Bobcat H2905 (29-05) Fault Code: High Flow Solenoid Short to Battery
Also shown on the panel as 29-05 · Also called High Flow Solenoid Short To Battery, High Flow Solenoid Short to Battery, High-Flow Short to Battery
High Flow Solenoid Short to Battery · ai-assisted, editor-reviewed · Last updated 2026-07-13
TL;DR
H2905 (panel code 29-05) sets when the auxiliary controller sees battery voltage on the high flow solenoid signal wire 4460 while the solenoid is not commanded on. It points to a wiring short or a solenoid/controller problem in the high flow circuit, not to a mechanical failure of the hydraulic pump itself.
Medium severity. H2905 doesn't shut the machine down, but it disables reliable control of the high flow auxiliary circuit. Running attachments that depend on high flow (mulchers, cold planers, etc.) with this fault active can cause unexpected flow behavior, so it should be diagnosed before using those attachments.
What does Bobcat error code H2905 mean?
H2905 is set by the auxiliary controller when it detects battery voltage present on signal wire 4460, the wire that commands the high flow solenoid, at a time when the controller has not commanded that solenoid on.
The high flow solenoid's job is to let output from the high flow pump join the machine's normal auxiliary hydraulic flow. This added flow is only supposed to be introduced when the front base auxiliaries are engaged. If the controller sees voltage on that signal wire outside of that commanded state, it flags H2905 because it can no longer trust or control when high flow gets added.
This is an electrical/circuit-level fault code about the solenoid's control wiring, not a direct report of a hydraulic pump or valve failure, though a bad solenoid coil can also trigger it.
Common causes of H2905
- Signal wire 4460 shorted to battery voltage
- Return wire 2460 shorted to supply voltage, or shorted to signal wire 4460
- Faulty high flow solenoid
- Faulty auxiliary controller
- Moisture, corrosion, or pushed-back pins in the auxiliary controller connectors, high flow solenoid connector, or mainframe harness
- Intermittent causes that may not be found at the time of testing, including loose connections, corrosion, pushed-back pins, the controller, the wire harness, or a combination of these problems
How to troubleshoot Bobcat H2905: first checks
- Confirm the key switch / run-enter state is on, since that is the condition required for the controller to set this code, then check for the active fault on the display.
- Inspect the auxiliary controller connectors and the high flow solenoid connector for moisture, corrosion, or pins that have pushed back out of their sockets.
- Trace signal wire 4460 for chafing, pinches, or contact points where it could be shorted to battery voltage, especially near the mainframe harness routing.
- Check return wire 2460 for a short to supply voltage or a short to signal wire 4460, since either condition can mimic a solenoid command that was never sent.
- With the connector disconnected, test the high flow solenoid coil itself to rule out an internal short before condemning the controller.
- If the fault is intermittent and not present at the time of testing, wiggle-test the harness and connectors while watching for the fault to reappear, since it may not show up on a static check.
How the code clears
Once the wiring, solenoid, or controller issue is repaired, clear H2905 by cycling power on the machine. No separate reset procedure or scan tool clearing step is listed beyond a power cycle.
Affected models and serial ranges
H2905 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 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, SN A3PH11001-99999 |
Frequently asked questions
What does Bobcat code H2905 mean?
It means the auxiliary controller detected battery voltage on the high flow solenoid's signal wire 4460 when it had not commanded the solenoid on. It usually points to a short in the wiring or a solenoid/controller fault, not a general hydraulic system failure.
What is the panel display number for H2905?
On the numeric panel display it shows as 29-05.
Can I keep operating the machine with H2905 active?
You can generally continue basic operation, but high flow attachments may not behave predictably since the controller can't reliably manage when high flow is added to auxiliary flow. It's best to diagnose the fault before relying on high flow functions.
Which Bobcat models can show code H2905?
It applies across S510, S530, S550, S570, S590, S630, S650, S750, S770, T550, T590, T630, T650, T750, and T770, T870 models equipped with the high flow auxiliary hydraulic option.
How do I clear H2905 after a repair?
Cycle power on the machine after completing the repair. No separate scan tool clear or reset sequence is listed for this code.
What wires should I check first for H2905?
Start with signal wire 4460, checking for a short to battery voltage, and return wire 2460, checking for a short to supply voltage or to wire 4460 itself.
Is H2905 caused by a bad hydraulic pump?
Not directly. The code is about the solenoid's electrical signal circuit. The high flow solenoid, its connector, the auxiliary controller, or the wiring between them are the listed causes, not the pump itself.