Bobcat A8103 (81-03) Fault Code: ACD/RACD Output "B" Error Off
Also shown on the panel as 81-03 · Also called ACD Output ‘B’ Error Off
ACD/RACD Output "B" Error Off · ai-assisted, editor-reviewed · Last updated 2026-07-13
TL;DR
Bobcat fault code A8103 (panel display 81-03) sets when the ACD/RACD controller sends voltage to energize the attachment solenoid on output "B" (wire 5200) but detects no voltage return, or detects a large current draw and shuts the output off. The ACD/RACD icon on the right instrument panel will blink and the attachment on output "B" will stop working.
Medium severity. The affected attachment output will not function until the fault is corrected, which can stop attachment work but does not by itself threaten the machine's core drive or lift systems. Treat it as a stop-and-diagnose issue rather than an emergency shutdown.
What does Bobcat error code A8103 mean?
A8103 is a Bobcat Attachment Control Device (ACD) or Remote Attachment Control Device (RACD) fault. The ACD/RACD controller manages power to attachment solenoids so implements like grapples, augers, or other hydraulically actuated tools can be switched on and off from the cab.
This specific code applies to output "B," wired through wire 5200 to an attachment solenoid coil. When the controller commands that output on, it expects to see voltage present. If it sees no voltage after sending the command, or if it senses a large current draw and shuts the output off to protect itself, it logs A8103 and flashes the ACD/RACD icon on the right instrument panel.
In practical terms, the attachment function wired to output "B" will not operate until the underlying electrical problem is found and fixed.
Common causes of A8103
- Shorted solenoid coil on the attachment connected to output "B".
- Circuit output "B" wire 5200 to the attachment solenoid shorted to ground.
- A fault in the ACD/RACD controller itself.
- Moisture, corrosion, or pushed-back pins in the mainframe or attachment control harness connectors.
- Intermittent causes that may not be pinpointed if the fault is not active during testing, including loose connections, corrosion, pushed-back pins, the controller, the wire harness, or a combination of these problems.
How to troubleshoot Bobcat A8103: first checks
- Confirm the key switch is in the run/enter on position, since this is the condition required for the code to be present, then check the right instrument panel for the blinking ACD/RACD icon.
- Inspect the attachment solenoid coil connected to output "B" for signs of a shorted coil, using a resistance check against the coil's rating and looking for burnt or melted insulation.
- Trace wire 5200 from the ACD/RACD controller to the attachment solenoid and check for chafing, pinched sections, or contact with ground (bare metal or the machine frame).
- Open up the mainframe and attachment control harness connectors and look closely for moisture intrusion, corrosion on the pins, or pins that have been pushed back out of their sockets.
- If the fault is not currently active, wiggle-test the harness and connectors at the mainframe and attachment interface while watching for the fault to reappear, since intermittent faults may not show up during a static check.
- If wiring and the solenoid check out clean, suspect the ACD/RACD controller itself as the source of the fault.
How the code clears
Once the repair is complete, the code is cleared by cycling power to the machine. No separate clearing step is listed.
Affected models and serial ranges
A8103 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 |
Frequently asked questions
What does Bobcat code A8103 mean?
It means the ACD/RACD controller tried to energize the attachment solenoid on output "B" (wire 5200) but did not see the expected voltage return, or it shut the output off after sensing a large current draw. The attachment wired to that output will not work until the fault is fixed.
What is the panel display number for A8103?
On the instrument panel it displays as 81-03, alongside a blinking ACD/RACD icon on the right instrument panel.
Which Bobcat machines can show code A8103?
It applies across the S510, S530, S550, S570, S590, S630, S650, S750, S770, T550, T590, T630, T650, T750, and T770 skid steer and track loader lineup, as well as the T870.
Can I clear A8103 myself after a repair?
Yes. Once the underlying cause is fixed, cycling power to the machine is the listed step to clear the code. There is no separate reset procedure beyond that.
Why does the attachment on output "B" stop working with this code?
The ACD/RACD controller shuts off output "B" when it detects no voltage return after energizing the solenoid, or when it senses excessive current draw, to protect the circuit. That shutdown is what disables the attachment function tied to that output.
What if the code comes and goes intermittently?
Intermittent A8103 faults can be harder to pin down, since the root cause may not be present at the time of testing. Likely culprits include loose connections, corrosion, pushed-back pins, the wire harness, or the controller itself, sometimes in combination.
Is A8103 a safety-critical fault?
It is primarily an attachment electrical fault rather than a core drive or lift safety issue. Still, any short to ground or controller fault should be diagnosed before returning the attachment to work, since the underlying wiring problem could affect other circuits.