Service Manual Instruction Manual

SECTION 6 - JLG CONTROL SYSTEM
6-58 – JLG Lift – 3121171
2. After the pressing the ENTER key , the analyzer will
display “CALIBRATING…”on the bottom line and Control
System will record left tower angle 3, right tower angle
3, and chassis tilt sensor values. The Control System
must see a change in the drive orientation switch or
“CAL FAILED” and “DRIVE ORNT SW” will be displayed. If
the change in right sensor readings is more than 1.0
from the change in left sensor readings, “CAL FAILED”
and “TWR ANGL FAILED” will be displayed. The control
system establishes the ground slope in relation to the
boom using the 4 tower boom angle sensor readings
before and after rotation. Ground Slope Left angle sen-
sor = (left 2-left 3)/2; Ground Slope Right angle sensor =
(right 2-right 3)/2. The Control system establishes the
low tower angle calibration point per sensor by taking
the difference between the angle 3 and the ground
slope in the direction of the boom. Low Tower Angle
Calibration value = -3.8 +/- Ground Slope. The chassis tilt
calibration is calculated as in the chassis tilt calibration
procedure. The chassis tilt calibration will be established
here and in the separate chassis tilt procedure. If the
chassis tilt reads more than 1.75 the Control System will
keep the chassis tilt calibration data and the analyzer
will display “CAL FAILED” and “TILT CAL FAULT”.
Step 4 - Position 4
1. After completing the previous step, the analyzer will
read:
The Control System will disable all functions except auto
platform level and tower lift up.
Operate the Lift tower function.
2. Once the Tower Boom lifts such that the Tower Boom
Angle reads greater then 25 degrees, Tower Lift Up will
be suspended and the analyzer will display “CHECKING
BOOM…”
3. Once “CHECKING BOOM…” is started the control system
will wait 2 seconds and then capture the position of the
Main Boom to Tower, Tower Cylinder Angle and Tower
Length. The control system will then command the Main
Lift, Tower Lift and Tower Telescope PVG valves to 40%,
engage the Main Control and PVG enable valves and
command the Engine to 1800 RPM for 20 seconds. The
control system will monitor for the Main Lift angle
increasing by more then 0.2 deg, Tower Lift angle
increasing by more than 0.2 deg and the Tower Tele-
scope length increasing by more than 0.5" (1.3 cm). If
one of these conditions occur the test will abort and dis-
play on the top line “CHECK FAILED:” and “MN LIFT
ENABLE”, “TWR LIFT ENABLE” or “TWR TELE ENABLE” on
the bottom line depending on which section moved.
After the 20 seconds has elapsed the control system will
command the engine back to idle, shut off the com-
mands to the PVG valves, disengage the Main Control
and PVG enable valves and Turn On the Main Lift, Tower
Lift and Tower Telescope Enable valves and monitor the
Main Lift angle for decreasing movement of more than
0.2 deg, Tower Lift angle for decreasing movement of
more than 0.2 deg and Tower Telescope length decreas-
ing movement of more than 0.5" (1.27 cm) for 60 sec-
onds. If one of these conditions occur the test will abort
and display on the top line “CHECK FAILED:” and “MAIN
LIFT HOLD”, “TOWER LIFT HOLD” or “TOWER TELE HOLD”
on the bottom line depending on which section moved.
After the 60 seconds has elapsed the control system will
leave the enable valves on and turn on the Main Control
Valve and turn on the Tower Lift PVG valve at a 20%
down command and monitor the Main Lift angle for