JLG 1250AJP Service Manual - Manual (Page 437)

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 cal-
ibration 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 calibration, no external tools are required to com-
plete the calibration 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 excep-
tion of the load control calibration, all calibrations are
accessed by connecting the analyzer into the control sys-
tem inside the main terminal box or on the bottom of the
platform control box. Calibration of the platform load sens-
ing 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
Calibration 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
replacement
Load pin removal or replacement
Main boom angle sensor removal or replace-
ment
Any boom sensor calibration faults
Boom control system inaccuracies
Platform Load Sensing Sys-
tem Calibration EIM module replacement
Load cell removal or replacement
Load control inaccuracy