JLG Articulating Boom Lift 85 Fault Code: Reference Voltage 4
Also called Load Pin Force Too Low Over Main Angle Change, Load Pin Force Too Low Over Main Length Transition, Load Pin Force Too Low Over Tower Angle Change, Load Pin Force Values Not Changing, Load Pin Horizontal Force Out of Range, Load Pin Sensor Fault, Load Pin Vertical Force Out of Range, Load Pin/Tower Lift Cylinder Angle Disagreement, New Load Pin Detected Fault, Problems with the Moment or Load Pin System
Reference Voltage 4 · ai-assisted, editor-reviewed · Last updated 2026-07-13
TL;DR
Fault code 85 covers a group of load pin (moment pin) system faults on JLG articulating boom lifts, including force out of range, sensor faults, force values not changing, and load pin/tower cylinder angle disagreement. It means the controller can no longer trust the load sensing system that helps prevent overload conditions.
High severity. This fault affects the load sensing system used to detect overload conditions. The machine may restrict function or operate with an unverified load reading until the fault is cleared and the load pin is recalibrated.
What does JLG Articulating Boom Lift error code 85 mean?
Fault code 85 is a grouped code covering several related problems with the load pin (also called the moment pin), which measures horizontal and vertical force to help the machine judge boom loading. When the controller cannot get valid, changing, or in-range force data from this sensor, it sets fault 85 and flags the specific underlying condition in the fault log.
The specific conditions covered under this code include horizontal or vertical force out of range, the load pin reporting its own internal sensor fault, force values not changing when they should, a new load pin being detected that does not match the one used during calibration, and a disagreement between the load pin force angle and the tower lift cylinder angle sensor.
Because this code invalidates the current load pin calibration in several of its triggering conditions, the machine's overload protection can no longer be relied on until the pin is recalibrated. This is why JLG ties several of these conditions directly to the boom sensor calibration procedure.
What triggers a JLG Articulating Boom Lift 85 code?
Several distinct set-conditions apply depending on which underlying fault is active: tower lift commanded for at least 2 seconds, not lifting down below elevation, with the load pin failing to report x and y force changes of at least 100 pounds per 3 degrees of tower lift cylinder angle change, occurring slower than 0.5 seconds (the y force check is ignored if the greater tower inclinometer angle is between 15 degrees and 50 degrees). A separate condition sets when force magnitude is greater than 50000 pounds and the load pin force vector angle disagrees with the tower lift cylinder angle sensor by 20 degrees for 5 seconds. Another condition sets when the tower is above elevation and force magnitude stays below 5000 pounds for more than 45 degrees of net main lift movement while the main boom angle referenced to gravity is not between +15 degrees and -15 degrees.
Common causes of 85
- A problem with the load pin itself or its mounting hardware
- A faulty or miswired tower lift cylinder angle sensor
- A newly installed or swapped load pin that does not match the one used for the last calibration
- Loss of valid load pin calibration due to one of the underlying fault conditions being triggered
- An internal sensor fault reported directly by the load pin electronics
How to troubleshoot JLG Articulating Boom Lift 85: first checks
- Check the fault log for the specific underlying fault (force too low over main angle change, force too low over main length transition, force too low over tower angle change, force values not changing, load pin not calibrated, or load pin/tower lift cylinder angle disagreement) since code 85 is a grouped notification
- Inspect the load pin mounting for looseness, damage, or signs it has been recently replaced
- Inspect the load pin wiring and connectors for corrosion, damage, or loose pins
- Check for other load pin or cylinder angle faults logged around the same time, as JLG notes these often occur together
- Verify whether a new or different load pin is installed compared to the one used during the last calibration
How the code clears
Because several of the underlying conditions explicitly invalidate the current load pin calibration, the boom sensor calibration procedure must be performed after resolving the mechanical or wiring issue. No separate clearing step is listed beyond addressing the root cause and recalibrating.
Frequently asked questions
What does JLG fault code 85 mean?
It is a grouped fault covering multiple load pin (moment pin) system problems, including force readings out of range, sensor faults, force values not changing, and disagreement between the load pin and tower lift cylinder angle sensor.
Will fault code 85 stop the boom lift from working?
The load pin is part of the overload protection system, so once this fault sets, the machine may restrict lift functions or operate without reliable overload sensing until the issue is fixed and the pin is recalibrated.
Do I need to recalibrate after fixing fault 85?
Yes, in most of the underlying conditions the current load pin calibration is invalidated, so the boom sensor calibration procedure needs to be run after the mechanical or electrical issue is corrected.
Why does the fault log show a different description than 'fault code 85'?
Code 85 is a parent grouping. JLG lists several distinct triggering descriptions such as force too low over main angle change or load pin/tower lift cylinder angle disagreement, and the fault log will show the specific one that occurred.
Can a new load pin trigger this fault?
Yes. If a load pin is detected that is different from the one used during the last calibration, the controller sets a new load pin detected fault under this code.
What should I check first if this fault appears?
Start with the fault log to identify the specific underlying condition, then inspect the load pin mounting and wiring, and check the tower lift cylinder angle sensor if a disagreement fault is logged.