JLG Telehandler 33246 Fault Code: UGM Output Drivers - Transmission Reverse Coil - Open Circuit
UGM Output Drivers - Transmission Reverse Coil - Open Circuit · ai-assisted, editor-reviewed · Last updated 2026-07-13
TL;DR
Fault 33246 sets when the UGM (Universal Ground Module, machine controller) detects an open circuit at output J2-32, the transmission reverse coil, on a machine configured for hydrostatic transmission. The controller deactivates that output and flashes the gear selection and drive direction symbols on the cabin display. It latches until the machine is power cycled.
High severity. This fault directly disables the reverse coil output on a hydrostatic transmission, which can leave the machine unable to shift into or hold reverse. It is not an engine-damage emergency, but it is a drivability and safety issue that should be diagnosed before continued operation, especially in areas requiring controlled backing maneuvers.
What does JLG Telehandler error code 33246 mean?
Fault 33246 is reported by the UGM, the machine's main controller, when it commands the transmission reverse coil at output J2-32 and detects an open circuit instead of a complete electrical path. This only applies to machines set up with a hydrostatic transmission configuration.
When this happens, the controller shuts off that output entirely to protect the circuit and avoid unpredictable transmission behavior. It also flashes the gear selection and drive direction symbols on the cabin's LCD display so the operator knows something is wrong with direction control.
Because the reverse coil output is disabled, the operator may lose the ability to select or hold reverse, or the transmission may behave inconsistently in that direction until the fault is cleared and the circuit is repaired.
What triggers a JLG Telehandler 33246 code?
A transmission configuration of hydrostatic is configured and the UGM detects an open circuit at this output.
Common causes of 33246
- A broken, corroded, or disconnected wire in the transmission reverse coil circuit between the UGM output J2-32 and the coil itself.
- A failed or open winding inside the transmission reverse coil solenoid itself.
- A loose, damaged, or corroded connector or pin at the coil connector or at the UGM harness connector.
- A pinched, chafed, or cut wire in the harness routing near the transmission, causing an open rather than a short.
How to troubleshoot JLG Telehandler 33246: first checks
- With the machine safely shut down and battery power isolated where appropriate, visually inspect the wiring harness between the UGM and the transmission reverse coil for damage, chafing, or disconnection.
- Check the connector at the transmission reverse coil and the corresponding UGM harness connector (J2-32) for corrosion, bent pins, or loose terminals.
- Test continuity through the reverse coil winding and through the harness wire itself to confirm where the open circuit exists.
- Confirm the transmission configuration setting is correctly set to hydrostatic, since this fault only applies under that configuration.
- Inspect for any recent repair, harness disturbance, or pest damage near the transmission area that could have introduced a break in the circuit.
How the code clears
This fault latches until the machine is power cycled. No separate clearing step is listed beyond cycling power after the open circuit has been physically repaired. Simply cycling power without fixing the underlying open circuit will likely cause the fault to reset again once the UGM re-checks the output.
Frequently asked questions
What does JLG fault code 33246 mean?
It means the UGM, the machine's controller, detected an open circuit at output J2-32, which drives the transmission reverse coil, on a machine configured for hydrostatic transmission. The controller disables that output and flashes the gear selection and drive direction symbols on the display.
Can I still drive the machine with fault 33246 active?
The reverse coil output is deactivated when this fault is active, so reverse function through that coil may not work correctly. It is best to treat this as a drivability issue and get it diagnosed before relying on the machine for normal operation.
How do I clear fault code 33246?
The fault latches until the machine is power cycled. No separate clearing procedure is listed, but power cycling alone will not fix the fault unless the open circuit causing it has actually been repaired.
What usually causes an open circuit in the transmission reverse coil circuit?
Common causes include broken or corroded wiring between the controller and the coil, a failed coil winding, a bad connector or pin, or a chafed or cut wire in the harness near the transmission.
Does this fault only apply to certain transmission types?
Yes. This fault only triggers when the transmission is configured as hydrostatic. If the machine uses a different transmission configuration, this specific fault logic does not apply.
Why does the display flash the gear selection and drive direction symbols?
The UGM flashes those symbols on the cabin LCD as a direct signal to the operator that there is a problem with drive direction control, tying the visual warning to the disabled reverse coil output.