JLG Telehandler 2560 Fault Code: Function Prevented - Boom Retracted Sensor Faulty - Sensing Invalid

What does JLG Telehandler error code 2560 mean?

Code 2560 means the UGM controller has flagged the boom retracted sensor input, wired at J3-8, as giving an invalid or inconsistent reading. This sensor tells the machine whether the boom is fully retracted or not, which is a key input for the load stability indicator (LSI) and load moment indicator (LMI) systems on machines configured for LSI-CAN or LSI-CAN plus LMI.

When the fault sets, the controller stops trusting the boom retracted sensor and instead assumes the boom is always extended. This is a conservative fail-safe: treating the boom as extended is generally the more restrictive assumption for stability calculations. However, it means the machine no longer knows the true boom position, and that can affect available functions and load charts.

This is flagged as a machine system distress condition. The fault will stay active, or latched, until the machine is power cycled, even if the sensor signal appears to correct itself in the meantime.

What triggers a JLG Telehandler 2560 code?

The UGM sets code 2560 when it detects one of the following on a machine configured for LSI-CAN or LSI-CAN plus LMI: with no telescope function active, the boom retracted sensor state changes on its own; with telescope-in active, the sensor transitions from high to low; with telescope-out active, the sensor transitions from low to high; or with telescope-out active, the sensor fails to go high for 5 seconds while at least 950 mA is commanded to the function and the load moment warning point has been met or exceeded.

Common causes of 2560

• Faulty or failing boom retracted sensor that produces an inconsistent or invalid signal state
• Wiring or connector problem on the boom retracted sensor circuit at input J3-8, including corrosion, chafing, or a loose pin
• Sensor signal changing state unexpectedly while no telescope function is being commanded, suggesting a marginal or intermittent sensor
• Sensor not transitioning correctly (high to low or low to high) in step with telescope-in or telescope-out commands
• Sensor stuck low during telescope-out operation while the function is actively commanded and the load moment warning point has been reached, pointing to a sensor that has failed to respond or a mechanical target misalignment

How to troubleshoot JLG Telehandler 2560: first checks

1. 1Inspect the wiring and connector at input J3-8 for corrosion, moisture, loose pins, or chafed insulation
2. 2Check that the boom retracted sensor is securely mounted and properly aligned with its target, since a shifted sensor or target can cause invalid transitions
3. 3Cycle the telescope function in and out (with the machine in a safe, controlled condition) and observe whether the sensor state changes align with actual boom movement, if diagnostic tools allow you to view live sensor status
4. 4Verify the machine's configuration (LSI-CAN or LSI-CAN plus LMI) is correct, since this fault is specific to those configurations
5. 5Check for other faults or damage on the boom that could affect sensor triggering, such as debris or physical obstruction at the sensor location

How the code clears

This fault latches until the machine is power cycled. No separate clearing step is listed beyond cycling power, but power cycling will only clear the fault code, not the underlying sensor or wiring problem. If the sensor issue is not corrected, the fault is expected to set again during normal operation.