Bobcat H3913 (39-13) Fault Code: Left CAN Joystick Grip No Communication
Also shown on the panel as 39-13 · Also called Left Joystick Grip No Communication
Left CAN Joystick Grip No Communication · ai-assisted, editor-reviewed · Last updated 2026-07-13
TL;DR
Bobcat code H3913 (panel form 39-13) means the auxiliary controller cannot communicate with the left joystick grip. It can also set if the left thumb paddle switch is out of neutral when the key switch is turned to run/enter. When active, the machine disables the auxiliaries. The code is self resetting once the fault condition clears.
Medium severity. H3913 disables auxiliary functions but does not by itself stop the machine from driving or lifting. Treat it as a stop-and-diagnose issue before relying on auxiliary-controlled attachments, since loss of aux control mid-task can be a safety problem depending on the attachment in use.
What does Bobcat error code H3913 mean?
Code H3913 (shown as 39-13 on the panel) is set by the auxiliary controller when it loses communication with the left joystick grip. The left joystick grip and left joystick base talk to each other and to the controller, and if that link breaks, the system cannot trust the joystick's inputs for auxiliary control.
One specific trigger noted for this code is the left thumb paddle switch being out of neutral at the moment the key switch is turned to run/enter. If the controller sees that switch already active instead of neutral at power-up, it will not know if the input is valid, so it sets the code as a safety measure.
When H3913 is active, the auxiliaries are disabled. This is intentional: the controller will not run auxiliary functions off a joystick it cannot properly read or communicate with.
Common causes of H3913
- Left joystick thumb paddle switch out of neutral when the key switch/(run/enter) is turned on
- Fault in the left joystick grip itself
- Fault in the left joystick base
- Wire harness fault between the left joystick grip and the left joystick base
- Possible wire pinch on the air ride seat power connector (listed on machines equipped with this feature)
- Moisture, corrosion, or pushed-back pins in the left joystick assembly
- Loose connections, corrosion, pushed-back pins, the controller, the wire harness, or a combination of these, particularly on intermittent faults not present at the time of testing
How to troubleshoot Bobcat H3913: first checks
- Cycle the key switch off and back to run/enter with the left thumb paddle switch confirmed in neutral, and see if the code clears since an out-of-neutral condition at power-up is a listed cause
- Inspect the left joystick grip and base connectors for moisture, corrosion, or pushed-back pins
- Trace and inspect the wire harness running between the left joystick grip and the left joystick base for damage, chafing, or loose connections
- Check the air ride seat power connector area for a pinched wire, since this is specifically called out as a possible cause on machines with that connector routing near the joystick circuit
- If the code is intermittent and not present during testing, recheck all connections in the circuit including the controller and harness, since the root cause may not show up on a single test
How the code clears
H3913 is self resetting. No separate clearing step or procedure is listed beyond correcting the cause. Once the communication fault or out-of-neutral condition is resolved, the code should clear on its own.
Affected models and serial ranges
H3913 appears in our records across 16 Bobcat models. Match your machine by model and serial number.
| Model | Serial ranges |
|---|---|
| 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 H3913 mean?
It means the auxiliary controller has lost communication with the left joystick grip, or detected the left thumb paddle switch out of neutral when the key switch was turned to run/enter. The controller responds by disabling the auxiliaries.
Will H3913 stop my Bobcat from driving?
The code specifically disables the auxiliaries, tied to the left joystick grip communication. It is not described as disabling drive function, but you should not continue relying on auxiliary-controlled attachments until the fault is diagnosed.
Why does my machine throw H3913 every time I start it?
This often points to the thumb paddle switch not being in neutral when the key switch is turned on. Make sure the paddle switch is fully released to neutral before starting, then check for a repeat of the code.
Do I need to reset H3913 manually?
No. The code is self resetting once the underlying condition is corrected. No separate clearing procedure is listed.
What is the air ride seat power connector got to do with my joystick code?
On machines with an air ride seat, a wire in that seat's power connector circuit can get pinched, and this has been identified as a possible cause tied to the left joystick grip communication fault.
The code comes and goes, what should I check?
Intermittent H3913 codes are harder to pin down. Check for loose connections, corrosion, and pushed-back pins in the left joystick grip, base, and harness, and don't rule out the controller itself if the wiring checks out clean.
Which Bobcat models can show code H3913?
It applies to the S510, S530, S550, S570, S590, S630, S650, S750, S770, T550, T590, T630, T650, T750, T770, and T870 models.