DiagnosticsHigh severity

Bobcat H3916 (39-16) Fault Code: Left CAN Joystick Base No Communication

Also shown on the panel as 39-16 · Also called Left Joystick No Communication

Left CAN Joystick Base No Communication · ai-assisted, editor-reviewed · Last updated 2026-07-13

TL;DR

H3916 (panel form 39-16) sets when the auxiliary controller stops receiving CAN messages from the left joystick base, or when two right joystick bases are connected by mistake. Drive functions are disabled while the code is active, and if the loader is in H-pattern mode, lift and tilt are disabled too.

High severity. H3916 shuts down drive, and in H-pattern mode also disables lift and tilt, so the machine loses key functions until the fault is fixed. It is not an engine-damage emergency, but it stops productive work and can leave an operator without full control in the cab.

What does Bobcat error code H3916 mean?

H3916 is a communication fault on the CAN network that links the left joystick base to the auxiliary controller. The joystick base is the electronic module inside the left control pod that reads grip movements and sends them out as CAN messages to the machine's controllers.

When the auxiliary controller stops seeing those messages, it cannot trust or process left joystick input, so it disables the drive functions as a safety measure. If the loader is set up in H-pattern (where joystick movement also controls lift and tilt), those functions are disabled as well since they run through the same communication path.

This same code can also be triggered if two right joystick bases are wired into the system instead of one left and one right, since the controller will not receive the expected left-side messages at all in that case.

Common causes of H3916

Code H4048 'Right Joystick Multiple' present at the same time
Supply wire 1840 or ground wire 2080 open
CAN communication wires open between the left joystick base and the controller
Fault inside the left joystick grip
Fault inside the left joystick base itself
Damaged or open wires between the left joystick base and the left joystick grip
Two right joystick bases connected instead of a left and a right
Moisture, corrosion, or pushed-back pins in the mainframe harness, SJC harness, or left joystick harness
Intermittent fault not present at time of testing, possibly from loose connections, corrosion, pushed-back pins, the controller, the wire harness, or a combination of these

How to troubleshoot Bobcat H3916: first checks

Turn the key switch to run/enter (the code sets under this condition) and confirm the code is active or check if it was only intermittent
Check for Code H4048 'Right Joystick Multiple' at the same time, which points toward two right joystick bases being connected instead of a left and a right
Inspect the mainframe harness, SJC harness, and left joystick harness connectors for moisture, corrosion, or pins that have pushed back out of their sockets
Check supply wire 1840 and ground wire 2080 for continuity and open circuits
Check the CAN communication wires between the left joystick base and the controller for opens or damage
Wiggle-test the wiring between the left joystick base and the left joystick grip while watching for the code to trigger
If nothing is found and the fault will not repeat, treat it as intermittent and recheck all connectors, the harness, and the controller together rather than assuming a single part is bad

How the code clears

The code is self resetting. No separate manual clearing step is listed once the wiring or component issue causing the loss of CAN communication has been repaired.

Affected models and serial ranges

H3916 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

Safety-critical: confirm before use

Electrical safety: stop the engine before inspecting wiring, fuses, connectors, or drive belts, and avoid shorting power terminals. Thresholds, component locations, wire numbers, fuse locations, and reset procedures can vary by model, configuration, and serial number. Confirm them in the service documentation for your exact machine.

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Frequently asked questions

What does Bobcat code H3916 mean?

It means the auxiliary controller is not receiving CAN communication messages from the left joystick base, or two right joystick bases have been connected in place of a left and a right. Drive functions get disabled, and lift and tilt are also disabled if the loader is running H-pattern control.

Can I keep operating the machine with H3916 active?

Drive functions are disabled while this code is active, and in H-pattern mode lift and tilt are disabled too, so normal operation is not possible until the fault clears. It should be diagnosed and repaired before returning the machine to work.

Does H3916 clear itself after I fix the wiring?

Yes. The code is self resetting once the underlying wiring or component problem causing the loss of communication is repaired. No separate manual reset procedure is listed.

Why would H3916 show up along with H4048?

H4048 is 'Right Joystick Multiple.' If it appears alongside H3916, it suggests two right joystick bases have been connected instead of one left and one right base, which the controller reads as a missing left joystick.

What wires should a technician check first for H3916?

Start with supply wire 1840 and ground wire 2080 for open circuits, then check the CAN communication wires between the left joystick base and the controller, along with the wiring between the left joystick base and the left joystick grip.

Why does H3916 sometimes disappear and come back later?

Intermittent CAN faults are often caused by loose connections, corrosion, or pins that have pushed back out of their sockets in the mainframe, SJC, or left joystick harness. If the code is not active during testing, these connectors and the controller itself should still be checked carefully.