JLG Scissor Lift 2347 Fault Code: Ground Controls - System Interlock - Set Joystick Inputs to Neutral
Ground Controls - System Interlock - Set Joystick Inputs to Neutral · ai-assisted, editor-reviewed · Last updated 2026-07-13
TL;DR
Code 2347 is a Ground Controls System Interlock fault on JLG scissor lifts. It sets when the UGM (upper ground module or similar control unit) detects a joystick input that is not centered or neutral at a moment when it must be, usually tied to the hydraulic quick connect switch, the S4 button, or the auxiliary hydraulics release feature. The machine reports machine system distress and shuts down joystick functionality until the joysticks are returned to neutral.
Medium severity. The lift does not report a mechanical or electrical failure risk here. It is an interlock catching an out-of-sequence operator input or switch state. Function is deactivated until corrected, so it stops work but does not indicate impending component damage.
What does JLG Scissor Lift error code 2347 mean?
Fault 2347 is a system interlock check built into the ground control logic. Its job is to make sure the joystick rollers and X-axis/Y-axis inputs are centered, or neutral, at specific points in the sequence of using auxiliary hydraulics and the hydraulic quick connect feature. If the controller sees the joystick out of neutral when it expects neutral, it flags machine system distress and locks out joystick control as a precaution.
This is not a wiring or sensor failure code by itself. It is the controller enforcing a safe operating sequence: hydraulics quick connect, S4 button presses, the 'S' switch, and bucket mode with platform attached all have to happen with the joystick centered, or the system assumes the operator input is unintended or unsafe and stops it.
Because it disables joystick functionality until the fault clears, it directly affects the operator's ability to move the platform or run auxiliary hydraulics, so it needs to be resolved before continuing work.
What triggers a JLG Scissor Lift 2347 code?
The UGM sets this fault under any of several conditions: the hydraulic quick connect switch is activated while another auxiliary hydraulics function is already active; the joystick roller(s) and/or X-axis and/or Y-axis are not neutral when the hydraulic quick connect switch is released; the hydraulic quick connect switch is activated but the S4 button is not the next operator action detected; the joystick is not neutral when the 'S' switch activates the auxiliary hydraulics release feature; the auxiliary hydraulics release feature is active and the platform is then detected as attached; the hydraulic quick connect switch is activated and S4 is activated but then released; the quick connect feature is active and S4 is released; the platform is detected as attached with bucket mode active while the joystick is not neutral or an S1 through S4 button or the trigger switch is engaged with the joystick lock feature enabled; or the S4 button is engaged while the joystick roller and/or X-axis and/or Y-axis are not neutral. The auxiliary hydraulics release feature will suppress this fault when it is active.
Common causes of 2347
- Operator moved the joystick, or left a roller/axis input off-center, during a hydraulic quick connect or auxiliary hydraulics sequence that requires neutral.
- S4 button pressed, activated, or released out of the expected sequence relative to the hydraulic quick connect switch.
- The 'S' switch triggered the auxiliary hydraulics release feature while the joystick was not centered.
- Platform detected as attached while bucket mode is active and the joystick, S1 through S4 buttons, or trigger switch are engaged with the joystick lock feature enabled.
- A joystick roller, X-axis, or Y-axis potentiometer or contact not returning cleanly to center, which can mimic an out-of-sequence input even when the operator believes the stick is neutral.
How to troubleshoot JLG Scissor Lift 2347: first checks
- Release all joystick inputs, rollers, X-axis, Y-axis, and buttons, and return the joystick fully to its centered, neutral position, then see if the fault clears.
- Review the operator's sequence: confirm the hydraulic quick connect switch, S4 button, and 'S' switch are being used in the order the machine expects, without pressing or releasing them while the joystick is off-center.
- Inspect the joystick for physical binding, damage, or a roller/axis that does not spring back cleanly to center; a mechanically sticky joystick can trigger this fault even during normal use.
- If bucket mode and platform-attached status are involved, verify the platform attachment sensing and bucket mode switch are functioning and reporting correctly.
- Check that the joystick lock feature status matches what the operator expects; if it is enabled, S1 through S4 or the trigger switch being engaged with the joystick off-center will set this fault.
How the code clears
The fault is latched until joystick inputs are in the neutral position. No separate clearing step is listed beyond returning all joystick rollers and the X-axis and Y-axis to center. Once neutral is confirmed, joystick functionality should be restored automatically.
Frequently asked questions
What does JLG fault code 2347 mean?
It means the ground control system detected a Ground Controls System Interlock condition, where a joystick input was not neutral or centered at a point in the operating sequence where it needed to be, usually involving the hydraulic quick connect switch, S4 button, or auxiliary hydraulics release feature. The machine responds by disabling joystick functionality.
Is fault 2347 dangerous to keep operating with?
The lift itself deactivates and inhibits joystick functionality when this fault is active, so you cannot continue operating the affected functions until it clears. It is an interlock protecting against unintended movement, not a sign of hydraulic or electrical failure by itself.
How do I clear fault code 2347 on a JLG scissor lift?
Return all joystick rollers and the X-axis and Y-axis to the neutral, centered position. The fault is latched until neutral is confirmed, and no additional reset procedure is listed.
Why does this fault keep coming back?
Repeated faults usually point to a joystick that is not returning cleanly to center, an operator sequence that presses S4 or the quick connect switch while the joystick is still active, or the joystick lock feature being enabled while S1 through S4 or the trigger switch are engaged with the platform attached in bucket mode.
Does the auxiliary hydraulics release feature affect this fault?
Yes. If the auxiliary hydraulics release feature is active, it will suppress fault 2347. It can also be a trigger itself if the joystick is not neutral when the 'S' switch causes that feature to engage.
What is the UGM referenced in this fault?
The UGM is the control module responsible for monitoring ground control inputs and enforcing this interlock. It is the component that detects the out-of-neutral joystick conditions and sets the fault.