JLG Telehandler 33199 Fault Code: UGM Output Drivers - Auxiliary Function-B Valve - Open Circuit
UGM Output Drivers - Auxiliary Function-B Valve - Open Circuit · ai-assisted, editor-reviewed · Last updated 2026-07-13
TL;DR
Fault code 33199 sets when the JLG Universal Ground Module (UGM) detects an open circuit or lost current feedback on the auxiliary function-B valve output at connector J2-20. The machine responds by shutting off that valve output, disabling continuous auxiliary hydraulics, and turning off the continuous auxiliary hydraulics indicator. The fault latches until the machine is power cycled.
Medium severity. This code does not stop the machine from driving or lifting, but it disables the auxiliary function-B valve and the continuous auxiliary hydraulics feature. Any attachment or tool relying on that valve or on continuous auxiliary flow will not work until the fault is cleared and the circuit repaired.
What does JLG Telehandler error code 33199 mean?
Fault code 33199 is an output driver fault from the JLG UGM, the module that controls various machine outputs including hydraulic valve solenoids. This specific code points to the auxiliary function-B valve circuit at output J2-20.
The UGM continuously monitors the current flowing through this output. If it sees an open circuit, meaning no continuous electrical path, or if it loses the current feedback signal it expects, it sets an internal flag and raises this fault.
Because the system cannot confirm the valve is working correctly, the UGM shuts down that valve output as a protective step, and it also disables and inhibits the continuous auxiliary hydraulics feature and turns off its indicator light. This prevents the machine from running an auxiliary function it cannot verify is under control.
What triggers a JLG Telehandler 33199 code?
The UGM detects an open circuit at output J2-20 (auxiliary function-B valve) or detects a current feedback lost condition on that output. Internally, the UGM sets a flag to determine whether this open circuit or feedback loss condition is the actual cause of the fault before latching the code.
Common causes of 33199
- An open circuit in the wiring between the UGM and the auxiliary function-B valve solenoid at output J2-20
- A disconnected, corroded, or damaged connector pin at the J2-20 circuit
- A failed or open solenoid coil on the auxiliary function-B valve
- Loss of the current feedback signal the UGM uses to confirm the output is operating correctly, even if the circuit is not fully open
- A wiring harness fault such as a chafe, break, or pinch point along the auxiliary function-B valve circuit
How to troubleshoot JLG Telehandler 33199: first checks
- Inspect the wiring harness and connectors at the auxiliary function-B valve and back to the UGM output J2-20 for looseness, corrosion, or damage
- Check the solenoid coil on the auxiliary function-B valve for continuity and confirm it is not open or burned out
- Verify the connector at J2-20 is fully seated and pins are not bent, pushed back, or corroded
- Trace the harness run for chafe points, pinches, or rodent damage between the UGM and the valve
- Confirm the continuous auxiliary hydraulics indicator and feature are disabled as expected, which confirms the UGM has responded to the fault correctly
How the code clears
This fault latches until the machine is power cycled. After repairing the open circuit or restoring the current feedback path, cycle machine power off and on to clear the fault and re-enable the auxiliary function-B valve output and continuous auxiliary hydraulics feature. No separate reset procedure is listed for this code beyond the power cycle.
Frequently asked questions
What does fault code 33199 mean on a JLG telehandler?
It means the UGM detected an open circuit or a lost current feedback signal on the auxiliary function-B valve output at J2-20. The UGM disables that valve and the continuous auxiliary hydraulics feature until the machine is power cycled after the fault is fixed.
Will code 33199 stop my telehandler from driving or lifting?
No. This fault only affects the auxiliary function-B valve output and the continuous auxiliary hydraulics feature. Driving, steering, and lifting functions are not directly disabled by this code.
Why did my continuous auxiliary hydraulics indicator turn off?
The UGM automatically turns off the continuous auxiliary hydraulics indicator and disables the feature as part of its response to detecting the open circuit or feedback loss on the auxiliary function-B valve output.
How do I clear fault code 33199 after repairing the wiring?
Cycle the machine's power off and on. This code latches until a power cycle, and no separate reset procedure is listed beyond that.
What should I check first if I get a 33199 fault?
Start with the wiring and connector at output J2-20 and the auxiliary function-B valve solenoid. Look for loose or corroded connections, chafed harness sections, and test the solenoid coil for continuity.
Can a bad connector cause code 33199 even if the wiring is intact?
Yes. A connector that is not fully seated or has corroded or bent pins can create an open circuit or interrupt the current feedback the UGM relies on, triggering this fault even if the wire itself is undamaged.