JLG DVSP Series Service Manual - Manual (Page 134)

SECTION 6 - TROUBLESHOOTING
6-20 – JLG Lift – 3121136
Code 21 - Beacon - Disconnected
Check For These Obvious Conditions First:
• Is machine equipped with flashing amber beacon light.
Code 22 - Horn - Short Circuit
Check For These Obvious Conditions First:
• Damaged wiring in the horn wiring harness or a damaged horn unit.
Table 6-24. Code 21 - Beacon - Short Disconnected
STEP ACTION SPEC YES NO
1. Is machine equipped with a flashing amber beacon light.
— Go to Step 3 Got to Step 2
2. At the Ground Control Module enter the programming mode, check
if the Beacon light open circuit detection is enabled.
— Disable It
Replace Ground
Control Module
3. Check voltage at the P1 connector on the Ground Control Module
between pin-12 and pin-5. Is reading within specification?
2 - 4 V DC
Replace Ground
Control Module
Go to Step 4
4. Remove the wire terminals at the beacon, check continuity of each
of the wires from pins-12 and 5 on the P1 connector to the beacon
end.
—
Replace the
Beacon
Repair or
Replace Wiring
Table 6-25. Code 22 - Horn - Short Circuit
STEP ACTION SPEC YES NO
1. At the Ground Control Module, P1 connector, check the voltage
across pins-14 and 7 to the horn. Is reading within specification?
0 - 2V DC Go to Step 2
Replace Ground
Control Module
2. Remove the wire terminals at the horn, check continuity of each of
the wires from pins-14 and 7 on the P1 connector to the horn end.
—
Replace the
Horn
Repair or
Replace Wiring