Failure Troubleshooting For The Field; Tilt Sensor Electrical Evaluation; Elevation Angle Sensor Electrical Evaluation - JLG 1930ES Service Maintenance Manual

SECTION 5 - JLG CONTROL SYSTEM
carefully. Observe whether the tilt sensor is prop-
erly seated.
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.
NOTE: Check that the tilt switch is properly set by referring
to the Tilt Settings table in section 1 of this manual.

Failure Troubleshooting for The Field

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 the 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. Take the Ground Control box off of the machine
and open.
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 won't calibrate, note
the reason displayed on Analyzer:
a. SENSOR FAILURE – tilt sensor internal fre-
quency is out of range (replace sensor).
5-6
b. NOT LEVEL - tilt sensor has either developed an
offset or it is too unlevel as mounted on the
machine.

5.3 TILT SENSOR ELECTRICAL EVALUATION

This basic check using the JLG Analyzer can be used to
test the Tilt Sensor.
• If angle measurements read +20.0, then a sensor/
wiring/connector fault exists. If the readings intermit-
tently display expected angles, then there is likely a
wiring/connector problem and not a failed sensor. In
either case, open the ES Ground box. Disconnect the
sensor, check the wire terminations, and clean any cor-
rosion on the tilt sensor and control board connec-
tions. Reconnect and test. If the fault persists, replace
the tilt sensor and return the faulty tilt sensor to JLG
with a detailed description of the diagnostic steps
taken.
5.4 ELEVATION ANGLE SENSOR ELECTRICAL
EVALUATION
These basic checks using the JLG Analyzer can be used
to test the Elevation Angle Sensor. If the problem is still
occurring, perform the Tilt vs. Allowed Height Evaluation
described below.
• On a level surface, with the Analyzer under DIAG-
NOSTICS/ELEV SENSOR, verify that the elevation
angle sensor voltage increases (ranges from 0.2V-
0.8V to 3.6V-4.2V) with platform height. If not, check
the sensor mounting. If necessary, unbolt sensor and
rotate by hand while monitoring with the Analyzer to
check the integrity of the sensor output.
• For machines equipped with an elevation proximity
switch, if the Elevation Sensor appears satisfactory,
verify that the Elevation Prox switch is opening and
closing appropriately by watching the change of state
between the stowed and elevated positions (monitor
PROX SWITCH under DIAGNOSTICS/ELEV SENSOR).
If a change of state is not observed, check prox mount-
ing and operability by placing metal in front of the prox
sensor face.
– JLG Lift– 3121166