Service Manual Instruction Manual

SECTION 6 - JLG CONTROL SYSTEM
3121171 – JLG Lift – 6-5
6.3 CALIBRATION INSTRUCTIONS
This machine incorporates a variety of sensors and a high
degree of function interaction. For safety and proper machine
functionality, the calibration procedures must be repeated for
any control module replacement, system calibration related
fault, or removal or replacement of any sensors, valves, coils,
motors, or pumps. The chart below lists the calibrations
required and potential reasons for re-calibration.
All calibration procedures are menu driven through the use of
the standard JLG analyzer. With the exception of steering cali-
bration, no external tools are required to complete the calibra-
tion procedures. The user is prompted to exercise the machine
in a specific order to use the machines physical properties to
consistently establish sensor response and the interaction of
valves, pumps, and motors. Steering calibration also uses the
analyzer and is performed on one side of the machine at a
time requiring the use of a string or other means to determine
when the tires are in line with each other. With the exception
of the load control calibration, all calibrations are accessed by
connecting the analyzer into the control system inside the
main terminal box or on the bottom of the platform control
box. Calibration of the platform load sensing system is
accessed by connecting the analyzer directly into the EIM
module.
Table 6-2. Reasons for Re-Calibration
Calibration Procedure Reasons for Re-calibration
Steering Calibration Ground module replacement
Chassis module replacement
Steer sensor removal or replacement
Persistent wheel misalignment
Drive Calibration Ground module replacement
BLAM module replacement
Drive pump/coil replacement
Drive pulls to one side
Drive lugs engine
Poor slow speed control
Boom Valve Calibration Main lift valve/control module replacement
Tower lift valve/control module replacement
Tower telescope valve/control module replacement
Platform Level Crack Point Cali-
bration
Platform module replacement
Ground module replacement
Platform level valve/coil replacement
Erratic platform leveling
Chassis Tilt Calibration Ground module removal or replacement
Main terminal box removal or replacement
Tilt indication inaccuracy
Boom Sensors Calibration Ground module removal or replacement
BLAM module removal or replacement
Tower boom angle sensor removal or replacement
Tower boom length sensor removal or replacement
Tower lift cylinder angle sensor removal or replace-
ment
Load pin removal or replacement
Main boom angle sensor removal or replacement
Any boom sensor calibration faults
Boom control system inaccuracies
Platform Load Sensing System
Calibration
EIM module replacement
Load cell removal or replacement
Load control inaccuracy