N 5197~)

Reducing
valve P

Manual release
T (counterclockwise rotation)
Spool
Seat Seat
face A face B Tank B

P T
Hydraulic circuit diagram K90ZV52012

Screen board
Solenoid valve specifications

Voltage DC24 V
Current 0.69 A
Front
Resistance 34.8

Park brake
Rear chassis (RH) solenoid valve

(S/N 5001~5050) K80ZV52007

Screen board

Front

Rear chassis (RH)

Park brake
solenoid valve

(S/N 5051~) K80ZV52008

 62-35
80ZV Function & Structure Electrical Group
Transmission Control Circuit and Monitor Circuit

Transmission controller failure warning Controller fault relay

Should the transmission controller stop working due to

any of the following causes, a dash mounted monitor
lamp lights up to give warning.

T/M controller failure monitor lamp

If a warning is given as a result of self-diagnosis of

the transmission controller
Body blue
The transmission controller has a self-diagnosis func-
tion incorporated in it, and if the computer program
becomes abnormal due to abuse or defect, a dangerous
condition may occur, the monitor lamp lights up and all
the outputs from the controller are turned OFF. In this
1 4

LgW
case, the LEDs on the output circuit side of the control-

L
ler will not be lit. Some input LEDs may still be operating
(ON).

LgW
B
2 3
If the circuit protector (CP) is turned OFF
Elect. circuit Chassis side
If the circuit protector is automatically turned OFF due to (normally closed) coupler
a short circuit, etc., in the output circuit, the monitor
lamp lights up and all the outputs from the controller are
turned OFF. In this case, the none of the LEDs on the K90ZV62010

controller will be lit.

Rating DC 24 V
Operation voltage 16 V or less
Replacement of the transmission controller Reset voltage 2.4 V or more
Coil resistance 320
If the monitor lamp lights up under the cause 1 above, it
is an indication that the transmission controller's pro-
gram has malfunctioned and the transmission controller
assembly must be replaced.

If the monitor lamp lights up under the cause 2 above,

the cause is NOT the transmission controller.

Once the cause is removed, the controller may be reset

and continue to be used.

To reset simply turn the circuit protector switch to "ON".

62-36
80ZV Function & Structure Electrical Group
Transmission Control Circuit and Monitor Circuit

Monitoring system
If a problem of a unit is detected while the engine is
running, a monitor lamp lights to inform the operator.

For some problems, the buzzer sounds also, and the

central alarm lamp flashes also.

When the starter switch is set to ON, all of the monitor

lamps are lit for 3 seconds and buzzer sounds to check
whether the monitor lamps are normal (not burn out).

Items to be monitored and operation condition

Monitor lamp
No. Item to be monitored Operation condition Buzzer Lamp test Remarks
Lighting Symbol
color

Defective controller (CPU)

1 Controller
Control Processor Unit
(red)

Unloader valve accumulator port

2 Brake oil pressure oil pressure 3.9 ± 0.5 MPa
(red) (40 ± 3 kgf/cm2) (569 ± 71 psi)

While engine running

3 Engine oil pressure 0.08 ± 0.01 MPa (0.84 ± 0.14 kgf/cm2)
(red) (12 ± 2 psi) or less for more than 2 seconds

101 ± 2 ºC or more
4 Engine water temperature (214 ± 4 ºF or more) —
(red) for more than 2 seconds

Torque converter oil 120 ± 5 ºC or more

5 (transmission) (248 ± 9 ºF or more) —
temperature (red) for more than 2 seconds

Filter resistance: 635 ± 58 mmAq

6 Clogged air cleaner or more (25 inches H2O) —
(red) for more than 2 seconds

7 Charging condition Defective charge system —

(red)

8 Central alarm For items 1~6, 9 — Flashing type

(red)

When operates steering pressure is

Steering oil pressure
9 less than 0.4 MPa (4 kgf/cm2) (57 psi)
(option)
(red) machine speed more than 2 km/h
 62-37
80ZV Function & Structure Electrical Group
Transmission Control Circuit and Monitor Circuit

Operation monitor lamps

Monitor lamp
No. Monitor item Lighting condition Remarks
Lighting Symbol
color

1 Parking Red When parking brake switch is set to ON

When transmission cut off switch is set

2 Transmission cut off Green For declutch
to ON

When working light (rear) switch is set

3 Working light Green
to ON

When starter switch is in the

4 Preheat Yellow
PREHEAT position

Turn signal indicator When turn signal lever (left) is

5 Green
(left) actuated

Turn signal indicator When turn signal lever (right) is

6 Green
(right) actuated

7 High beam Blue When head lamp is set to high beam

When transmission shift lever is set to

8 Auto shift Green
automatic position

When transmission shift lever is set to

9 Neutral Green
neutral position

When transmission shift lever is set to

10 Transmission status Yellow
corresponding gear (1~4)

11 Ride control Green When ride control switch is set to ON (Option)

Caution on storage of individual instrument panel

Pointer axis
Gauge pointer
IMPORTANT Axis hole
Main body
When storing the instrument panel individually, make frame
sure that the panel face (transparent face) faces
upward.
If the panel face faces below the vertical direction, the
damper oil may leak from meter pointer axis holes. Damper
oil Magnet
Meter

70ZV62039
62-38
80ZV Function & Structure Electrical Group
Instrument Panel and Switch

Instrument Panel and Switch

Instrument panel

1 24 23 20 5 22 6 21 2 26 4 11 12

13

37 33

38 34

14
15
39 36
16
17

31 32 25 9 10 8 3

K80ZV62004

1. Tachometer 21. Turn signal indicator lamp (right)

2. Engine coolant temperature gauge 22. High beam indicator lamp
3. Torque converter oil temperature gauge 23. Auto shift indicator lamp
4. Fuel gauge 24. Neutral indicator lamp
5. Central warning lamp 25. Transmission status monitor
6. Parking brake indicator lamp 26. Hour meter
7. — 27. —
8. Transmission cut off selection indicator lamp 28. —
9. Working light indicator lamp (rear) 29. —
10. Preheat indicator lamp 30. —
11. Controller warning lamp 31. Ride control selector indicator lamp (option)
12. Brake oil circuit warning lamp 32. Steering circuit error warning lamp (option)
13. Engine oil pressure warning lamp 33. Working light switch (front)
14. Engine coolant temperature warning lamp 34. Working light switch (rear)
15. Torque converter oil temperature warning lamp 35. —
16. Air cleaner clogging warning lamp 36. Reversal fan switch (option)
17. Charge warning lamp 37. Emergency flasher indicator lamp switch
18. — 38. Transmission cut-off selector switch (Declutch)
19. — 39. Ride control switch (option)
20. Turn signal indicator lamp (left)
 62-39
80ZV Function & Structure Electrical Group
Instrument Panel and Switch

Instrument panel rear surface

CN4
CN1 L13 CN3
1 4 L11 29 48
L12
8P L20 12P 16P
L1 58 57
5 8 L14 L10 35 56
Hour L10 L10
L2 meter
L10 L15 S
L21
L3
L16 E V
L4 S S
L17 L10
L5 E V E V
Fuel gauge Engine water temperature Tachometer
L18
sensor
L6 L10 L10
L19
L7 S
CN2
L8 9 18 L22 L23 L24 L25 L26 L27
E V 20P
Transmission oil
L9 temperature sensor 19 28

Layout of connector pins (Instrument panel side)

CN1(8P) CN2(20P) CN3(12P/16P) CN4(2P)

A4 A5 A6 A7 A8

1 2 3 4 9 10 11 12 13 14 15 16 17 18 29 30 31 32 33 34 41 42 43 44 46 47 48
58 57
5 6 7 8 19 20 22 23 24 25 26 27 28 35 36 37 38 39 40 49 50 53 54 55 56
70ZV62041

Pin Lamp Pin Lamp Pin Lamp

Signal Signal Signal
No. No. No. No. No. No.
1 — L9 21 — 41 AUTO lamp L20
2 Charge lamp L7 22 Fuel gauge (sensor) — 42 — L16
3 Air cleaner clogging alarm L6 23 — — 43 Tachometer converter (+) —
4 T/M oil temperature alarm L5 24 — — 44 Tachometer converter (–) —
5 Engine water temperature alarm L4 25 — — 45 —
6 Engine oil pressure alarm L3 26 — — 46 Transmission cut-off lamp (Declutch) L17
7 Brake alarm L2 27 — — 47 Preheating lamp L19
8 Controller failure alarm L1 28 GND (-) — 48 Work lamp L18
9 +24 V power supply — 29 +24 V power supply — 49 Central alarm lamp L14
10 Emergency steering (optional) L22 30 — — 50 GND (–) —
11 Ride control (optional) L23 31 — — 51 —
12 — L25 32 — — 52 —
13 — L24 33 — — 53 High-beam lamp L12
14 — L26 34 Neutral L21 54 Turn signal (left) lamp L13
15 — L27 35 GND (-) — 55 Turn signal (right) lamp L11
16 Engine water temperature (sensor) — 36 1st speed indication — 56 — —
17 T/C(T/M) oil temperature gauge (sensor) — 37 2nd speed indication — 57 Hour meter (–) —
18 — — 38 3rd speed indication — 58 Hour meter (+) —
19 Instrument panel illumination L10 39 4th speed indication —
20 — L8 40 Parking brake lamp L15
62-40
80ZV Function & Structure Electrical Group
Instrument Panel and Switch

Gauge circuit Sensors respectively detect the temperature and fuel

level, and then convert them into electric signals. The
signals are transmitted to the corresponding gauges
that indicate the transmitted values.

Controller
Note
If a gauge is removed from the panel, the resistance
between the terminals will differ from the standard value
shown in the table.
Grounding S Power supply
24V

E V 15V

Viewed from rear surface of instrument panel

K90ZV62016

Gauge Engine water temperature T/C, T/M oil temperature Fuel level

110ºC(230ºF)
97ºC(206ºF) 100ºC(212ºF)
100ºC(212ºF) 120ºC(248ºF)
35ºC(95ºF) 103ºC(217ºF)
50ºC(122ºF)
125ºC(257ºF)

Indication

White Red Red White

White

Resistance
120~125 75~80 115~120
between S and E ( )
Resistance
120~125 85~90 115~120
between S and V ( )
Resistance
170~190 130~150 165~170
between E and V ( )

Temperature sensor
(For engine water temperature and torque converter
oil temperature)

Temperature of 60 80 100 120

detection part (ºC) [140ºF] [176ºF] [212ºF] [248ºF]
Resistance ( )
between terminal 56.3 29.5 16.5 10
Flat terminal and body
Thermistor

95ZV62066
 62-41
80ZV Function & Structure Electrical Group
Instrument Panel and Switch

Fuel level sensor

Float arm
Float

FULL
Highest position

(13.54 in)
344
1/2

(3.05 in)
77.5
(A)

(7.7 in)
195.5

(13.54 in)
1/4

344
Support

Lowest position

EMPTY

85ZV62014

The sending unit float arm in the fuel tank moves by the
fuel level movement in the tank. The contact installed on
the float arm axis back side (A) also moves by
contacting the resistance wire. The contact position is
Fuel gauge
F13 fixed, based on the float position and the fuel level.
When the fuel level becomes low, the resistance value
5A rises accordingly.
The position of the fuel gauge pointer is decided by this
resistance value, and the fuel gauge shows the fuel
Fuel level sensor amount left in the tank.
E
Fuel level circuit Float position FULL 1/2 1/4 EMPTY
+1.0
80ZVE62022 Resistance ( ) 10 - 0.5 (32) 49.5±4 85 +100

Note
Figure in ( ) is for the reference resistance, at 1/2 way
position in sweep.
62-42
80ZV Function & Structure Electrical Group
Electrical Detent Circuit

Electrical Detent Circuit

Bucket leveler After dumping, if the control lever is set to the "rollback"
position, the control lever will be held at that position
until the bucket is tilted to the set angle. This is
because the detent magnet in the pilot valve is
Detent solenoid
(Pilot valve Detent energized so that the holding plate connected to the
S/N 5271~) solenoid spool is held by the magnetic force.
(Pilot valve
S/N 5001~5270)
When the bucket is positioned at the set angle, the rod
will retracts from the proximity switch. The proximity
switch, turned off, and the coil of the pilot valve is de-
energized and demagnetized. The control lever is auto-
matically returned to the neutral position by the spring.

As a result, the bucket is set to the selected digging

angle automatically.

The bucket digging angle can be arbitrarily adjusted by

loosening bolts and moving a plate equipped with the
proximity switch.
Multiple control valve K90ZV62011
Bucket digging angle Dimension A
-7º 6 mm (0.24 in)
0º 51 mm (2.01 in)
+12º 134 mm (5.28 in)
Bucket cylinder

When installing the proximity switch

- Clearance between the proximity switch and the rod

A
Proximity Rod (detected (detecting element):
Adjusting Indicator lamp
plate switch object) 5 ± 2 mm (0.197 ± 0.079 in)

- Attach the proximity switch so that the indicator lamp

5+2 mm (LED) comes to the bottom side so that the lamp sta-
tus can be visually checked.

- :
Clearance between rod
and proximity switch K85ZV62011
Proximity switch: 19.6 N-m (2 kgf-m) (13 lb-ft)
 62-43
80ZV Function & Structure Electrical Group
Electrical Detent Circuit

Boom kick-out

Boom kick-out unit Float

Adjusting plate

Connector When the control lever is set to the "float" position, the
control lever will be held at that "float" position. For the
"float" position, manually reset the control lever. The
float magnet is energized whenever the starter switch is
"ON".

Proximity switch
5±2 mm (0.197±0.079 in) Boom 80ZV62022

While the boom is being raised, the control lever is held

at the "raise" position. When the boom is raised to the
set height, the boom kick-out unit automatically returns
the control lever to the "neutral" position. The detent
function and the units are the same way as those of the
bucket leveler.

Proximity switch

Adjusting the clearance

Proximity switch +24V

LED Br 1
Switch main Coil for detent
circuit
B2 inside pilot valve
L
3
+24V

Detection part
Operation indicator lamp (LED) 1(Br)

Detected object
Z
3(L) 2(B)

5±2 mm (0.197±0.079 in) View Z

K90ZV62012

Adjust the clearance between the sensor and the

adjusting plate to 5±2 mm (0.197±0.079 in).
In this condition, the operation indicator lamp (LED)
turns on, and the circuit between the switches (2) and
(3) is on.
62-44
80ZV Function & Structure Electrical Group
Electrical Detent Circuit

Detent solenoid
Three detent solenoids are installed in the pilot valve.
One detent solenoid, for the bucket leveler, is installed
in the pilot valve bucket side.
Two detent solenoids, for the boom kick-out and float,
are installed in the pilot valve boom side.

(S/N 80C4-5001~5270) (S/N 80C4-5271~)

Solenoid Steel ball for detent

Plate

Push rod

Detent solenoid
Lock nut
95ZV42014
Disc
Fixing disc

Voltage DC 24 V
Coil resistance 238±10
K90ZV62013

Voltage DC 24 V
Coil resistance 62±3
 62-45
80ZV Function & Structure Electrical Group
Diode

Diode
Symbols Open circuit, failed in open position.

+24V
Switch
+ Solenoid
[Anode] [Cathode]
Surge voltage

(forward direction) Diode

Current flow
(backward direction)
Current flows while the diode is disconnected.
(The solenoid is energized, however the surge voltage
70ZV62051
is not absorbed. This damages electrical parts.)70T2U62011

Normal A diode is an electronic part which makes the current

flow in one direction.
Current flow
The + side is called "anode", and the - side is called
"cathode". The current can flow only in the direction
from the anode to the cathode.
+24V
Switch
Solenoid
When a diode is connected in the current flow direction,
it is called forward direction. When a diode is connected
in the current non-flow direction, it is called backward
direction.
Diode

Current flows while the diode is normal Some electrical parts, as solenoid valves, buzzers,
(The solenoid is energized.) 70ZV62052 relays, all equipped with electromagnetic coils may gen-
erate a surge voltage caused by counter electromotive
force when the power is turned off. This surge voltage
Short-circuit, failed in closed position.
may cause malfunction of equipment.

Diodes are provided to prevent such a malfunction.

+24V However, if a diode is damaged and short-circuited (or

Switch fails closed) in its inside, electronic parts may be
Solenoid harmed.

Therefore, if a malfunction occurs in electrical equip-

Diode ment, electrical connection diagrams should be referred
to first, to determine and repair the cause. If a diode is
Current flows through the diode with smaller resistance. provided in the electrical equipment, the diode should
The solenoid is not energized. be checked for damage.
95ZV62074
62-46
80ZV Function & Structure Electrical Group
Diode

Diode check method Caution for diode check method

Continuity check mode

When checking the continuity by continuity check mode

of volt-ohm-ammeter, only in case that the resistance is
Coil
about 300 or smaller, the continuity is detected.

If the continuity check mode of volt-ohm-ammeter is

+
used to check the continuity of diode with 500~600 ,
no continuity is detected both ways.
+
Analog type tester Use a volt-ohm-ammeter with diode mode for checking
diode continuity.
95ZV62129

12V 12V Diode check mode

30A

Battery
ECM
(1)
R1 BR F15 WR (2) (3) WP
B AC
R2 C 5A
(2)(3): Diode unit

Suppression diode
R1
Charge
circuit From alternator
- I terminal (S/N 5001~5333)
- R terminal (S/N 5334~)
B
Neutral
relay K90ZV62014

Forward check
Continuity is detected in the status shown in the figure.
Normal Continuity is not detected when tester terminals are con-
nected in opposite way.
Continuity is not detected in either way Disconnection
Abnormal
Continuity is detected in either way Short-circuit

Note
When the circuit tester is the digital (number indication)
type, exchange the positions of the terminals of the
tester during the check. Some solenoid coils contain
diodes inside the solenoid coil pack.

Backward check
85V2E62036

Forward check Backward check Judgement

Continuity (voltage value) Over level Normal
Over level Over level Open circuit
0 volt 0 volt Short-circuit
 62-47
80ZV Function & Structure Electrical Group
Diode

Resistance check mode

Analog type tester

R1>0 R2=
0 0

Forward check Backward check

Digital type tester

R1>0 R2=

R1

Forward check Backward check

Forward check Backward check Judgement

R (0<R< ) Normal
Open circuit
0 0 Short-circuit
62-48
80ZV Function & Structure Electrical Group
Diode

Surge voltage and surge suppres- Fig. 3

sion diodes
Surge suppression
Fig. 1 diode

Electromagnetic field Coil

forms when switch closes.
Current direction

Coil
Voltage
Battery

Current Switch or
transistor
Current [A]
Voltage [V]

K70V2J62006

Time [sec]

When the surge voltage was generated, it causes to

Load increase wear on the switch points.
115ZVE62032

During the coil is being activated by the transistor, when

Some electrical parts such as solenoid valves are the excruciating high voltage is loaded on the transistor,
equipped with a coil. the transistor may be broken.

When a coil is energized, an electromagnetic field is In order to absorb this surge voltage, connect the diode
formed. See fig. 1. parallel to the coil in the reverse direction against the
power supply.
Fig. 2
When the switch is off, the same amount of electric cur-
When the switch opens, the rent, that was flown till now, flows through the diode.
field collapses across the
coil windings. This electric current is attenuated gradually and finally it
Coil
Voltage reaches zero. That means no surge voltage is gener-
Battery

Current ated in the circuit.

Current [A]
Voltage [V]

This diode is called as flywheel diode.

ON OFF
Time [sec]

Surge voltage
Load

115ZVE62033

When the solenoid coil is de-energized, the field col-

lapses across the coil. The collapse of this electromag-
netic field across the solenoid coil generates an
unregulated voltage surge. See fig. 2.

This can damage transistors, contacts, and other elec-

tronic parts. (See connection diagram.)
 62-49
80ZV Function & Structure Electrical Group
Diagnostic System

Diagnostic System

Diagnostic system flow

Starter SW ON (Engine OFF)

Current
Abnormal
condition

Normal Warning lamp ON

2 seconds ON: Release switch to the "off"

position when the screen goes blank.
Diagnostic (Timing is critical.)
SW

Failure history indication

Warning lamp flashes on
and off every 3 seconds.

Reset SW
If more than one failure code is
memorized, the newer failure code
will flash first.
3 seconds ON: Release switch to the "off" In case no failure code memorized,
position when the screen goes blank. all warning lamps come on for 1.5
(Timing is critical.) seconds.

Failure history memorized is

deleted completely
(Buzzer sounds 2 seconds)

70ZV62056
62-50
80ZV Function & Structure Electrical Group
Diagnostic System

Diagnostic failure history memory

data
Warning monitor/control

1 2
3
4
5

6
7
8

80ZV62015

1. Auto shift indicator lamp 1. If there was some abnormality found more than 2
2. Central warning lamp seconds for T/M oil temp., E/G water temp., and air
3. Controller warning alarm cleaner during engine running, abnormal condition
4. Brake oil circuit warning lamp is memorized in the controller memory.
5. Engine oil pressure warning lamp
6. Engine water temperature warning lamp 2. After confirming the bulb is not burnt out, if there
7. Transmission oil temperature warning lamp was some abnormality found more than 2 seconds
8. Air cleaner clogging warning lamp for E/G oil pressure during engine running, abnor-
mal condition is memorized in the controller mem-
ory.

3. After confirming the bulb is not burnt out, if there

was some abnormality found for brake oil pressure
during engine running, abnormal condition is mem-
orized in the controller memory.
 62-51
80ZV Function & Structure Electrical Group
Diagnostic System

Failure code

The failure code is indicated in the failure code inspec-

tion window of the controller.

Code Failure Detection condition Mode

Shift lever F and R contact ON at the same

11 In case the failure continues for more than 3 seconds A
time

Shift lever any of more than two 1·2·3·4

12 The same as the above A
Transmission Input
Circuit Malfunction

contacts on at the same time

In case all 1·2·3·4 signal OFF continues for more

23 Shift lever all 1·2·3·4 contacts OFF A
than 3 seconds

25 QUAD switch malfunction In case the switch is ON for more than 10 seconds A

26 Inching switch malfunction In case the switch is ON for more than 3 minutes A

In case the failure continues for more than 2

31 Air cleaner element clogging B
Machine System Input Malfunction

seconds

32 Transmission oil temperature high The same as the above B

33 Engine water temperature high The same as the above B

In case the failure continues for more than 2

34 Engine oil pressure low B
seconds during engine running

In case the brake oil pressure is low during engine

35 Brake oil pressure low B
running

51 1st solenoid valve malfunction Output circuit is disconnected or short-circuited A

52 2nd solenoid valve malfunction The same as the above A

53 3rd solenoid valve malfunction The same as the above A

Transmission Output Circuit Malfunction

54 4th solenoid valve malfunction The same as the above A

55 F solenoid valve malfunction The same as the above A

56 R solenoid valve malfunction The same as the above A

57 D solenoid valve malfunction The same as the above A

72 Machine speed sensor malfunction Input circuit is disconnected or short-circuited A

81 F·1 solenoid valve malfunction Output circuit is disconnected or short-circuited A

82 F·2 solenoid valve malfunction The same as the above A

62-52
80ZV Function & Structure Electrical Group
Diagnostic System

Code Failure Detection condition Mode

83 F·3 solenoid valve malfunction The same as the above A

Transmission Output Circuit Malfunction

84 F·4 solenoid valve malfunction The same as the above A

85 R·1 solenoid valve malfunction The same as the above A

86 R·2 solenoid valve malfunction The same as the above A

87 R·3 solenoid valve malfunction The same as the above A

88 R·4 solenoid valve malfunction The same as the above A

FF No failure record memorized A

Malfunction mode symbol

Mode A
Transmission control input/output circuit malfunction.

1. If there was some abnormality during engine run-

ning, abnormal condition is memorized in the con-
troller memory.

2. If more than one failure code is in memory the new-

est failure code will be displayed first (1 time only).

Mode B
Malfunction at chassis side.

1. If there was some abnormality during engine run-

ning, abnormal condition is memorized in the con-
troller memory.

2. If the failure code memorized is more than one the

newer failure code flashes on and off first in order.
 62-53
80ZV Function & Structure Electrical Group
Diagnostic System

Diagnostic (T/M controller) failure code 6. Machine speed sensor malfunction code (code 72):
detection condition
Code 72 indicates the machine speed sensor is
internally open or the wiring between the sensor
1. Failure code indication for current failure:
and the controller is disconnected or broken.
If more than one failure code is stored in memory
7. No malfunction code recorded (code FF):
the current one is displayed first. To review older
If the diagnostic switch is installed and pressed and
failure codes switch ON the diagnostic switch.
there are no malfunction codes stored in memory
the display will be shown "FF". If the machine will
2. Shift lever failure detection codes (codes 11, 12,
not move and "FF" is displayed check the input
23):
LED's to be sure there are no open circuit (except
code 23 which is for speed circuits [1, 2, 3, A] only)
Codes 11 and 12 indicate a short circuit in either
from the shift lever will not be stored in memory.
the shift lever or the wiring. Code 23 indicates an
open circuit in the shift lever or a broken wire. The
- "FF" means "Fault Free". "88" is designed to light up
machine may operate normality in all but one
all 'bars' to let you know that they are working.
speed.
"PP" indicates that the problem recorded has been
purged.
3. QUAD switch malfunction code (code 25):

Normally the switch is not pushed for more than 10

seconds. If the switch stays ON (contacts closed)
for more than 10 seconds the controller considers it
to be a short circuit in the switch or its wiring. If, for
some reason, the operator does hold the switch
down for more than 10 seconds the code 25 will be
stored in the controller but the machine will operate
normally.

4. Inching (declutch) switch malfunction code (code 26):

When using the inching (also called declutch or

clutch-cutout) switch it is normal for it to be ON
(contacts closed) while the brake pedal is
depressed.
However, if the switch remains ON for more than 3
minutes the controller considers that there is a
short in the switch or its wiring. Should the operator
keep the pedal depressed more than 3 minutes the
malfunction code will be stored in the controller but
the machine will continue to operate normally.

5. Solenoid open circuit codes (codes 51~57, 81~88):

If the transmission solenoid coil is internally open,

has high resistance (more than 27 ), or a broken
wire between the controller and the solenoid coil,
the machine will not move in the gear that has the
open circuit (malfunction codes 51~57). The symp-
tom may be the same as 2 above. Read the mal-
function code to determine which malfunction has
actually occurred. If there is a problem for codes
51~57, or 81~88 that is occurring on machine, a
code will show in the window when machine is
operating.
62-54
80ZV Function & Structure Electrical Group
Diagnostic System

Diagnostic failure history indica- Failure history deletion

tion and deletion
When the starter switch is ON (but no engine started),
place the reset switch to ON position.
Failure history indication
About 3 seconds later, the auto shift indicator lamp
When the starter switch is ON (but no engine started), [AUTO] and all warning lamps on the instrument panel
place the diagnostic switch to ON position. light up and the indication of "FF" on the diagnosis dis-
play window comes to disappear. After that with inspec-
About 2 seconds later, the auto shift indicator lamp tion window blank, place the reset switch to OFF
[AUTO] and all warning lamps on the instrument panel position. (The timing is critical.) The indication of "PP" is
light up and the indication of "FF" on the diagnosis dis- displayed on the diagnosis display window of the con-
play window comes to disappear. After that with inspec- troller and at the same time the buzzer sounds.
tion window blank, place the diagnostic switch to OFF
position. (The timing is critical.) Then the failure history deletion is completed.
The failure code is displayed on the diagnosis display If fail to do this, no failure history deletion is completed.
window of the controller.

If fail to do this, no failure code is displayed on the diag-

nosis display window of the controller.
 62-55
80ZV Function & Structure Electrical Group
Diagnostic System

[Failure history indication] 2sec

Diag.sw
1.5 1.0
sec sec 3sec

Warning lamp
AUTO Each warning All warning
All warning lamps lamp lamp
(Except central
warning lamp)

Controller
(7seg)

1.0 1.0
sec sec

T/M controller Malfunction

Input/output circuit at chassis side
malfunction

[Failure history deletion]

Reset sw 3sec
2sec
Failure history deletion completely

Buzzer All warning lamps

(Except central
warning lamp)
All warning lamp

Warning lamp

Controller
(7seg)

1.5sec 2sec 3sec

70ZV62060
62-56
80ZV Function & Structure Electrical Group
Diagnostic System

Diagnostic switch
When performing the diagnostic procedure, connect the
diagnostic switch coupler to the controller as shown on
the next page.

Necessary parts

1. Diagnostic switch assembly (A)

Part Number
35020-20510
- Diagnostic sw
- Reset sw
- Harness assembly

2. Harness assembly (B)

Part Number
33191-52950
 62-57
80ZV Function & Structure Electrical Group
Diagnostic System

Connection procedure

Diag.SW Reset SW
OFF
ON

OFF
(A)
T/M Controller ON

G R
8P 21P 21P 6P

Y B
Connect

B
Y R

(B) Y R
B

70ZV62061
62-58
80ZV Function & Structure Electrical Group

MEMO
 63-1
80ZV Check & Adjustment Electrical Group

80ZV Check & Adjustment

Electrical Group

Cautions Regarding Electric Circuit Check ...........................63-2

Electrical Transmission Control System
Troubleshooting Flowchart ..............................................63-5
Transmission Controller Abnormal Operation Judgment ......63-6
Electrical Circuit Check .......................................................63-10
63-2
80ZV Check & Adjustment Electrical Group
Cautions Regarding Electric Circuit Check

Cautions Regarding Electric Circuit Check

Disconnecting or reinstalling con-

nector

Inserting waterproof round connector

80ZV63006

Removing square connector

80ZV63003

80ZV63007

1. Before disconnecting or reinstalling the connector,

Removing waterproof round connector be sure to turn the power off (turn the starter switch
80ZV63004
to OFF).

2. To disconnect a connector, firmly grab the connec-

tor, and press and hold the stopper claw. While
holding down the claw, pull out the connector in the
straight direction. Do not pull the electric cable or
wires. They may be damaged. Do not twist the con-
nector or the female terminal cover may be dam-
aged to cause poor contact.

3. When reconnecting, insert it until the stopper claw

clicks.
If the connector is not completely connected, it may
cause poor contact.
Inserting square connector
80ZV63005
 63-3
80ZV Check & Adjustment Electrical Group
Cautions Regarding Electric Circuit Check

Note
In corrosive environments (such as salt air, phosphate
plants, or fertilizers) the square type connectors will
require special coatings to prevent or minimize electrical
problems. Use only an approved sealant like Dow Corn-
ing 738 or Loctite "Ultra Blue".
Other silicone sealants may contain acetic acid which
may corrode the wiring.
(Hint: If the silicon has a vinegar type odor it has acetic
acid and should not be used.)
Use only a very small amount of di-electric grease if
needed.
63-4
80ZV Check & Adjustment Electrical Group
Cautions Regarding Electric Circuit Check

How to attach the probes of the

circuit tester

How to attach the probes of the circuit tester

to the square connector.
80ZV63008

How to attach the probes of the circuit tester

to the waterproof round connector. 80ZV63009

When checking the conductivity or the voltage, follow

the procedure below:

1. Square connector

Insert the probes for the tester to the wire side of

the connector. Do not insert the probes into the
open side of the connector. The damaged connec-
tor may cause poor contact.

2. Waterproof round connector

For the waterproof round connector, do not attach

the probes of the tester to the wire side because
the wire side is waterproofed. Attach the probes to
the open connector side. Do not force the probes
into the female side. The damaged connector may
cause poor contact.
 63-5
80ZV Check & Adjustment Electrical Group
Electrical Transmission Control System Troubleshooting Flowchart

Electrical Transmission Control System Troubleshooting

Flowchart
For a problem regarding transmission control, check the To check the electric control system, determine the
electric control system first, and then check the cause of the problem while referring to the flowchart
mechanical system. below, and then solve the problem.

Standard troubleshooting flowchart

Cause of problem

Is the "controller
failure" monitor On - The transmission controller
lamp on? failure. If the circuit protector in
the controller is off, the power
supply or output circuit is
off shortcircuited. Check for
damaged solenoid coils or their
wiring.

Check the other

monitor lamps.* Abnormal - The input circuit or one of the
input units is defective.
* Check that the monitor lamps are properly
turned on and off according to operation of the
Normal respective unit, such as shift lever and parking
switch.

Check the on/off

statuses of the
transmission Abnormal - The input circuit or one of the input
controller LED units is defective.
indicators.* - The transmission controller is
* Refer to the table "Transmission controller defective. (The defective controller
LED indicator". Also check for logged fault judgment standard is described on
codes. the next page.)
Normal

Check operation of
the output circuit Problem detected
- The output circuit or one of the
and output units.* (disconnection, etc.)
output units is defective.
* Measure the resistance of the output circuit
No problem and output units (solenoid valve, etc.) while
operating the input units.

Check mechanical
operation of the Problem detected - An output unit is defective.
output units.*
* Disassemble the output units
(solenoid valve, etc.), and check
No problem them for sticking.
Check the drive line and
the transmission for
mechanical problems.

70ZVE63009
63-6
80ZV Check & Adjustment Electrical Group
Transmission Controller Abnormal Operation Judgment

Transmission Controller Abnormal Operation Judgment

Transmission controller check When the output units (solenoid valve, etc.)
do not operate properly:
To judge whether the transmission controller operates
properly, follow the procedure below: Remove connector CN2 from the output side. Operate
the shift lever, parking switch, etc., and check the on/off
statuses of the transmission controller LED indicator.
IMPORTANT
When performing test 3, be careful not to arc across ON/OFF Input side No LED Normal LED Normal LED
status of
to other terminals. Damage to controller can result. LED Output side No LED Normal LED No LED
Use plug in connector pig-tail wires to do this with.
Judgment for controller Normal Abnormal
Defective
Defective
Defective transmis-
Cause input unit or
output unit sion control-
circuit
ler
When the "controller failure" monitor lamp Replace the
lights: Check the Check the
transmis-
input units output units
Solution sion
and the and the
controller
Under the condition, check the position of the circuit circuit circuit
assembly
protector switch (on or off). (After turning the starter
switch to the OFF position, turn on the circuit protector
switch.)

Circuit protector OFF ON

Judgment for Normal Abnormal

controller
Defective transmission
Power supply or output
Cause controller
circuit shortcircuited
(IC self-diagnosis)
Check the power sup- Replace the transmis-
Solution
ply and output circuits sion controller assembly
 63-7
80ZV Check & Adjustment Electrical Group
Transmission Controller Abnormal Operation Judgment

If the input units or circuit are not defective Directly inputting input signal

Shortcircuit (connect) the terminals of connector CN1

using the probes of the tester or a jumper wire.

Input signal Terminals to be connected LED

F 1-10 F

shift lever position

R 2-10 R

Comparable
1 3-10 1
2 4-10 2
Input LED Output LED
3 5-10 3
A 6-10 4
Parking 7-10 P
Inching (Declutch) 8-10 I

Circuit protector

CN1 CN2
1 2 3 4 1 2 3
5 6 7 8 4 5 6
CN3(Blue) CN4(Blue)
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21

12 13 14 15 16 17 18 19 20 21 1 2 3 4 5 6 7 8 9 10 11

70ZV62022

There is a strong possibility that the transmission con-

troller is defective. To check the transmission controller,
directly input the input signal, and then check the on/off
statuses of the transmission controller LED indicator. If
a LED indicator is not on, judge that the transmission
controller is defective. Replace it.

Set-up

Remove all the controller connectors, and then supply

power to connector CN1 (terminal 11: +24V/Terminal
12: Grounding).
63-8
80ZV Check & Adjustment Electrical Group
Transmission Controller Abnormal Operation Judgment

Transmission controller LED indicator

The transmission controller LED indicator should be on
as shown below if the transmission controller is operat-
ing normally and inputs are correct.

In running status

Only the LED's related to the transmission circuit are

shown.

Automatic shift

Speed change

QUAD switch
Normal running

switching
condition
Machine

Inching
(“A” shows automatic cancel
LED on shift position)
- - Related LED on
Remarks
(depending on
Forward Reverse
machine speed)
F F F F R R R R F R F1 F2 F F2 F2 R2 R2
position
lever
Shift

• • • • • • • • • • •
1 2 3 A 1 2 3 A 4 4 F2 R2 2 F1 R1
F Shift lever position • F
R Shift lever position • R
1 Shift lever position • 1
Input side LED window

2 Shift lever position • 2

3 Shift lever position • 3
A Shift lever position • A
P Parking switch LED on: In running status
S Shift switch (QUAD Sw) LED on: During switch operation only

I Inching switch
M Automatic shift cancel
DD Ride control (OPT) LED on: During switch ON
F Forward
R Reverse
1 1st speed
2 2nd speed
Output side LED window

3 3rd speed
4 4th speed
D Trimmer plug solenoid valve LED on: During clutch change only
N Neutral relay
RR Back-up relay (Reverse relay)

X Controller warning relay LED on: In normal condition

DD Ride control relay (OPT) LED on: M/C speed over 7 km/h (4.375 mph)

BZ Buzzer
SS Speed sensor input signal LED flashes depending on machine speed
 63-9
80ZV Check & Adjustment Electrical Group
Transmission Controller Abnormal Operation Judgment

In parking status
(During engine operation)
Circuit protector on when
controller failure alarm is
Usual parking
Circuit protector OFF
condition
Machine

LED on
- - Related LED on
Remarks
(depending on
machine speed)
position
Neutral
lever
Shift

on

F Shift lever position • F

R Shift lever position • R
1 Shift lever position • 1
Input side LED window

2 Shift lever position • 2

3 Shift lever position • 3
A Shift lever position • A
P Parking switch
S Shift switch (QUAD Sw)
I Inching switch
M Automatic shift cancel
DD Ride control (OPT) LED on: During switch ON
F Forward
R Reverse
1 1st speed
2 2nd speed
Output side LED window

3 3rd speed
4 4th speed
D Trimmer plug solenoid valve
N Neutral relay
RR Back-up relay (Reverse relay)
X Controller warning relay LED on: In normal condition
DD Ride control relay (OPT)
BZ Buzzer
SS Speed sensor input signal
63-10
80ZV Check & Adjustment Electrical Group
Electrical Circuit Check

Electrical Circuit Check

Shift lever input electrical circuit Disconnection check:

check Shift lever Check
position Terminals to be checked Judgment
result
Between terminals F and F/R
F
common grounding (BY)
Between terminals R and F/R
R
common grounding (BY)
Between terminals 1 and speed Conduc-
1
change common grounding (B) tive
Normal
Between terminals 2 and speed (Resis-
2 tance 0 )
change common grounding (B)
Between terminals 3 and speed
3
change common grounding (B)
Between terminals A and speed
A
change common grounding (B)

If the line is not conductive, judge that the switch or wire

is damaged or defective.

Shortcircuit check:

Shift lever Check

position Terminals to be checked Judgment
Connector B4 result
Grounding for Between terminals R and F/R
speed change side (B) F
common grounding (BY)

1st speed (GW) 2nd speed (GL) Between terminals F and F/R
R
common grounding (BY)
Auto (G) 3rd speed (GY)
Between terminals 1 and speed Non con-
1
F (GR) Unused change terminal other than 1 ductive
Normal
Between terminals 2 and speed (Resis-
R (GB) Grounding for 2
change terminal other than 2 tance )
F/R side (BY) 70ZV63002
Between terminals 3 and speed
3
change terminal other than 3
Check that the LED indicator corresponding to the shift Between terminals A and speed
A
lever position is on. change terminal other than A

LED Judgment If a section is conductive, judge that the switch is stick-

Corresponding LED indicator is on Normal ing.
Corresponding LED indicator is off Disconnection
Abnormal
Wrong LED indicator is on Shortcircuit In this case two or more signals would be sent at the
same time (e.g. forward and reverse; 1st and 3rd)
If the judgment is abnormal, follow the check procedure
below: <Solution>

If disconnection or shortcircuit is detected, replace the

<Step 1> Shift lever conductivity test shift lever assembly. The shift lever has no serviceable
parts and must be replaced. If the conductivity check
Set the starter switch to the OFF position, and then dis- reveals that the shift lever is not defective, go to step 2.
connect connector B4 so that the shift lever assembly is
disconnected. Perform conductivity test using a tester
(circuit tester).
 63-11
80ZV Check & Adjustment Electrical Group
Electrical Circuit Check

<Step 2> Checking conductivity of shift lever input

circuit cable Shift lever
Terminals to be checked
Check
Judgment
position result
F LR-BY (E111 to E102)
R LBr-BY (E110 to E102)
1 LY-BY (E109 to E102)
Conductive Normal
2 LG-BY (E108 to E102)
Shift lever circuit 3 LO-BY (E107 to E102)
A LW-BY (E106 to E102)

If a line is not conductive, judge that the cable is defec-

tive. Also check that only the above terminals are con-
ductive. Otherwise there could be a short circuit in the
Transmission controller wiring.

<Solution>

GW GL GY
Repair or replace the defective cable.
Input LED Output LED G B

GR GB BY

LR LBr BY
E111 E110 E102
Circuit protector
LW BY
E106 E102

LY LG LO
E109 E108 E107

3 1
CN1 CN2
B4

T/M controller INPUT

(see “abbreviation chart” page 62-22)
F R 1 2 3 A P I G +

E SS AC EP TT WT EA BP S

B Y LgL Gy GyL GyG WL SbY YL

H716 H120 F302 H122 F202 H106 H121 G101

LR LBr LY LG LO LW GO LLg BY/Y L

B409 B408 B403 B402 B401 B406 B306 A102

11 1
B304 D110
B405 H101
E1 B407
C701
G102
H706

90ZV63001

Connect connector B4 to the shift lever, and disconnect

connector CN1 from the transmission controller. Check
the conductivity of the cable connector terminals.
63-12
80ZV Check & Adjustment Electrical Group
Electrical Circuit Check

Inching (Declutch) input electrical

Input LED "I"
circuit check

Transmission
cut-off switch
Brake pedal
Judgment Remarks
Pressed
Released
down
Transmission cut-off monitor lamp Declutch
T/M cutoff S/W — Normal
1 — — Disconnect Inching impossible

Abnormal
2
3
5
4 ON
6 Defective Machine stays in
SW or short- the inching
7 4 5 6 circuit (declutch) mode
8 1 2 3
Inching function
— — Normal
LgY
A603
B
OFF cancel
Inching (declutch) switch LLg LgR
E104 C702 Abnormal Defective wiring
(S/N 5001~5050) 4
A1
1 On
2
LgR BY
1
— Off
A101 E102
C7

Inching (declutch) switch

(S/N 5051~) <Step 1> Checking inching switch
2 1
LgR BY C7
Y B A101 E102
Check that the brake oil pressure is normal. After that,
press down the brake pedal, and check the resistance
T/M controller INPUT of the inching switch at the connector C7.
(see “abbreviation chart” page 62-22)
F R 1 2 3 A P I G +
<Solution>
E SS AC EP TT WT EA BP S

B Y LgL Gy
H703 H103 H135
GyL GyG WL SbY YL
H134 H115 H107 H708 G101 If no continuity is detected, the switch is sticking or the
LR LBr LY LG LO LW GO LLg
B409 B408 B403 B402 B401 B406 B306 A102
BY/Y L
cable is disconnected.
11 1
B304 D110

Repair or replace the defective unit.

B405 H701
E1 B407
C701
G102
H709 K80ZV63001

Inching switch specification

Turn the transmission cut-off (Declutch) switch on the
(S/N 80C4-5001~5050)
instrument panel "ON". Note that the transmission cut-
Operating pressure MPa 1.1 ± 0.15
off monitor lamp will light if the lamp circuit is not defec- (kgf/cm2) (psi) (11.2 ± 1.5) (159 ± 21)
tive. Press down the brake pedal, and check the on/off Return pressure MPa 0.9 ± 0.1
status of the transmission controller "I" LED indicator. (kgf/cm2) (psi) (9.2 ± 1.0) (131 ± 14)
Resistance ( ) 10.4

WARNING (S/N 80C4-5051~)

Unexpected movement of the machine may cause an Operating pressure MPa 0.5 ± 0.1
accident resulting in injury or death. (kgf/cm2) (psi) (5.0 ± 1.0) (71.1 ± 14.2)
Be sure to observe the following items before starting Return pressure MPa 0.3 ± 0.05
(kgf/cm2) (psi) (3.0 ± 0.5) (42.7 ± 7.1)
work.
Resistance ( ) 6.9
- Position the machine on level ground, and lower
the bucket onto the ground.
- Block the tires with chocks to prevent them from
moving
 63-13
80ZV Check & Adjustment Electrical Group
Electrical Circuit Check

<Step 2> Checking transmission cut-off switch

assembly

Disconnect the A1 connector of the transmission cut-off

switch assembly from the instrument panel.

Perform conductivity test using a tester.

Conductivity test
Terminals to be checked Switch position Judgment
ON OFF
0 Normal
Between terminals 5 and
6 (Transmission control- Discon-
Abnormal

ler input) nect

Between terminals 2 and Short-
3 (Lamp circuit) 0 (other than
circuit

<Step 3> Checking cable

When no trouble found on both inching switch and

transmission cut-off switch, the cable or the connector is
defective.

<Solution>

Repair or replace the defective cable.

63-14
80ZV Check & Adjustment Electrical Group
Electrical Circuit Check

QUAD switch input electrical cir- The QUAD switch does not shift the speed
cuit check [Checking transmission controller input LED indicator]

Check that the transmission controller “S” LED indicator

lights instantaneously when the QUAD switch is turned
ON.

LED Judgment Remarks

ON Normal
OFF Abnormal Disconnect Shift change impossible
BY
YL

If the "S" indicator does not light:

E102
E112

1 Checking QUAD switch:

Disconnect the switch G2 connector. Check that the ter-

G1 minal line between 1 and 2 is conductive when the
switch is depressed.

<Solution>
T/M controller INPUT
(see “abbreviation chart” page 62-22)
If the switch is defective (non-conductive), replace it. If
F R 1 2 3 A P I G +
the switch is not defective, judge that the cable or con-
E SS AC EP TT WT EA BP S
nector between the control box and switch is defective.
Repair or replace the defective unit.
B Y LgL Gy GyL GyG WL SbY YL
H703 H103 H135 H134 H115 H107 H708 G101

LR LBr LY LG LO LW GO LLg BY/Y L

B409 B408 B403 B402 B401 B406 B306 A102

11 1
B304 D110
B405 H701
E1 B407
C701
G102
H709 80ZVE63003

[While traveling at the 2nd speed, turn on the QUAD

switch, and the speed will be shifted to the 1st speed.
(For both manual and automatic modes)] Turn the
switch ON again and the transmission should be shifted
back to the 2nd speed.
 63-15
80ZV Check & Adjustment Electrical Group
Electrical Circuit Check

Machine speed sensor input elec- Checking conditions

trical circuit check 1. Select an open site away from people, other equip-
ment and buildings.

2. Watch the transmission controller "SS" LED indica-

Gear tor while the machine is moving at 1~5 km/h.
Transmission
output gear
LED [SS] Judgment
Clearance adjustment Flashes according to the speed Normal
1.3 mm (0.05 in)
0.15~1.4 mm (0.006~0.055 in) Does not light (flash) Abnormal

Note
Tightening To prevent electronic "noise" from external sources that
torque may corrupt the signal, "twist" the wire from the sensor
39 N-m
(29 lb-ft) all the way to the T/M controller.

<Step 1> Checking sensor

Y Y M9
H709 H703

2 1 Installation adjustment:
T/M controller INPUT
(see “abbreviation chart” page 62-22)
Adjust the clearance between the sensor and the gear
F R 1 2 3 A P I G +
H7 to 0.15~1.4 mm (0.006~0.055 in).
E SS AC EP TT WT EA BP S

B Y LgL Gy GyL GyG WL SbY YL

H703 H103 H135 H134 H115 H107 H708 G101

LR LBr LY LG LO LW GO LLg
B409 B408 B403 B402 B401 B406 B306 A102
BY/Y L
Checking sensor for disconnection:
11 1
B304 D110
B405 H701
E1 B407
C701
Disconnect the sensor connector, and then measure the
G102
H709 80ZVE63004 resistance between the terminals.

Resistance Judgment
Approx. 700 (25 ºC) (77 ºF)* Normal
(Disconnection) 0 (Short) Abnormal

*Note
Machine speed sensor The speed sensor resistance varies greatly with temper-
(proximity switch) ature.
A hot sensor will have higher resistance, cold will
reduce the resistance.

<Solution>

If the sensor is defective, replace it. If the sensor is not

defective, the cable or connector between the sensor
and the transmission controller is defective.
K80ZV62003
Repair or replace the defective unit.

- Problem
The automatic shift function is not working.

The automatic shift function needs a speed signal.

[Transmission controller input LED indicator]

63-16
80ZV Check & Adjustment Electrical Group
Electrical Circuit Check

Clutch solenoid valve output elec- <Step 1> Checking solenoid valve
trical circuit check - Measuring coil resistance

- Problem Disconnect the connector from the solenoid valve,

A clutch will not engage. and then measure the coil resistance using a tester.
Note that a diode is incorporated in the coil.
Set the shift lever to the problem position. If the cor-
responding transmission controller input/output LED Coil resistance Judgment
indicator is properly turned on and off, judge that the Approx. 27 Normal
coil of the corresponding solenoid valve is discon- Disconnect short 0 Abnormal
nected, or the valve is sticking, or the cable of the
output circuit is disconnected or poorly connected. - Check valve for sticking

- Problem
The circuit protector is turned off. WARNING
Unexpected movement of the machine may cause an
The cable (power supply side) between the trans- accident resulting in injury or death. Be sure to
mission controller and the solenoid valve is shortcir- observe the following items before starting work.
cuited or the solenoid valve coil is internally - Position the machine on level ground, and lower
defective. the bucket onto the ground.
- Block the tires with chocks to prevent them from
- Problem moving.
The machine can run at only one shift lever position.
Be sure engine is off before checking.
The machine runs at a certain shift lever position,
though it does not run or runs too slow at any other
Push the manual operation knob to the ON position by
position. In this case, judge that the cable (negative)
hand, and then check that the spool operates smoothly.
of the solenoid valve is shortcircuited, or the valve is
If it does not operate smoothly, judge that the valve is
sticking.
sticking.

<Solution>

If the coil is disconnected or the valve is sticking,

replace the defective unit as an assembly.

<Step 2> Checking diode

Keep the starter switch OFF.

Use an analog (needle type) Volt-Ohm Meter (VOM)

with an Rx1 setting. Adjust the meter's zero setting.

Disconnect the solenoid valve connector and check the

continuity between the terminals.

Continuity is detected when the test

probes are placed as shown below.
Normal
Change in continuity by a few ohms is
detected by reversing the test probes.
Abnormal

No continuity detected in both directions Disconnection

Continuity detected in both directions Short circuit

 63-17
80ZV Check & Adjustment Electrical Group
Electrical Circuit Check

<Solution>

+side

K W E 6 K- 21/
- N
SKM6
G24D

-side
View from A

80ZVE63005

If the diode is defective replace the coil.

Note
Use an analog (needle) type meter for test.
63-18
80ZV Check & Adjustment Electrical Group
Electrical Circuit Check

<Step 3> Checking output circuit and cable Disconnect the connector from the problem solenoid
valve, and then set the starter switch to the ON position
(engine OFF; shift lever set to problem speed; parking
brake OFF). Measure the voltage of the connector ter-
minal on the cable side using a tester.
For trimmer
Example
F Measure the voltage between terminals LY and LB to
check the connector of the 1st speed solenoid valve.

4th Note
1st Power is supplied to a solenoid valve only when the shift
2nd lever is set to the corresponding position (when the out-
R
put LED is on). To check the 4th speed connector, be
sure to cancel the automatic shift function.
3rd

IMPORTANT
When measuring voltage, do not short-circuit two ter-
minals of a connector at the same time, as the elec-
tronic parts inside the controller may be damaged.
T/M controller OUTPUT
(see “abbreviation chart” page 62-22) Checking positive cable
A B AC EP TT WT BZ NL W

F R 1 2 3 4 D NR RR X COM Terminals to be checked Voltage Judgment

LR LBr LY
H208 H207 A511
LG LO LW LP SbP LB LgW
A510 H203 A508 H206 F703 F803 F003
LB
A512
Between terminals LY and Approx. 24 V Normal
H201 H202 A509 H204 H205 body grounding
LP SbY
A608 A306
LgL Gy
A302 A307
GyL GyG LgBr GR
A301 A308 G602 A501
GyB
A616 (For 1st speed solenoid) Approx. 0 V Abnormal
11 1

Checking negative cable

H2
E2

Terminals to be checked Voltage Judgment

T/M SOLENOID Approx. 1 V Normal
Between terminals LB and
VALVE
body grounding Approx. 24 V Abnormal
LR LB J1
F - + H208 H205

2 1

<Solution>
LBr LB J2
R - + H207 H205

2 1
If the voltage is abnormal, the cable may be broken. In
this case, check the connector, find a defective part,
1 - +
LY LB
H201 H205
J3 then repair or replace it.
2 1

LG LB J4
2 - + H202 H205

Cable color 2 1

(+) ( )
LO LB J5
F LR 3 - + H203 H205

R LBr 2 1

1 LY
LW LB J6
2 LG LB 4 - + H204 H205

3 LO 2 1

4 LW
LP LB J7
D LP D - + H206 H205

2 1

80ZVE63006
 63-19
80ZV Check & Adjustment Electrical Group
Electrical Circuit Check

Transmission trimmer plug solenoid valve electrical circuit check

- Problems and causes of trimmer plug solenoid valve
malfunction and abnormal clutch oil pressure
Clutch switching Clutch switching complete
Clutch oil pressure (MPa)
ON Cause Several Problem
Clutch Just after clutch
seconds after
solenoid valve OFF switching
switching
A shock will be
Disconnected
applied to the
ON cable or stick- 1.3~1.5
machine when
ing valve at (13~15 kgf/cm2)
the speed or
non-energized (185~213 psi)
direction is
Trimmer plug OFF position
changed.
solenoid valve
Sticking valve Approx. 0.4 No power
Sticking in non-excited status
at energized (4 kgf/cm2) Clutch
t0 t1 position (57 psi) slippage
1.3~1.5 MPa
(13~15 kgf/cm2)
(185~213 psi) Note
(Engine middle The same problems occur when the clutch pressure
speed) regulator valve is sticking. Therefore, if the solenoid
Normal
valve is not defective, check the regulator valve.
Pressure
Approx. 0.4 MPa Low pressure condition can also be caused by debris
(4 kgf/cm2) Sticking
(57 psi) at excited status (like o-ring pieces or gasket pieces) sticking in the sole-
noid valve.
Approx. 1.2 sec

85ZV63001

Manual operation button

80ZVE63008
63-20
80ZV Check & Adjustment Electrical Group
Electrical Circuit Check

<Step 1> Checking solenoid valve

- Measuring coil resistance

Disconnect the connector from the solenoid valve,

and then measure the coil resistance using a tester.
Note that a diode is incorporated in the coil.

Coil resistance Judgment

Approx. 27 Normal
Disconnect or shorted 0 Abnormal

- Checking valve for sticking

Be sure engine is off before checking.

Push the manual operation knob to the ON position

by hand, and then check that the spool operates
smoothly. If it does not operate smoothly, judge that
the valve is sticking. Disassemble, clean, inspect
and reassemble and retest the solenoid valve.

<Solution>

If the coil is disconnected or the valve is sticking,

replace the defective unit as an assembly.

WARNING
Unexpected movement of the machine may cause an
accident resulting in injury or death.
Be sure to observe the following items before starting
work.
- Position the machine on level ground, and lower
the bucket onto the ground.
- Block the tires with chocks to prevent them from
moving.
 63-21
80ZV Check & Adjustment Electrical Group
Electrical Circuit Check

<Step 2> Checking output circuit and cable Checking positive cable

Terminals to be checked Voltage Judgment

Solenoid valve
Between terminals LP and Approx. 24 V Normal
Control body grounding
D F: For forward clutch (For D trimmer solenoid) Approx. 0 V Abnormal
valve R: For reverse clutch
1: For 1st speed clutch
4 1 2: For 2nd speed clutch Checking negative cable
3: For 3rd speed clutch
F 4: For 4th speed clutch
D: For trimmer plug Terminals to be checked Voltage Judgment

3 R 2 Between terminals LB and Approx. 1 V Normal

body grounding
(For D trimmer solenoid) Approx. 24 V Abnormal

LP LB J7
- + H206 H205
<Solution>
2 1

If the voltage is abnormal, judge that the cable is discon-

H2
nected or broken. In this case, check the next connector
(H2 shown in the figure), and find the defective unit.
Repair or replace the defective unit.
T/M controller OUTPUT
(see “abbreviation chart” page 62-22)
A B AC EP TT WT BZ NL W

F R 1 2 3 4 D NR RR X COM

LR LBr LY LG LO LW LP SbP LB LgW LB

H208 H207 A511 A510 H203 A508 H206 F703 F803 F003 A512
H201 H202 A509 H204 H205
LP SbY LgL Gy GyL GyG LgBr GR GyB
A608 A306 A302 A307 A301 A308 G602 A501 A616

11 1

E2

Cable color
(+) ( )
F LR
R LBr
1 LY
2 LG LB
3 LO
4 LW
D LP
80ZVE63009

Disconnect the J7 connector from the trimmer plug, and

set the starter switch to the ON position.

Measure the voltage of the connector terminal on the

cable side using a tester. Note that the voltage reading
occurs for 1-2 seconds just after shifting the shift lever.

IMPORTANT
When measuring voltage, do not shortcircuit two ter-
minals of a connector. This is because the electronic
parts inside the controller may be damaged.
63-22
80ZV Check & Adjustment Electrical Group
Electrical Circuit Check

Neutral relay electrical circuit <Step 1> Checking cable of output circuit
check 1. Disconnect connector F7 from the neutral relay,
and then set the starter switch to the ON position.
NEUTRAL Set the shift lever to the neutral (N) position, and
RELAY then measure the voltage of the connector terminal
on the cable side.

2. Checking positive cable

RL SbP
+ +
H116 E215
Terminals to be checked Voltage Judgment
G L
D102 D110
Between terminals L and Approx. 24 V Normal
2 1
(BLACK) body grounding Approx. 0 V Abnormal
F7

3. Checking negative cable

G - From fuse F14 (starter switch terminal C)
Terminals to be checked Voltage Judgment
RL - To magnetic switch terminal Approx. 24 V Normal
Between terminals SbP and
body grounding Approx. 1 V Abnormal
SbP - to T/M controller

L - To Fuse F5 80ZVE63010 <Solution>

- Problem If the voltage is abnormal, judge that the cable is discon-

Engine does not start with the shift lever in neutral nected or shortcircuited. Repair or replace the cable.
position.

Though the transmission controller "N" LED indicator <Step 2> Checking neutral relay individually
is on, the engine will not start, judge that the neutral
relay contact is not closed. The neutral relay is the same type as the back-up lamp
relay, horn relay, etc. Therefore, to check the neutral
- Problem relay, replace it with one of these relays, then detect
The engine will start at the shift lever forward or which one between the neutral relay and the wiring is
reverse position. the cause of the fault.

If the engine starts though the transmission control- <Solution>

ler "N" LED indicator is off, judge that the neutral
relay contact is sticking, or the transmission control- If the relay is defective, replace it.
ler is defective.
 63-23
80ZV Check & Adjustment Electrical Group
Electrical Circuit Check

Parking brake electrical circuit - Problem

The parking brake cannot be applied or cannot be
check released.

The parking switch is interlocked to the parking lamp

of the instrument panel. It turns on and off the park-
ing lamp. If the lamp turns on when the switch is
pulled up and goes off when it is pushed in the
switch is working properly. If the lamp does not work
Parking S/W T/M controller INPUT
(see “abbreviation chart” page 62-22) the switch, lamp or wiring is defective. If the lamp
L
G
Y
works with the switch, check the parking brake sole-
R F R 1 2 3 A P I G +
B
noid or its wiring.
E SS AC EP TT WT EA BP S

B Y R
B Y LgL Gy GyL GyG WL SbY YL

WARNING
L G H703 H103 H135 H134 H115 H107 H708 G101

GO BY LR LBr LY LG LO LW GO LLg BY/Y L

E105 E102 B409 B408 B403 B402 B401 B406 B306 A102

LgG SbW
H707 A507
B 11
B304 D110
1
Unexpected movement of the machine may cause an
B405 H701
3 1 E1 B407
C701
accident resulting in injury or death.
G102
B3 H709 To prevent such an accident, observe the following
items before checking the parking brake circuit:
H7 - Park the machine on level ground.
- Block the tires with chocks to prevent wheels from
moving.
M1
(24V) (0~1V)
2 1
L LgG
H701 H707

B W
<Step 1> Checking cable of output circuit

[Step 1] Disconnect the connector from the solenoid valve, and

Parking brake switch OFF then measure the voltage of the connector terminal on
B
the cable side using a tester. Note that the starter switch
should be "ON", engine "OFF" and parking switch
W
should be at the OFF position.

Checking positive cable

[Step 2] Terminals to be checked Voltage Judgment

Parking solenoid Coil resistance
Between terminals LgG and Approx. 24 V Normal
body grounding Approx. 0 V Abnormal

Checking negative cable

Terminals to be checked Voltage Judgment

80ZVE63012
Between terminals L and Approx. 0 V Normal
body grounding Other than 0 V Abnormal

<Solution>

If a cable is disconnected or a wire broken, measure the

voltage of the next connector in the same way. Find the
defective cable, and then repair or replace the cable.
63-24
80ZV Check & Adjustment Electrical Group
Electrical Circuit Check

<Step 2> Checking solenoid valve - Measuring coil resistance

Screen board Disconnect the connector from the solenoid valves,

and then measure the resistance of the coil using an
analog meter.

Coil resistance Judgment

Front
Approx. 35 Normal
Disconnect or shortcircuited 0 Abnormal
Park brake
solenoid valve
Rear chassis (RH)
Note
The diode is incorporated in the coil.

- Checking sticking of solenoid valve

(S/N 5001~5050) K80ZV52007

Screen board
Run engine and charge the brake accumulator,
move the manual operation knob on the solenoid
valve, then check whether the parking brake can be
turned on and off. If the parking brake cannot be
Front turned on and off, the solenoid valve is stuck.

<Solution>

Rear chassis (RH) If wire breakage or a sticking valve is detected in the

Park brake
coil, replace the valve assembly.
solenoid valve

(S/N 5051~) K80ZV52008

 63-25
80ZV Check & Adjustment Electrical Group
Electrical Circuit Check

Gauge circuit electrical circuit <Step 1> Checking sensor signal

check Disconnect the connector A4 from the instrument panel,
or disconnect the connector from the corresponding
sensor.
Measure the resistance between the sensor signal ter-
INSTRUMENT PANEL minal and the ground terminal.
(see “abbreviation chart” page 62-22) If the measurement value is acceptable compared with
+ ES DD EG2 EG1 EG3 SS WTM TTM the standard value shown below, the sensor is not
(+) FM GND
defective.
RB
F604
YBr
H125
B
Ground If the measurement value is abnormal, check the wire in
Lg O O
D103 B901 B902
YB YSb
H105 H114
addition to the sensor because the cable may be defec-
Fuel level 10 1 tive (corroded, broken, or high resistance).
A4 T/M oil temperature
E/G water temp.
Torque converter oil temperature and engine water
H1
temperature

J8 Temperature of 60 80 100 120

1 2
detection area (ºC) (140 ºF) (176 ºF) (212 ºF) (248 ºF)
T/M oil E/G water
YBr B
H125 temp. sensor temp. sensor Resistance
between terminal 56.3 29.5 16.5 10
and body ( )
Y B

Fuel level sensor

H114
YSb

YB
H105

Fuel level Full 1/2 1/4 Empty

M5 M6

Fuel level sensor

80ZV63002 Resistance between
10 +1.0
- 0.5 (32) 49.5±4 85 +100
two terminals ( )

The sensors detect the fuel level, torque converter oil

temperature and engine water temperature and then Note
convert them into electric signals. The electric signals Figure in ( ) is for the reference resistance, at 1/2 way
are then fed to the respective gauges and indicated on position in sweep.
the gauges. If a gauge indicates wrong values, either
the sensor, gauge or wiring will be defective. Determine
the defective unit by using the following procedure.
63-26
80ZV Check & Adjustment Electrical Group
Electrical Circuit Check

<Step 2> Checking gauge Resistance between gauge terminals ( )

Engine water T/C, T/M oil
Gauge Fuel level
temperature temperature
Between S and E 120~125 75~80 115~120
Between S and V 120~125 85~90 115~120
Controller
Between E and V 170~190 130~150 165~170

Remove the instrument panel, and then disconnect the

Grounding S Power supply connector from the panel. Measure the resistance
24V
between the screw terminals on the rear surface of the
E V 15V panel. Judge whether the resistance value is accept-
able.

Viewed from rear surface of instrument panel Note

K90ZV62016
If a gauge is removed from the panel, the resistance
between the terminals will differ from the standard value
shown in the table. Please see table at bottom of page.
Instrument panel (back side view)

CN4
CN1 L13 CN3
1 4 L11 29 48
L12
8P L20 12P 16P
L1 58 57
5 8 L14 L10 35 56
Hour L10 L10
L2 meter
L10 L15 S
L21
L3
L16 E V
L4 S S
L17 L10
L5 E V E V
Fuel gauge Engine water temperature L18
sensor Tachometer
L6 L10 L10
L19
L7 S
CN2
L8 9 18 L22 L23 L24 L25 L26 L27
E V 20P
Transmission oil
L9 temperature sensor 19 28

90ZV63008

Resistance between gauge terminals ( )

Between S and E 160
Between S and V 150
Between E and V 310

S
Note
E V When the ground of the gauge is defective such as con-
tact failure and derailment, the pointer scales out.
Before replacing the gauge, check the ground circuit.
Viewed from rear surface of gauge

70ZV63014
 63-27
80ZV Check & Adjustment Electrical Group
Electrical Circuit Check

Bucket positioner electrical circuit check

<Step 1> Checking proximity switch
Detection part

Operation indicator lamp (LED) 1(Br) Supply +24 V to pin 1 (Br) and pin 2 (B), and connect
Detected View Z
the ground to pin 3 (L).
object

3(L) 2(B) If the operation indicator lamp (LED) does not light,
judge that the proximity switch is defective.

Proximity switch +24V

<Solution>
LED Br 1
Switch Coil for detent
main. B 2 inside Replace the proximity switch.
circuit L pilot valve
3
+24V
90ZV63009

<Step 2> Checking cable at chassis side

Though the clearance between the proximity switch and
Check the cable from the proximity switch to the pilot
the rod (detecting element) is 5±2 mm (0.197±0.079 in),
valve detent magnet solenoid in order. If wire discon-
the operation indicator lamp (LED) is not lit, judge that
nection is found, repair it.
the proximity switch is defective, or the cable at the
chassis side is disconnected or a wire broken.
63-28
80ZV Check & Adjustment Electrical Group
Electrical Circuit Check

<Step 3> Checking detent magnet solenoid

(S/N 80C4-5001~5270) (S/N 80C4-5271~)

Detent magnet
solenoid

Push rod

Detent solenoid

Fixing disc

Coupler To
tank port
K90ZV62013

From
pump
port

To / from MCV oil packs

70ZV63016

Check the continuity between coupler pins for the pilot

valve detent magnet solenoid.

If wire breakage is detected, repair it.

Detent coil specification

Coupler
(blue, female)
Rated voltage DC 24 V
Resistance 238
T

K90ZV63001

Voltage DC 24 V
Coil resistance 62±3