Bobcat H3028 (30-28) Fault Code: Auxiliary Controller Memory Failure
Also shown on the panel as 30-28 · Also called Controller Memory Failure
Auxiliary Controller Memory Failure · ai-assisted, editor-reviewed · Last updated 2026-07-13
TL;DR
H3028 (panel form 30-28) means the software loaded into the auxiliary controller is corrupted. It sets whenever the key switch or run/enter is on, and it usually points back to a bad software update, a loose programming connection, or corrosion in the connectors between the gateway controller, auxiliary controller, and diagnostic tool.
Medium severity. H3028 does not describe an immediate safety hazard on its own, but a corrupted auxiliary controller can affect functions tied to that controller. Diagnose it before returning the machine to normal work, especially if any auxiliary-controlled function is behaving oddly.
What does Bobcat error code H3028 mean?
H3028, also shown as 30-28 on the numeric panel, is an Auxiliary Controller Memory Failure. It fires when the software that was loaded into the auxiliary controller comes up corrupted rather than the controller running a clean, complete program.
This is a software and communication integrity problem rather than a mechanical failure. It is generally caused by an interruption during the programming process, such as power dropping mid-update, or by corrupted software on the download file or CD used to flash the controller.
The auxiliary controller manages functions on the machine that depend on it, so a corrupted memory image can cause unpredictable behavior in those functions until the controller is reflashed with clean software and the fault is cleared.
Common causes of H3028
- Defective CD or corrupt software download used during a controller update.
- Loose connection between the PC and the gateway controller during programming.
- Interruption of power to the auxiliary controller while a software update was in progress.
- A failing auxiliary controller itself.
- Moisture, corrosion, or pushed-back pins in the gateway controller connectors, auxiliary controller connectors, diagnostic tool connectors, diagnostic tool/ACD connector, or mainframe harness.
- Intermittent conditions from loose connections, corrosion, pushed-back pins, the controller, or the wire harness, alone or in combination, that may not show up if the code is not active at the time of testing.
How to troubleshoot Bobcat H3028: first checks
- Confirm the key switch or run/enter switch is on, since this is the condition the controller needs to display the code.
- Inspect the gateway controller and auxiliary controller connectors, plus the diagnostic tool and diagnostic tool/ACD connectors, for moisture, corrosion, or pushed-back pins.
- Check the mainframe harness for loose connections or damage along the path between the gateway controller and auxiliary controller.
- Verify the software download or CD used for the last update is not corrupted or defective before attempting another flash.
- Make sure power to the auxiliary controller stayed steady during any prior update attempt; do not interrupt power mid-flash on the next attempt.
- If the code is intermittent and not active during testing, treat loose connections, corrosion, pushed-back pins, the controller, or the harness as the likely suspects and recheck them carefully.
How the code clears
Once the repair is complete, clear H3028 by cycling power to the machine. No separate reset procedure beyond a power cycle is listed for this code.
Affected models and serial ranges
H3028 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 H3028 mean?
It means the auxiliary controller loaded a corrupted software image, generally from an interrupted programming session or a bad download or CD.
What is the numeric panel code for H3028?
It shows as 30-28 on machines with the numeric fault panel display.
How do I clear H3028 after fixing the problem?
Cycle power to the machine. That is the listed condition for clearing the code once the repair is complete.
Can a loose connector cause H3028?
Yes. A loose connection between the PC and gateway controller during programming, or corrosion and pushed-back pins in the gateway, auxiliary controller, diagnostic tool, or mainframe harness connectors, can trigger it.
Why does H3028 come and go instead of staying on?
Intermittent H3028 is usually tied to loose connections, corrosion, pushed-back pins, the controller itself, or the wire harness, sometimes in combination. If the code is not active when you test, the exact cause may not be found right away.
Is H3028 dangerous to keep operating with?
It is not described as an immediate hazard, but since it involves a corrupted controller, any function tied to that auxiliary controller should be checked before continuing normal work.
Will reflashing the auxiliary controller fix H3028?
A clean reflash with good software, done without power interruption, addresses the described causes, but you should also check connectors and wiring for corrosion or damage since those can cause or contribute to the failure.