Hitachi ZW180, Technical Manual

Page: 80 / 374

SYSTEM / Control System
T2-1-38
Speed Shift Holding Control
Purpose: To hold the speed shift while towing or trav-
eling uphill.
Operation:
1. When the hold switch is pushed once, the signal is
transmitted to MC.
2. MC continues to transmit the signal to the speed
shift solenoid valve of each time, and after that,
the speed shift is fixed although if the accelerator
pedal or the brake pedal is depressed.
NOTE: The speed shift holding control is made
only when auto (1-4L, 2-4N, or 1-4H) of the
travel mode switch is selected.
3. MC releases the speed shift holding control in
case the following switches operations are made.
•
Turning the key switch OFF
•
Pushing the hold switch again
•
Downshift switch
•
Upshift switch
•
FNR lever
•
FNR selector switch (only when effective)
•
FNR switch (only when effective)
•
Speed shift switch
•
Travel mode switch
•
Parking brake switch
NOTE: The shift switch has two switches, and their
combination of ON varies depending on
each speed shift. The controller judges
which speed shift has been selected by the
combination of the two input signals.
NOTE: The FNR switch does not transmit the neu-
tral signal. In case of no electric current
from the FNR switch, the controller judges
that the switch is neutral (N).
NOTE: Each mode switch of the travel mode switch
is supplied with respectively different volt-
ages from the monitor unit, and if a switch is
selected, MC judges which mode has been
selected.