Std Lever Troubleshooting; Mini Lever Or Joystick Troubleshooting - Toyota 8FGU15 Repair Manual

8 TROUBLESHOOTING
Phenomenon on
Control type
vehicle
4YE/1ZS engine
model
(STD lever)
When lifting a heavy
load, it is unable to
lift upward or lift
speed is slow, even
if rising engine
speed.
Travel and load
handling control
4YE/1ZS engine
model
(Mini lever or Joy
stick)
When lifting a heavy
load, it is unable to
lift upward or lift
speed is slow, even
if rising engine
speed.
Malfunction area
Checking method
and mode
▪ Lift raise switch
unit:
Open fault
(Switch mounted
incorrectly, in-
ternal damage,
stuck)
▪ Lift raise switch
ON/OFF check with
line:
analyzer
Disconnection
fault (Harness,
connector)
▪ Switch ground
line:
Disconnection
fault (Harness,
connector)
▪ Material hand-
ling lever poten-
tiometer unit:
Lever defect
Material handling
▪ Material hand-
lever potentiometer
ling lever line
voltage check:
(Power supply,
Move the lever into
signal, ground):
forward and reverse
Disconnection
positions and check
fault (Harness,
the voltage change.
connector)
Short or link fault
(Harness, con-
nector)
8-159
Corrective action
Harness check or re-
place switch
If there is no
change, perform a
harness check or re-
place the poten-
tiometer
8