JLG 3394RT Service Maintenance Manual page 40

SECTION 3 - CHASSIS & SCISSOR ARMS
3. Both axis' raw angles need to be within ±5.0°, other-
wise the machine is to unlevel and the software will
prohibit calibration. Should this occur, attempt to
dissect the three areas of error to find the primary
contributor:
a. Machine mounting and/or grade:
With a digital level, measure the top of the
Ground Control box for levelness. If unable to
get a good reading, check the box's mounting
surface for levelness.
1
1. Ground Control Box
b. Tilt sensor mounting on machine or wedged
crooked in control box:
If the machine mounting/grade appears accept-
able, open the Ground Control box carefully.
Observe whether the tilt sensor is properly
seated.
2
1
1. Ground Control Box
3-4
2
2. Digital Level
2. Tilt Sensor
– JLG Sizzor –
c. Tilt sensor has developed an offset shift:
Remove the tilt sensor from the Ground Control
box, but keep both the tilt sensor and Ground
Control box electrically connected. Level one
axis of the tilt sensor and observe the raw read-
ing (should be within ±2.0°). Do the same for the
other axis. If either axis is greater than ±2.0°,
replace the tilt sensor.
Some possible reasons that the tilt sensor will not cali-
brate are:
a. The surface the machine is sitting on is off level
by a few degrees (flat doesn't imply level; park-
ing lots are often not level).
b. The tilt sensor has failed one or both of the
channels (X axis and Y axis).
c. Tilt sensor has moisture intrusion that has
shifted its output.
d. Water and/or corrosion in the box has corrupted
electrical connections or caused a tilt sensor or
ground control board failure (observe any
cracks in the box).
e. The Ground Control Box, as mounted on the
machine, does not allow the tilt sensor to be
level.
For the following troubleshooting steps, a bubble level
(smaller is better) will be needed and the machine must
be on a level surface:
1. On the Analyzer, go to Diagnostics/System and read
the tilt angle. If either angle reports +20.0°, there is
an electrical/electronic failure (tilt sensor, control
board, electrical connections).
a. Open the Ground Control Box.
b. Disconnect the sensor and clean any corrosion
off of the tilt sensor and control board connec-
tions.
c. Reassemble and test. If fault persists, replace tilt
sensor.
2. If the Analyzer displays angles other than +20.0°,
attempt to calibrate. If machine will not calibrate,
note the reason displayed on Analyzer:
a. SENSOR FAILURE – tilt sensor internal fre-
quency is out of range (replace sensor).
b. NOT LEVEL - tilt sensor has either developed an
offset or it is to unlevel as mounted on the
machine.
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