Bobcat W3251 (32-51) Fault Code: ACS Lift Actuator Short to Battery (Error On) (ACS Only)
Also shown on the panel as 32-51 · Also called ACS (AHC) Lift Actuator Short to Battery, ACS Lift Actuator Short to Battery (Error On) (SJC Only)
ACS Lift Actuator Short to Battery (Error On) (ACS Only) · ai-assisted, editor-reviewed · Last updated 2026-07-13
TL;DR
W3251 (panel code 32-51) sets when the ACS controller sees the lift actuator signal wire voltage go above 4.9 volts, higher than the 5.0-volt supply the controller sends the sensor. When this code is active, lift and tilt functions are disabled until it clears.
High severity. Lift and tilt are disabled while this code is active, which stops normal loader operation. It is not an engine-damage emergency, but the machine cannot do lift or tilt work until the fault is fixed and cleared, so it should be diagnosed before returning the machine to service.
What does Bobcat error code W3251 mean?
W3251 is set by the Advanced Control System (ACS) controller, which also may be referred to as AHC or SJC depending on the machine's control setup. The controller sends a 5.0-volt reference signal out to the lift actuator sensor and reads a return signal on a dedicated signal wire. If that returned voltage climbs above 4.9 volts, the controller interprets this as a short to battery voltage on the signal circuit and sets W3251.
Because the lift actuator sensor tells the controller where the loader arms are positioned, a bad signal reading is treated as unsafe to act on. The controller responds by disabling both lift and tilt functions until the fault is resolved, which is why this code stops work immediately rather than just logging a warning.
Depending on model and harness version, the exact wire numbers involved differ (for example 4670, 3980, 1610, 5980, 1530, or 2630 among others), but the fault logic is the same across all of them: a signal or supply wire is seeing more voltage than it should.
Common causes of W3251
- Lift actuator needs calibrating
- 5-volt supply wire shorted to supply voltage (wire numbers vary by model, examples include 1610, 5980, 1530, and 5870)
- Signal wire shorted to supply voltage (wire numbers vary by model, examples include 4670 and 3980)
- Ground wire open (examples include 2630, 2980, and 2670 depending on model)
- Faulty lift actuator
- Faulty ACS controller
- Moisture, corrosion, or pushed-back pins in the ACS controller connectors, lift actuator connector, or ACS wiring harness
- Intermittent fault: if the code is not active at the time of testing, the root cause may not be identifiable right away. Likely culprits are still loose connections, corrosion, pushed-back pins, the controller, the harness, or a combination of these
How to troubleshoot Bobcat W3251: first checks
- Confirm the code is active with the key switch in run/enter position, since that is the condition required for the controller to set W3251
- Inspect the ACS controller connectors and the lift actuator connector for moisture, corrosion, or pins that have pushed back out of their sockets
- Check the 5-volt supply wire and signal wire circuits for signs of chafing, pinching, or contact with a source of battery voltage that could cause a short
- Verify the ground wire for the lift actuator circuit has continuity and is not open
- Run or check whether the lift actuator needs calibrating, since this is listed as a possible cause on its own
- Test the lift actuator itself for proper sensor output if wiring and connectors check out clean
- If the code is not currently active, wiggle-test harness connectors and check history for intermittent occurrence before condemning the controller
How the code clears
After completing the repair, cycle power (turn the key switch off and back on) to clear the code. No separate clearing step is listed beyond a power cycle.
Affected models and serial ranges
W3251 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 W3251 mean?
It means the ACS controller detected voltage above 4.9 volts on the lift actuator's signal wire, which the controller reads as a short to battery voltage. Since the controller normally supplies only 5.0 volts to that sensor circuit, this reading is out of range and triggers the fault.
Why did my loader lose lift and tilt after this code appeared?
The ACS controller automatically disables lift and tilt functions any time W3251 is active, since it can no longer trust the position feedback from the lift actuator. This is a built-in protection response, not a separate mechanical failure.
Can I clear W3251 myself?
Once the underlying wiring, connector, actuator, or controller issue is repaired, clearing the code just requires cycling power (turning the key off and back on). No special reset tool or procedure is listed beyond that.
Which Bobcat models can show code W3251?
This code applies across a range of Bobcat skid-steer and compact track loader models, including the S510, S530, S550, S570, S590, S630, S650, S750, S770, and the T550, T590, T630, T650, T750, T770, and T870.
Does calibration alone fix W3251?
Sometimes. A lift actuator needing calibration is listed as one of the possible causes, so recalibrating the lift actuator is worth trying early on, especially if wiring and connectors check out fine. If the code returns after calibration, the problem is more likely wiring, the actuator itself, or the controller.
What wire numbers should I check for this code?
The exact wire numbers depend on the machine and harness version. Signal wires seen include 4670 and 3980, 5-volt supply wires include 1610, 5980, 1530, and 5870, and ground wires include 2630, 2980, and 2670. Check your machine's wiring diagram to confirm which numbers apply to your unit.
Is W3251 an intermittent fault?
It can be. If the code is not active when you test the machine, the root cause may not show up right away. In that case the likely culprits are still loose connections, corrosion, pushed-back pins, the controller, or the wiring harness, just not currently triggering the fault condition.