Bobcat H1224 (12-24) Fault Code: Front Auxiliary Thumb Paddle Switch Not in Neutral
Also shown on the panel as 12-24 · Also called Auxiliary PWM Switch Not in Neutral, Front Auxiliary Thumb Paddle Switch Not In Neutral, Right Thumb Switch Not in Neutral
Front Auxiliary Thumb Paddle Switch Not in Neutral · ai-assisted, editor-reviewed · Last updated 2026-07-13
TL;DR
Bobcat code H1224 (panel form 12-24) sets when the auxiliary controller sees the front auxiliary thumb paddle switch out of neutral while auxiliaries are enabled. Front auxiliary outputs shut off until the switch reads neutral and the fault clears. Most cases trace to the operator's hand position, a wiring short, or a bad connector, but a failing right handle or auxiliary controller can also cause it.
Medium severity. The machine keeps running but front auxiliary hydraulic functions are locked out, which stops attachment work until the switch is verified in neutral and the fault is fixed. It is not an engine or structural safety event, but it can halt productivity on the job.
What does Bobcat error code H1224 mean?
H1224 is set by the auxiliary controller when it sees the front auxiliary thumb paddle switch reporting a position other than neutral at the moment auxiliaries are enabled. Because the controller cannot confirm the switch is safely centered, it disables the front auxiliary outputs as a precaution so an attachment cannot be commanded unexpectedly.
On manual and ACS controlled machines, the thumb paddle switch sends a variable voltage back to the auxiliary controller on signal wire 4320, with neutral normally reading 3.5 - 4.5 volts. The controller supplies the switch 8.0 volts on wire 4300. On AWS/SJC loaders, the same right thumb paddle information travels over CAN communication wires instead of a simple analog signal.
If you are running the machine with remote control and see H1224, Bobcat's diagnostic software includes a radio remote control diagnostics screen that can confirm the front auxiliary thumb paddle switch is working correctly.
Common causes of H1224
- Operator holding the front auxiliary thumb paddle switch out of neutral at the moment auxiliaries are enabled.
- 8-volt supply wire 4300 shorted to battery voltage.
- Signal wire 4320 shorted to supply voltage.
- Right handle fault (manual/ACS controlled machines only).
- Right CAN joystick grip fault (AWS/SJC controlled machines only).
- Auxiliary controller fault.
- Moisture, corrosion, or pushed back pins in the auxiliary controller connectors, right handle connector, right CAN joystick grip connector, or mainframe harness.
- Intermittent condition not present at time of testing: possible loose connections, corrosion, pushed back pins, the controller, or the wire harness, alone or in combination.
How to troubleshoot Bobcat H1224: first checks
- Confirm the operator is not holding or resting a hand on the thumb paddle switch when enabling auxiliaries, and cycle the switch to neutral before re-enabling.
- With key switch / (run/enter) on and auxiliaries enabled, check signal wire 4320 for voltage in the neutral range of 3.5 - 4.5 volts on manual and ACS controlled machines.
- Check the 8-volt supply wire 4300 for a short to battery voltage, and check signal wire 4320 for a short to supply voltage.
- Inspect the auxiliary controller connectors, right handle connector, right CAN joystick grip connector, and mainframe harness connectors for moisture, corrosion, or pushed back pins.
- On AWS/SJC loaders, check the CAN wiring (91xx/95xx and 92xx/96xx) for damage or poor connections instead of testing analog voltage.
- If running with remote control, use the radio remote control diagnostics screen in the diagnostic software to verify the front auxiliary thumb paddle switch operation.
- If the code is intermittent and not present during testing, recheck all connectors for loose or corroded terminals since the fault may not reproduce on demand.
How the code clears
The listed condition for clearing H1224 is simply that auxiliaries are enabled with the front auxiliary thumb paddle switch reading neutral. Once the switch shows a proper neutral signal and any wiring, connector, or component fault is repaired, enabling auxiliaries again should clear the code. No separate reset procedure is listed for this code.
Affected models and serial ranges
H1224 appears in our records across 18 Bobcat models. Match your machine by model and serial number.
| Model | Serial ranges |
|---|---|
| E35 | SN A93K110001-99999, SN AC2P11001-99999 |
| E45 | SN AHHC11001-99999 |
| S510 | SN A3NJ11001-99999, SN A3NK11001-99999, SN ATZC11001-99999 |
| S530 | SN A7TV11001-99999, SN ATZD11001-99999 |
| S550 | SN A3NK11001-A3NL99999, SN A3NM11001-99999 |
| S570 | SN A7U711001-799999, SN A7U811001-899999 |
| S590 | SN ANMN11001-99999, SN ANMP11001-99999 |
| S630 | SN A3NT12370-99999, SN A3NU11001-11111, SN A3NU11112-99999 |
| S650 | SN A3NV11001-13098, SN A3NV13099-99999, SN A3NW11001-11248, SN A3NW11249-99999 |
| S750 | SN A3P211001-299999 |
| S770 | SN A39511001-99999, SN A3P411001-99999 |
| T550 | SN A7UJ11001-AJZV12276 |
| T590 | SN ALJU11001-999999, SN B37811001-999999, SN B3Z711001-999999 |
| T630 | SN A7PU11001-11663, SN A7PU11664-99999 |
| T650 | SN A3P012214-099999, SN A3P111242-199999 |
| T750 | SN ANKA11001-A99999 |
| T770 | SN A3P811001-899999, SN A3P911001-999999 |
| T870 | SN A3PG11001-99999, SN A3PH11001-99999 |
Frequently asked questions
What does Bobcat code H1224 mean?
It means the auxiliary controller detected the front auxiliary thumb paddle switch was not in neutral when auxiliaries were enabled, so it disabled the front auxiliary outputs until the condition clears.
What is the panel display number for H1224?
The numeric panel form of H1224 is 12-24.
Why did my front auxiliary hydraulics stop working?
When H1224 sets, the auxiliary controller disables the front auxiliary outputs as a safety measure, so attachments run off the front auxiliary circuit will not respond until the switch reads neutral and the code clears.
Is H1224 a wiring problem or a switch problem?
It can be either. Bobcat lists causes ranging from the operator simply holding the paddle out of neutral, to shorted supply or signal wiring (4300 or 4320), to a bad right handle, right CAN joystick grip, or auxiliary controller, plus corrosion or pushed back pins in the related connectors.
Does H1224 apply the same way to CAN-equipped loaders?
Mostly, but the wiring differs. Manual and ACS controlled machines use analog voltage on wires 4320 and 4300, while AWS/SJC loaders send the right thumb paddle switch information over CAN communication wires (91xx/95xx and 92xx/96xx) instead.
I'm running a remote control unit and got H1224, what should I check?
Use the radio remote control diagnostics screen in the Bobcat diagnostic software to verify the front auxiliary thumb paddle switch is operating correctly before assuming a wiring or component fault.
The code only shows up sometimes, why can't the tech find it?
Bobcat notes that if H1224 is intermittent and not active during testing, the cause may not be found right away. Likely culprits in that case are loose connections, corrosion, pushed back pins, the controller, or the wire harness, or some combination of these.