Bobcat W3275 (32-75) Fault Code: Interrupted Un-switched Power
Also shown on the panel as 32-75 · Also called ACS (AHC) Interrupted Unswitched Power
Interrupted Un-switched Power · ai-assisted, editor-reviewed · Last updated 2026-07-13
TL;DR
W3275 (panel form 32-75) sets when the ACS (Attachment Control System) controller detects a loss of battery voltage on its unswitched power supply. When it sets, lift and tilt functions are disabled until the fault is cleared. It commonly appears alongside W3265 or M3204.
High severity. Lift and tilt are disabled as soon as this code sets, which stops loader work outright. It is not a safety-critical failure by itself, but the loss of hydraulic control functions means the machine cannot be used productively until the wiring, fuse, and controller are checked.
What does Bobcat error code W3275 mean?
W3275 is an ACS controller fault meaning the controller has detected a loss of battery voltage on the unswitched power circuit that feeds it. The ACS controller manages attachment functions including lift and tilt, and it needs a stable, constant power supply to operate correctly regardless of key switch position.
When the controller sees this power interruption, it disables lift and tilt functions as a protective response, since it cannot reliably control those functions without steady voltage. The code is stored inside the ACS controller and can only be viewed with diagnostic software, it does not show up as a dash message on its own.
This code often shows up together with W3265 (ACS sensor supply out of range) or M3204 (ACS no communication), since all three can stem from the same underlying power or wiring problem feeding the ACS controller.
Common causes of W3275
- Stalling the loader's engine without turning the key off, then restarting with a weak battery
- A blown or faulty fuse (listed variously as FC1 fuse 3, FRC1 fuse 12, or fuse 12 depending on model and platform)
- Supply wire 1180 or 1190 shorted to ground or open
- Ground wire 2260 or 2270 open
- A faulty ACS controller
- Moisture, corrosion, or pushed-back pins in the ACS controller connectors or mainframe harness connectors
- An intermittent fault that is not present at the time of testing, which can involve loose connections, corrosion, pushed-back pins, the controller, the wire harness, or a combination of these problems
How to troubleshoot Bobcat W3275: first checks
- Confirm the key switch is on (run/enter position) and the engine is running, since these are the required conditions for the code to be active
- Check the relevant fuse (FC1 fuse 3, FRC1 fuse 12, or fuse 12 depending on the machine) for continuity and proper seating in its holder
- Inspect supply wire 1180 and 1190 for chafing, shorts to ground, or open circuits along their length
- Inspect ground wire 2260 and 2270 for a solid, open-free connection to chassis ground
- Open the ACS controller connectors and mainframe harness connectors and look for moisture, corrosion, or pins that have been pushed back out of their sockets
- If the code is not currently active, treat it as intermittent and focus on connection points, since loose connections and corrosion are the most likely culprits in that case
- Ask the operator whether the engine was recently stalled without shutting off the key, then restarted on a weak battery, since this is a listed cause
How the code clears
No separate clearing step is listed for this code. Once the underlying power interruption, wiring fault, fuse, or connector problem is corrected, the code should stop being detected on the next key cycle and engine run, though because it is stored in the ACS controller it may need to be checked with diagnostic software to confirm it is no longer active.
Affected models and serial ranges
W3275 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 W3275 mean?
It means the ACS controller has detected a loss of battery voltage on its unswitched power supply. This is described as interrupted unswitched power, and it causes the controller to disable lift and tilt functions until the issue is resolved.
Why did my loader's lift and tilt stop working?
If code W3275 has set, the ACS controller disables lift and tilt as a direct result of losing steady battery voltage. Restoring power to the controller and clearing the fault should restore those functions.
Can I see W3275 on the dash display?
No. This code is stored inside the ACS controller and is only visible when checked with diagnostic software, it does not appear as a standalone message on the operator display.
Is W3275 related to other codes?
Yes, it can appear along with W3265 (ACS sensor supply out of range) or M3204 (ACS no communication), since these can share the same root cause in the ACS power or wiring.
What fuse should I check for W3275?
Depending on the machine and documentation, this is listed as FC1 fuse 3, FRC1 fuse 12, or fuse 12. Check the fuse that feeds the ACS controller's unswitched power for that specific model.
Can a weak battery cause this code?
Yes. Stalling the loader's engine without turning the key off and then restarting with a weak battery is specifically listed as a cause of this code.
What if the code doesn't show up when I test the machine?
If the fault is intermittent and not active during testing, the cause may not be found right away. Focus on loose connections, corrosion, pushed-back pins, the controller, and the wire harness, since these are the most likely intermittent causes.