Bobcat A8407 (84-07) Fault Code: ACD/RACD Output “E” Open Circuit
Also shown on the panel as 84-07 · Also called ACD Output ‘E’ Open Circuit
ACD/RACD Output “E” Open Circuit · ai-assisted, editor-reviewed · Last updated 2026-07-13
TL;DR
A8407 (panel display 84-07) sets when the ACD/RACD controller can't detect the solenoid wired to output "E" on controller pin J1 B-26 or its return wire on pin J1 A-26. The controller disables output "E" until the open circuit is found and fixed.
Medium severity. Output "E" is disabled when this code is active, so whatever attachment function or solenoid runs off that output will stop working. This won't damage the machine, but it will stop attachment functionality tied to that output until repaired.
What does Bobcat error code A8407 mean?
A8407 is set by the Attachment Control Device / Remote Attachment Control Device (ACD/RACD) controller when it loses continuity to the solenoid connected to output "E". The controller monitors this circuit through controller pin J1 B-26 (the output side) and controller pin J1 A-26 (the return side). If either leg opens up, the controller can no longer confirm the solenoid is present and wired correctly.
When this happens, the controller disables output "E" entirely as a protective measure. That means whatever attachment function depends on that specific solenoid output will not operate until the fault is cleared and repaired.
This is strictly a wiring/circuit detection code on the attachment control side. It does not indicate a hydraulic pressure problem or an engine fault, just a broken or interrupted electrical path to one solenoid output.
Common causes of A8407
- Output "E" wire (controller pin J1 B-26) or its return wire (controller pin J1 A-26) is open (broken, disconnected, or cut).
- The output "E" solenoid itself has failed or is not making a proper connection.
- The ACD/RACD controller has an internal fault.
- Moisture, corrosion, or pushed-back pins in the ACD/RACD controller connectors, the mainframe harness, the attachment control harness, or at the output "E" solenoid connector.
- Intermittent connection issues: loose connections, corrosion, pushed-back pins, a marginal controller, or harness damage, alone or in combination. If the code isn't active at the time of testing, the root cause may not be found on that visit.
How to troubleshoot Bobcat A8407: first checks
- With the key switch / run-enter switch on, check for the active code and try to reproduce it by wiggling harness connectors near the ACD/RACD controller and the output "E" solenoid.
- Inspect the ACD/RACD controller connector, mainframe harness connectors, and attachment control harness connectors for moisture, corrosion, or pins that have pushed back out of their sockets.
- Check the wiring from controller pin J1 B-26 to the output "E" solenoid, and the return wire from controller pin J1 A-26, for continuity. Look for chafed, pinched, or broken wire along the harness run.
- Inspect the output "E" solenoid itself and its connector for damage, corrosion, or a poor connection.
- If the code is not currently active, treat it as intermittent: recheck all connectors for looseness or corrosion since the fault may not reproduce during a single test.
How the code clears
Cycle the key switch (power) off and back on after the repair is complete. No separate clearing step is listed beyond cycling power.
Affected models and serial ranges
A8407 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 |
Frequently asked questions
What does Bobcat code A8407 mean?
It means the ACD/RACD controller can't detect the solenoid wired to output "E", either because the output wire (controller pin J1 B-26) or the return wire (controller pin J1 A-26) is open. The controller disables that output until it's fixed.
Will A8407 stop my machine from driving or lifting?
No. This code only affects the attachment output "E" circuit. It disables that specific solenoid output, but it does not by itself affect drive, steering, or lift functions unless those happen to be wired through the same output.
How do I clear code A8407 after I fix it?
Cycle the key switch off and back on. That's the only clearing step listed for this code.
Why does A8407 keep coming and going?
Intermittent A8407 codes are usually caused by loose connections, corrosion, or pushed-back pins in the connectors rather than a fully broken wire. If the code isn't active when you test, you may not find the cause on that visit, so recheck all connectors carefully and look for signs of moisture intrusion.
Which Bobcat machines can show code A8407?
This code applies to the ACD/RACD-equipped Bobcat E35, E42, E45, E55, S510, S530, S550, S570, S590, S630, S650, S750, S770, T550, T590, T630, T650, T750, and T770 models.
Is A8407 the same as a solenoid failure?
Not necessarily. A8407 points to an open circuit, which can be a bad solenoid, a broken wire, a bad connector connection, or even an internal controller fault. You need to check the wiring and connectors first before assuming the solenoid itself is bad.