JLG Telehandler 33261 Fault Code: UGM Output Drivers - Transmission D Coil - Open Circuit
UGM Output Drivers - Transmission D Coil - Open Circuit · ai-assisted, editor-reviewed · Last updated 2026-07-13
TL;DR
Code 33261 sets when the UGM (universal ground module or similar control module) detects an open circuit at output J1-20, the transmission D control coil, on machines configured for a powershift transmission. The machine flashes the gear selection symbol on the cabin display, disables 1st gear selection, and limits the operator to 2nd, 3rd, and 4th gears until the fault is cleared and power is cycled.
Medium severity. The machine keeps running and stays drivable in 2nd, 3rd, and 4th gear, so this is not an immediate shutdown situation. But losing a gear selection, especially 1st gear which is often needed for precise low-speed maneuvering and heavy loads, is a real operational limitation that should be diagnosed the same shift it appears.
What does JLG Telehandler error code 33261 mean?
Fault code 33261 points to an open circuit on the output that controls the transmission D coil, wired through connector position J1-20 on the UGM. This coil is one of the solenoids the control module energizes to shift the powershift transmission into a specific gear. When the module cannot detect the expected electrical load on that output, it assumes the wire or coil has failed open.
Because the control module cannot verify the D coil circuit is intact, it deactivates that output as a protective measure. That gear will not be available for selection at all. The machine's display flashes the gear selection symbol on the LCD to alert the operator that gear range is restricted.
This code is specific to machines configured with a powershift transmission. If the transmission configuration is different, this particular trigger condition would not apply the same way.
What triggers a JLG Telehandler 33261 code?
The UGM sets this fault when the transmission configuration is set to powershift and the module detects an open circuit at output J1-20, the transmission D control coil driver. No voltage, resistance, or time threshold is given for how the open circuit is detected.
Common causes of 33261
- Open circuit in the wiring harness between the UGM output J1-20 and the transmission D control coil, often from a broken wire, chafed insulation, or a pulled connector pin
- Failed or burned-out transmission D control coil itself, meaning the solenoid winding is open internally
- Corroded, loose, or unseated connector terminals at J1-20 or at the coil connector, breaking the circuit path without a full wire break
- Damaged or unseated pin in the UGM connector housing that prevents a complete circuit even though the harness itself is intact
How to troubleshoot JLG Telehandler 33261: first checks
- Check the cabin display for the flashing gear selection symbol to confirm the fault is active before starting teardown
- With the machine safely shut down and keys out, inspect the wiring harness from the UGM connector at J1-20 back to the transmission D control coil for visible damage, chafe points, or pinched sections
- Inspect the UGM connector and the transmission coil connector for corrosion, moisture intrusion, bent or backed-out pins, and loose terminals
- Test continuity across the D coil winding and across the harness run from J1-20 to the coil to isolate whether the open circuit is in the coil, the harness, or a connector
- Confirm the transmission configuration setting is correctly set to powershift, since this fault only applies under that configuration
How the code clears
This fault latches until the machine's power is cycled. After repairing the open circuit, whether that means replacing a damaged wire, reseating or replacing a connector, or replacing the transmission D control coil, turn the machine off and back on to allow the UGM to re-evaluate the circuit and clear the latch. No separate reset procedure is listed for this code beyond the power cycle.
Frequently asked questions
What does fault code 33261 mean on a JLG telehandler?
It means the control module found an open circuit at the transmission D control coil output, wired at J1-20, on a machine configured for a powershift transmission. The module disables that gear selection and the operator is left with 2nd, 3rd, and 4th gear only.
Can I keep working with fault code 33261 active?
The machine stays drivable in 2nd, 3rd, and 4th gear, so limited operation is possible. However, losing access to one gear range can affect low-speed control and load handling, so it's best to diagnose and repair the open circuit before continuing extended operation.
Why does the display keep flashing the gear selection symbol?
The flashing gear selection symbol on the LCD is the module's way of telling the operator that a gear range has been disabled due to this fault. It will keep flashing as long as the fault is active.
How do I clear code 33261 after fixing the wiring?
Once the open circuit is repaired, whether in the wiring, connector, or coil, cycle the machine's power off and back on. This fault latches until a power cycle, and no separate reset procedure is listed.
What usually causes an open circuit at the transmission D coil?
Common causes include a broken or chafed wire between the UGM output and the coil, a failed coil winding, corroded or loose connector terminals, or a damaged pin in the UGM connector housing.
Does this code apply to all JLG telehandler transmissions?
No. This fault is tied specifically to machines with a powershift transmission configuration. The UGM only monitors and triggers this open circuit fault under that configuration.
Is fault code 33261 dangerous to ignore?
It is not an immediate safety shutdown, but running with a restricted gear range and an unresolved open circuit can lead to further electrical or drivetrain issues if left unaddressed. Treat it as a same-shift diagnostic priority.