DiagnosticsMedium severity

Bobcat A8305 (83-05) Fault Code: ACD/RACD Output “D” Short to Battery

Also shown on the panel as 83-05 · Also called ACD Output ‘D’ Short to Battery

ACD/RACD Output “D” Short to Battery · ai-assisted, editor-reviewed · Last updated 2026-07-21

TL;DR

Bobcat fault code A8305 (panel display 83-05) means the ACD/RACD controller detected voltage on output "D" at controller pin J1 B-25 when that output was not commanded on. The controller disables output "D" as a protective response until the fault is fixed and power is cycled.

Medium severity. Output "D" is disabled once the code sets, which means whatever attachment function relies on that output will stop working. This is not an engine-damage emergency, but the affected attachment function is unusable until repaired, so it should be diagnosed before the machine goes back into production use with that attachment.

What does Bobcat error code A8305 mean?

A8305 is set by the ACD/RACD controller (Attachment Control Device / Rear Attachment Control Device) when it sees voltage present on output "D", at controller pin J1 B-25, at a time when the controller itself did not command that output active. In plain terms, the controller expects that circuit to be off and instead finds it energized from somewhere else.

This is a "short to battery" fault, meaning the output wire or its return path is picking up battery voltage from an unintended source rather than from the controller's own switching. Because the controller cannot trust or control that output anymore, it shuts output "D" down entirely until the issue is corrected and power is cycled.

This code applies to Bobcat E35, E42, E45, E55, S510, S530, S550, S570, S590, S630, S650, S750, S770, T550, T590, T630, T650, T750, and T770/T870 models equipped with ACD/RACD attachment control.

Common causes of A8305

Output "D" wire at controller pin J1 B-25 shorted to battery voltage.
Return wire at controller pin J1 A-27 shorted to battery voltage.
Faulty output "D" solenoid.
Faulty ACD/RACD controller.
Moisture, corrosion, or pushed-back pins in the ACD/RACD controller connectors, mainframe harness, attachment control harness, or the output "D" solenoid connector.
Intermittent fault: loose connections, corrosion, pushed-back pins, the controller, or the wire harness, alone or in combination, if the code is not currently active during testing.

How to troubleshoot Bobcat A8305: first checks

Confirm the code is present with key switch / (run/enter) on before starting diagnosis, since that is the condition under which the controller sets this code.
Inspect the output "D" circuit at controller pin J1 B-25 for a short to battery voltage, checking harness routing for chafe points against powered wiring.
Inspect the return wire at controller pin J1 A-27 for an unwanted connection to battery voltage.
Check the output "D" solenoid for an internal short or wiring fault feeding battery voltage back into the signal circuit.
Open and inspect the ACD/RACD controller connectors, mainframe harness connectors, attachment control harness connectors, and the output "D" solenoid connector for moisture, corrosion, or pushed-back pins.
If the code is not active at the time of testing, treat it as intermittent: recheck all connections for looseness, corrosion, or pushed-back pins, and inspect the harness and controller since any of these, alone or combined, can cause an intermittent short to battery.
If wiring, connectors, and the solenoid all check good, suspect the ACD/RACD controller itself.

How the code clears

Once the short to battery has been found and repaired, cycle power (turn the key switch off and back on) to clear code A8305. No separate reset procedure is listed for this code.

Affected models and serial ranges

A8305 appears in our records across 20 Bobcat models. Match your machine by model and serial number.

Model	Serial ranges
E35	SN A93K110001-99999, SN AC2P11001-99999
E42	SN AG3411001-99999
E45	SN AG3G11001-99999, SN AHHC11001-99999
E55	SN ARWM11001-99999, SN ASW311001-99999
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 A3NT10001-12369, 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

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.

Ask the AI about A8305 Or ask the community in the forum

Frequently asked questions

What does Bobcat code A8305 mean?

It means the ACD/RACD controller found voltage on output "D" (controller pin J1 B-25) when it had not commanded that output on, indicating a short to battery voltage somewhere in that circuit. The controller disables output "D" until the fault is repaired.

Will my attachment stop working with code A8305 active?

Yes. Once A8305 sets, the ACD/RACD controller disables output "D", so whatever attachment function that output controls will not operate until the short is repaired and the code is cleared.

How do I clear code A8305 after repair?

Cycle the key switch off and back on. That is the only clearing step listed for this code; there is no separate reset procedure beyond a power cycle.

What is the difference between A8305 and A8306?

A8305 is output "D" shorted to battery voltage, meaning the controller sees unexpected voltage present on the circuit. A8306 is output "D" shorted to ground, an opposite electrical fault where the circuit is pulled low instead of high. They require different checks: A8305 points to a wire or solenoid picking up battery voltage, while A8306 points to a wire or component grounding out.

How is A8305 different from A8307?

A8307 is an open circuit on output "D", meaning the controller sees no continuity where it expects a working circuit. A8305 is the opposite condition: voltage is present on the circuit when it should be off, due to a short to battery.

Why does my A8305 code come and go instead of staying on?

Bobcat notes that A8305 can be intermittent. If the code isn't active when you test, the cause may be a loose connection, corrosion, or a pushed-back pin in the connectors rather than a constant hard short. These intermittent faults can be harder to find and may need a wiggle test or thorough connector inspection.

Which Bobcat machines can show code A8305?

A8305 applies across Bobcat compact excavators and loaders equipped with ACD/RACD attachment control, including the E35, E42, E45, E55 excavators and the S510 through S770 skid-steer loaders and T550 through T870 compact track loaders.