JLG Articulating Boom Lift 25 Fault Code: A Function is Prevented Due to a Cutout
Also called Backup BLAM Communications Active, Boom Prevented - Drive Selected, CAN Dongle Attached - Hydraulics Not Restricted, Disconnect Analyzer and Cycle EMS to Perform Boom Retrieval, Drive Prevented - Above Elevation, Drive Prevented - Boom Selected, Drive Prevented - Tilted & Above Elevation, Function Prevented Due to a Cutout, Function is Prevented Due to a Cutout, Functions Locked Out - BLAM Module Software Version Improper, Functions Locked Out - Chassis Module Software Version Improper, Functions Locked Out - Platform Module Software Version Improper, Generator Motion Cutout Active, Jib Swing Prevented - In 1000 Pound Mode, Manifold Surface Temperature (MST) High Voltage, Model Changed - Hydraulics Suspended - Cycle Emergency Stop Switch
A Function is Prevented Due to a Cutout · ai-assisted, editor-reviewed · Last updated 2026-07-13
TL;DR
JLG code 25 is a priority-level fault covering a group of cutout and lockout conditions: boom or drive functions being blocked by configured cutout logic, tilt/elevation cutouts, UMS sensor limit or range faults, tilt module communication loss, model change lockouts, and module software version mismatches. It is not a single wiring fault, it is a status message telling the operator why a function will not respond.
Medium severity. Most code 25 messages are informational cutout notices telling the operator why a function is blocked, but the tilt module failure and UMS out-of-range conditions point to a sensor or module problem that affects tip-over protection and should be checked before continued operation on slopes or elevation.
What does JLG Articulating Boom Lift error code 25 mean?
Code 25 is reported at priority level (4) or (11) depending on which specific message is active, and it represents a family of related messages rather than one fault. Most of them describe intentional cutouts: the machine's controller is configured to prevent certain combinations of drive and boom motion, or to prevent drive above a set elevation or when tilted, and the operator has selected a function that conflicts with that configuration.
Other messages under this code relate to the Upper Mast Structure (UMS) sensor, which is used to compare boom angle to the turntable. If the UMS sensor reads beyond its usable angle limits, or disagrees with the turntable tilt sensor by more than the allowed range, the controller reports it here.
The remaining group of messages covers system-level lockouts: a tilt or positrac module that has stopped communicating, a model number change that requires a power cycle before hydraulics will work again, backup communication links being used with the BLAM module, or a software version mismatch between the ground module and the platform, chassis, or BLAM module.
Common causes of 25
- Drive cutout configured to prevent simultaneous drive and boom operation, triggered when a drive function is selected while a boom function is active, or vice versa
- Drive cutout configured to prevent drive above a set elevation, triggered when drive is selected while the boom is above that elevation
- Tilt configured to cut out drive, triggered when drive is selected while the machine is tilted and above elevation
- Function cutout active and configured to block boom functions only, or to block both drive and boom functions
- UMS sensor backward limit reached, when upright angle relative to the turntable exceeds +2.5°
- UMS sensor forward limit reached, when upright angle relative to the turntable is less than -4.0°
- UMS sensor out of usable range, when both the turntable tilt sensor and UMS sensor read greater than ±10° in the same direction
- Tilt or positrac module not communicating, causing the controller to default to a massively tilted state without preventing vehicle roll on grade
- Drive prevented because the charger is connected and drive cutout is active
- Model number changed through the analyzer, suspending hydraulics until power is cycled
- Backup RS232 communications link to the BLAM module active, especially with an analyzer still connected
- Software version mismatch between the ground module and the platform, chassis, or BLAM module
How to troubleshoot JLG Articulating Boom Lift 25: first checks
- Identify the exact message text shown on the analyzer or display, since code 25 covers many distinct conditions and the fix depends on which one is active
- If a boom or drive function is being blocked, check whether another function is currently selected at the same time and whether the machine is above its configured elevation or tilted, since these are normal cutouts by design
- Check the UMS sensor and turntable tilt sensor readings and wiring connections if the fault reports a UMS limit or out-of-range condition, since sensor misalignment or a bad connection can cause false angle readings
- Check communication wiring and connectors to the tilt/positrac module if a module failure or not-communicating message is shown, since the controller will default to an unsafe tilted assumption without correcting it
- If the message indicates a model change or backup BLAM communications, disconnect the analyzer and cycle the emergency stop switch or main power as instructed by the on-screen text
- Verify software versions on the ground, platform, chassis, and BLAM modules match if a lockout for improper software version is reported
How the code clears
No single reset procedure applies to all code 25 messages since they cover different conditions. For model change or backup BLAM communications messages, the machine explicitly instructs the operator to disconnect the analyzer and cycle the Emergency Stop switch or power before hydraulics will resume. For cutout messages tied to drive/boom selection, elevation, or tilt, the message clears automatically once the conflicting function is deselected or the machine is brought back within the configured limits. No separate clearing step is listed for the UMS sensor limit, sensor range, or module software mismatch messages beyond correcting the underlying sensor or software issue.
Frequently asked questions
What does JLG fault code 25 mean?
It is a general cutout and lockout code that covers many separate messages, including boom or drive functions being blocked by cutout configuration, tilt or elevation limits, UMS sensor faults, module communication problems, and software version mismatches. The exact meaning depends on which specific message text is displayed.
Why is my JLG boom lift preventing drive or boom function with code 25?
The machine's cutout configuration is designed to prevent certain combinations, such as driving while a boom function is selected, driving above a set elevation, or driving while tilted and above elevation. This is normal protective behavior, not necessarily a malfunction.
What is the UMS sensor and why does it matter for code 25?
The UMS sensor measures the upright angle relative to the turntable. If that angle goes beyond +2.5° backward or -4.0° forward, or disagrees with the turntable tilt sensor by more than ±10° in the same direction, the controller reports a UMS-related fault under code 25 because it can no longer trust the boom position reading.
Why does my machine say hydraulics are suspended after a model change?
Changing the model number through the analyzer suspends the hydraulic system as a safety precaution. Power must be cycled using the Emergency Stop switch before hydraulic functions will work again.
Is code 25 dangerous to keep operating with?
Most code 25 cutout messages are protective and expected. However, a tilt module communication failure is more serious because the controller defaults to assuming a heavy tilt without actively preventing vehicle roll on a grade, so that specific message should be addressed before working on slopes.
Can code 25 be caused by a software mismatch between modules?
Yes. If the major software version of the platform, chassis, or BLAM module does not match the ground module, the controller locks out functions and reports it under code 25 until the versions are corrected.