Troubleshooting

TROUBLESHOOTING / Troubleshooting B
T5-6-2
RELATIONSHIP BETWEEN MACHINE
TROUBLE SYMPTOMS AND RELATED
PARTS
This table indicates the relationship between machine
trouble symptoms and the potential problem parts,
which may cause trouble if failed, and the evaluation
methods of these components.
Parts
Function
Symptoms in control sys-
tem when trouble occurs.
Symptoms in machine
operation when trouble
occurs.
Forward/Reverse Lever
• Sends the command signal
on Forward/Reverse to MC.
• Sends the signal on for-
ward/reverse to the neutral
relay.
• Keeps MC in neutral when
traveling.
• Although the forward/reverse
lever is operated, the ma-
chine does not travel.
• Although the forward/reverse
lever is in Reverse, the back-
light and back buzzer are not
operated.
Shift Switch
• Sends the command signal
on speed gear to MC.
• Particular speed gear only
can be operated according to
condition of the shorted or
open circuit.
• When the travel mode switch
is manually operated, the
machine can travel at par-
ticular speed gear only.
• When the travel mode switch
is automatically operated,
speed can be shifted to par-
ticular speed gear only.
Parking Brake Switch
• Releases/applies the parking
brake.
• The parking brake cannot be
released or applied.
• Although the parking brake
switch is OFF, the machine
cannot operate in the forward
or reverse direction.
• Although the parking brake
switch is ON on the slope,
the machine moves.
Travel Mode Selector
Switch
• Sends the command signal
on travel mode to MC.
• MC makes only the travel
mode in manual gear shifting
operable.
• When the automatic gear
shifting is selected, the ma-
chine can travel in the travel
mode in manual gear shifting
only.
Work Mode Selector
Switch
• Sends the command siganl
on work mode to MC.
• MC keeps the work mode
selector switch in Normal
mode.
• Although mode L has been
used, fuel consumption sud-
denly increases after certain
week or month.
• Machine operation may be
normal according to the
switch to reduce engine out-
put is controlled to low at low
speed gear.
Clutch Cut-Off Position
Switch
• Sends the command siganl
on clutch cut-off to MC.
• MC makes the clutch cut-off
mode disabled.
• Although mode S,N or D in
the clutch cut-off mode
switch is selected and the
brake pedal is depressed,
the clutch cut-off is not oper-
ated.
Down-Shift Switch
Down-Shift/Up-Shift
Switch
• Sends the command signal
on down-shift/up-shift switch
to MC. (The circuit in
down-shift switch is
connected to that at
down-shift side in
down-shift/up-shift switch.)
• MC makes
down-shift/up-shift switch
control disabled.
• Although the
down-shift/up-shift switch is
pushed, down-shift/up-shift is
not operated.
• Although the down-shift
switch is pushed, down-shift
is not operated.
Hold Switch
• Sends the command signal
on hold switch to MC.
• MC makes hold switch
control disabled.
• Although the auto spped
gear shifting is selected and
the hold switch is pushed,
travel speed gear is not fixed.