Subject: Why a JLG EC600SJP boom lift would do every function except drive, and what its safety interlocks were really trying to say.
Key Takeaways
In short
- A JLG EC600SJP boom lift can lift, swing, and telescope perfectly and still refuse to drive because its safety systems are blocking movement.
- Fault code 2211 “FSW INTERLOCK TRIPPED” points to the platform footswitch and to how long it is kept pressed without a function being used.
- The drive orientation system stops drive and steer when the boom is swung past the rear wheels until the operator confirms the true driving direction.
- Clear, simple explanations of terms like footswitch, stow position, jib, and drive orientation switch help operators work with the machine instead of fighting it.
Story & Details
A wet workday and a frozen machine
On a wet workday in 2025, an electric JLG EC600SJP boom lift stood on site with its platform controls shiny with droplets. The operator climbed into the basket, powered up the controls, and saw a message on the small display: “2211 FSW INTERLOCK TRIPPED.” The machine could raise and lower the boom, swing left and right, and telescope in and out. Yet when the operator tried to drive, nothing happened.
The situation felt unfair. In simple words, the operator reported that the machine did every function but would not move. The wheels stayed still as if the brakes were locked. Only the gentle whine of hydraulic movement from the upper structure showed that the machine was listening at all.
The code that pointed to the pedal
The number on the screen turned out to be more than a random fault. Technical manuals for JLG boom lifts explain that “FSW INTERLOCK TRIPPED” appears when the platform footswitch stays pressed for about seven seconds without any function being selected. The controller then assumes that the pedal is being held down by mistake and asks the operator to lift the foot, wait, and press again before continuing [2][3].
This makes sense in a quiet office. On a noisy, wet site it is less obvious. The footswitch looks like a simple pedal on the floor of the platform. To the control system it is a safety gate: no pedal, no motion. With water around the panel, heavy boots on the pedal, and boom functions already moving, it was easy to imagine that the pedal had been pressed a little too long, or that moisture was playing tricks with its signal.
Simple checks followed. The idea was to tap the pedal up and down, make sure nothing was stuck underneath, and cycle the power so the controller could forget the old fault. The fact that every boom function still worked suggested that the footswitch was not completely broken, but the code remained an important clue. It showed that the safety brain of the machine was paying close attention to how the operator’s foot behaved.
The mystery of the full rotation
The real turning point came later the same day. The operator explained that the boom lift had been rotated so that the upper structure was facing completely backwards. The turret had swung about 180 degrees relative to the normal driving position. In that orientation the machine simply refused to drive. When the turret was slowly brought back to its original forward position, drive returned.
This was not a random coincidence. It was a pattern. A technician who came to the site in the afternoon said that the situation could be solved by pressing a button and waiting for a signal three times. The operator did not know which button, or what kind of signal to expect, but there was no doubt that the rotation of the boom and the lack of drive were linked. There was also a subtle detail: the boom lift could sometimes drive even when the turret was not perfectly straight. The problem appeared only when rotation went beyond a certain angle.
That behaviour matches a feature built into many modern JLG boom lifts: the drive orientation system. When the boom is swung past the rear drive wheels, the system disables drive and steer and flashes a special indicator light. The idea is simple. When the boom is directly over the front axle, pushing the joystick forward makes the machine go in the same direction the operator expects. When the boom is rotated far to the side or over the back, “forward” on the joystick no longer matches the physical front of the chassis. To avoid accidents, the machine demands a clear confirmation from the operator before allowing the wheels to turn [1][3][4][6].
Finding the hidden orientation button
On the EC600SJP, this confirmation lives in a small button on the platform control box. It is marked with a tiny diagram of the chassis and an arrow that shows the real forward direction of travel. When the upper structure is swung past the rear wheels and the operator tries to drive, the drive orientation light should start to flash. The correct reaction is to press and release the orientation button, then move the drive joystick in the direction that matches the arrow.
If that sequence is done in time, an audible signal sounds and the light stops flashing. Drive and steer come back to life. If the joystick is not moved soon enough after the button press, the confirmation expires and the system demands another press. To someone hearing “press a button and wait for a signal three times” on a busy afternoon, this could easily feel like a mysterious ritual instead of a clear confirmation step.
The fact that the EC600SJP could still move when the turret was not fully rotated fits this picture. The system only cares when the boom has passed a defined zone near the rear of the machine. Within that zone, drive and steer are locked until the operator clearly states, through the orientation button and joystick movement, “yes, I know which way this machine will go.”
A simple question about one small word
In the middle of all this, one short question appeared: “jib?” The answer to that word helped tie the story together. The EC600SJP is a telescopic boom lift with a shorter boom section at the outer end of the main boom. This smaller section is called the jib. It can move up and down on its own and carries the platform at its tip [1].
When instructions talk about stowing the jib, they mean folding this small outer boom into a compact, transport-safe angle. When instructions talk about stowing the boom as a whole, they mean lowering and retracting the main boom, folding the jib, and aligning the upper structure so that the platform and boom are lying neatly over the chassis, ready for travel or storage.
Understanding these words turns a confusing panel into a readable story. The FSW interlock code points to the footswitch and to how long it is held down. The lack of drive with the boom rotated 180 degrees points to the drive orientation system. The mention of stowing the boom and jib describes the safe travel position that reduces unexpected movements. The technician’s hint about a button and a signal describes the small drive orientation switch and its beeps.
Conclusions
A calm lesson from a stubborn machine
The episode with the EC600SJP shows that a boom lift that “does nothing” is often doing exactly what it should. The machine in this story was not broken. Its safety systems were protecting the operator from two different risks: a foot pressed for too long on the footswitch without a clear command, and a boom rotated so far around that “forward” and “backward” were no longer obvious.
Once the footswitch logic and the drive orientation system are understood, the behaviour becomes less mysterious. A simple sequence emerges. The foot comes off the pedal and back on again when the FSW interlock trips. The turret is stowed or, when work demands that it stay swung over the rear, the operator uses the small orientation button and the joystick to confirm the true direction of travel.
For new operators, or for those reading a mix of languages and symbols on a crowded control panel, patient explanations and small definitions like “jib” and “stow position” matter as much as any spare part. The story of this single machine on a wet day in 2025 becomes a gentle reminder: when a modern boom lift refuses to move, it may not be saying “I cannot.” It may simply be saying, “Please, confirm that this is safe.”
Selected References
Further reading
[1] JLG Industries. “EC600SJP Electric Boom Lift.” Product page for the EC600SJP, including basic specifications and a note that the model offers electric telescopic reach with a rotating jib. https://www.jlg.com/en/equipment/boom-lifts/telescopic/electric-hybrid/ec600-and-h600-series/ec600sjp
[2] JLG Industries. “JLG 1250AJP Service Manual.” Manual excerpt on Manualslib listing flash code “FSW INTERLOCK TRIPPED” as the condition where the footswitch remains closed for seven seconds with no function selected. https://www.manualslib.com/manual/987451/Jlg-1250ajp.html?page=86
[3] JLG Industries. “Service and Maintenance Manual: Model 600S / 660SJ.” Official JLG manual describing FSW-related fault codes and clarifying that the controller expects the footswitch to be released and pressed again after an interlock event. https://csapps.jlg.com/OnlineManuals/Manuals/JLG/JLG%20Boom%20Lifts/600S_600SJ_660SJ/Service%20manuals/SN%200300171769%20to%200300235167/Service_3121298_04-10-18_Global_English.pdf
[4] JLG Industries. “How to Operate the JLG Boom Lift Drive Orientation System.” DirectAccess article describing how the drive orientation system activates when the boom is swung past the rear drive wheels, disabling drive and steer until the operator uses the orientation switch. https://www.jlg.com/en/directaccess/how-to-operate-the-jlg-boom-lift-drive-orientation-system
[5] JLG Industries. “How to Activate the Aerial Work Platform Drive Orientation System.” DirectAccess explainer on the role of the orientation switch on newer aerial work platforms and the conditions that trigger drive orientation protection. https://www.jlg.com/en/directaccess/how-to-activate-the-awp-drive-orientation-system
[6] JLG Industries. “How to Operate the JLG Boom Lift Drive Orientation System.” Official JLG Industries video on YouTube showing the drive orientation indicator, the orientation switch, and the confirmation sequence for restoring drive and steer. https://www.youtube.com/watch?v=9Ob2Sp_vXL0
Appendix
Boom lift
A self-propelled machine with a powered boom and a small work platform at its tip, used to lift people and tools to height for construction, maintenance, and inspection work.
Drive orientation system
A safety feature that disables drive and steer when the boom is swung past the rear wheels and requires the operator to press an orientation button and move the joystick in the correct direction to confirm awareness of how the machine will move.
EC600SJP
An electric telescopic boom lift model from JLG Industries with long horizontal and vertical reach, a rotating jib at the boom tip, and a drive orientation system designed for safe operation on urban and industrial sites.
Footswitch
A pedal on the platform floor that must be pressed to enable boom and drive functions; it acts as a dead-man control so that movement stops if the operator steps away or loses balance.
Jib
The short outer boom section attached to the end of the main boom, carrying the work platform and able to move independently up and down for fine positioning.
Stow position
The compact travel configuration in which the main boom is lowered and retracted, the jib is folded into a safe angle, and the upper structure is aligned with the chassis so the machine is ready to move or be transported.
Tilt sensor
An electronic device that measures how far the machine or platform is leaning; when the angle exceeds a safe limit it can trigger warnings or block certain functions to reduce the risk of overturning.
Turret
The rotating upper part of a boom lift that carries the boom, jib, platform, and platform controls and can swing around on top of the chassis to position the platform where work is needed.
My Diary - Leonardo Cardillo 