Load Stability Indicator Approaching Tip-Over Envelope
What does MANITOU-LSI-ACTIVE mean?
The MANITOU-LSI-ACTIVE (Manitou) diesel fault code means: Load Stability Indicator Approaching Tip-Over Envelope. This is a serious severity code.
Common Symptoms
- Dashboard or RDC2 display shows LSI-ACTIVE warning with load zone indicator flashing red or amber
- Boom extend, lift, or crowd functions slow down or stop responding mid-movement
- Audible alarm sounds continuously while load is in current position
- Stability warning light illuminates on the instrument cluster LCD
- Boom movements toward more extended or higher positions are blocked by the controller
- Machine feels unusually light on the rear axle or rear wheels visibly lift slightly
- Operator cab display shows load percentage at or above 85-100 percent of rated capacity for the current reach
Probable Causes (Ranked by Likelihood)
- Load weight and boom reach combination exceeds the rated load chart for current boom angle and extension Very Likely
- Incorrect or missing counterweight configuration not matched to the active load chart in the TCON controller Likely
- Boom angle sensor (inclinometer) out of calibration, reporting incorrect boom elevation to the stability ECU Likely
- Boom extension sensor fault causing the controller to misread actual reach distance Possible
- Attachment weight not programmed into the TCON or incorrect attachment selected in the instrument cluster menu Possible
- Ground slope exceeds rated operating angle, shifting the machine center of gravity outside the safe envelope Possible
- Axle lock or stabilizer system not engaged when required for the current lift configuration Less Likely
Step-by-Step Diagnostic Procedure
Stop all boom movement immediately. Do not attempt to override or ignore this warning. Lower and retract the boom to the travel position before doing anything else.
Check the load chart placard inside the cab against the actual load weight, current boom angle, and extension length. Confirm you are within the rated capacity for that combination. If you do not know the load weight, stop and weigh it before continuing.
Inspect the attachment selection on the RDC2 display or instrument cluster LCD. Confirm the correct attachment type and weight are programmed. A forks-to-bucket switch without updating the controller will shift the stability calculation.
Verify counterweight is installed and matches the configuration the TCON expects. Check the machine dataplate and the active load chart setting in the MASTERTECH or RDC2 menu to confirm they match physical configuration.
Check ground conditions. The machine must be on firm, level ground within the slope rating shown on the dataplate (typically 5 degrees side slope maximum). Use a level or the built-in inclinometer display if available.
Connect Manitou MASTERTECH service software and read live sensor data from the boom angle sensor (inclinometer) and boom extension sensor. Confirm the values match a manual measurement of the boom. A sensor reading more than 2-3 degrees off from actual means recalibration or sensor replacement is needed.
If sensors read correctly and the load chart is not exceeded, check for active DTCs in the TCON or stability ECU module via MASTERTECH. A secondary sensor fault can trigger a conservative stability lock even when the physical load is within limits.
If all sensor values are correct, load chart is within limits, and ground is level, the warning may indicate a real marginal condition. Reduce load or reduce reach and retest. If LSI-ACTIVE clears with a lighter load or shorter reach, the original configuration was genuinely at or beyond the rated envelope.
Frequently Asked Questions
What does Manitou code LSI-ACTIVE mean?
It means the Load Stability Indicator on your telehandler has detected that the current combination of load weight, boom angle, and reach is at or approaching the tip-over boundary for your machine. The controller is doing its job and protecting you from a rollover. It is not a hardware failure by itself, but it is a serious operational warning you must act on immediately.
Can I keep operating the machine with LSI-ACTIVE showing?
Only in a limited sense. The TCON controller will typically restrict or block boom movements that would make the condition worse. You can and should move the boom back to a safer position, lower load height, or retract toward the mast. You cannot safely continue the lift you were attempting without correcting the load, reach, or configuration first.
How much does it cost to fix?
If this is a genuine overload or wrong attachment setup, fixing it costs nothing except adjusting your operation. If a boom angle sensor or extension sensor is out of calibration, a dealer tech can often recalibrate through MASTERTECH at a cost of one to two hours of labor. If a sensor has failed, expect $150-$400 in parts plus labor, putting total repair cost between $400 and $1,200 depending on your dealer rate.
Will LSI-ACTIVE clear on its own when I lower the boom?
Yes, in most cases. If the warning is triggered by a real load-and-reach condition, returning the boom to the travel position or reducing the load will clear the active warning. If it does not clear after the boom is fully retracted and lowered with no load attached, you likely have a sensor fault or TCON configuration issue that needs a technician with Manitou MASTERTECH to diagnose.