Tower Envelope Encroached - Hydraulics Suspended; Tower Length Sensor Disagreement - JLG 1250AJP Troubleshooting Manual

SECTION 1 - FAULT DICTIONARY AND SELECTED TROUBLESHOOTING

1.304 TOWER ENVELOPE ENCROACHED - HYDRAULICS SUSPENDED

Flash Code: 0-0
Tower envelope encroached - hydraulics suspended. The system has detected a tower envelope violation and suspended
hydraulics to prevent further encroachment. Use the APU to telescope in or lift down inside the envelope. See 1.91 ENVE-
LOPE ENCROACHED - HYDRAULICS SUSPENDED on Pg. 73.

1.305 TOWER LENGTH SENSOR DISAGREEMENT

Flash Code: 8-4
Tower length sensor disagreement. The control system detected a difference between the #1 (top) and #2 (bottom) tower
boom length sensors. A difference greater than 2.0"was held for at least 2.0 seconds. The lengths are visible in ANALYZER
⇒ DIAGNOSTICS ⇒ BOOM SENSORS ⇒ TOWER LENGTH 1 SENSOR and TOWER LENGTH 2 SENSOR.
Note Pretest Instructions
1.305.1 Read fault log with analyzer
1.305.2
1.305.3 Disconnect cable at sensor
#1 (top) [X093].
1.305.4 Fully lower tower. Check this
by looking for marks on the
tower boom from the wear
pads to be hidden. ANA-
LYZER ⇒ DIAGNOSTICS ⇒
BOOM SENSORS
1.305.5
1.305.6 Turn on machine. Discon-
nect tower boom length sen-
sor #1 [X093].
1.305.7 Turn on machine. Discon-
nect BLAM J3 [X088].
1.305.8 Disconnect tower boom
length sensor #1 [X093].
Disconnect BLAM J3
[X088].
1.305.9 Remove tower boom length
sensor #1 (top) [X093].
Measure resistance from pin
A [X093.A.pin] to pin C
[X093.C.pin].
1-144
Test
Are there any tower length sensor value out of
range faults?
Examine the cables, tower boom length sen-
sors #1 [X093] and #2 [X094], and mount-
ing blocks. Is there any visible damage, loose
hardware, kinked or stuck cables, etc.? Or, are
there any corroded or wet electrical connec-
tions?
If sensor #1 (top) [X093] is unplugged at the
top tower boom length sensor connector
[X093], message TWR LENGTH SENSOR
ONE VALUE OUT OF RANGE LOW should
show in the fault log. If sensor 2 shows, the
wires are swapped. Are the wires swapped?
TOWER LENGTH 1 and TOWER LENGTH 2
should read approximately 305 inches. Do
they?
Is the sensor with bad reading sensor #1?
Measure voltage from socket A[X093].A.soc]
to socket B [X093.B.soc]. Does voltage read
5VDC?
Measure voltage from pin 7 [X088.7.pin] to
pin 9 [X088.9.pin]. Does voltage read about
5VDC?
Is there continuity from tower boom length
sensor #1 socket C [X093.C.soc] socket C to
BLAM J3 socket 8 [X088.8.soc]?
Have second person slowly walk cable out
and back completely. The sensor cable
extends 400 inches (33' 4"). (Do not allow
cable to retract in an uncontrolled or rapid
manner. This will break the sensor.) Does
resistance change smoothly and consistently
up to 5000 Ω ± 500 Ω and back?
1250AJP
Result Corrective Action
Yes Troubleshoot, fix and clear them first
No Go to step 1.305.2
Yes Tighten any loose hardware. Clean, repair or
replace any bad connections. Repair/replace
damaged items. Do not disassemble length sen-
sor.
No Go to step 1.305.3
Yes Connect the top tower boom length sensor con-
nector [X093] to sensor #1 (top) and the bottom
tower boom length sensor connector [X094] to
sensor #2 (bottom)
No Go to step 1.305.4
Yes Keep tower lowered and analyzer reading boom
sensors. Go to step 1.305.9
No Note sensor(s) with bad reading. Go to step
1.305.5
Yes Go to step 1.305.6
No Go to step 1.305.10
Yes Go to step 1.305.8
No Go to step 1.305.7
Yes Repair/replace harness between tower boom
length sensor #1 [X093] and BLAM J3 [X088]
No Replace BLAM
Yes Go to step 1.305.9
No Repair/replace harness between tower boom
length sensor #1 [X093] and BLAM J3 [X088]
Yes Go to step 1.305.13
No Replace tower boom length sensor #1 [X093]
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