Service Manual Instruction Manual

SECTION 6 - JLG CONTROL SYSTEM

3121171 – JLG Lift – 6-69

6. 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 then will 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 and Tower

Lift angles increasing by more then 0.2 deg and the

Tower Telescope length increasing by more then 0.5”. 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.