known-issue

Fault 1028 ("drivetrain motor error detected"): benign when wheel-stuck-triggered, per Mammotion

Models covered: YUKA, YUKA mini (also reported, less specifically, on LUBA)
Affects: Robot body — not the app
First reported: 9 June 2025
Last updated: 7 September 2026
Status: Manufacturer-acknowledged

Robot body — not the app. See our app vs. firmware vs. RTK guide if you're not sure which one you're dealing with.

What this page is: fault 1028 is not documented in any of Mammotion's official manuals (see the fault-codes reference) — it's a community-observed, app-surfaced code. Multiple owners have hit it under the same specific trigger, and Mammotion support gave an official (if vague) explanation in-thread. A separate, more severe pattern is a single report so far and is not the same issue; see the note at the bottom.

The common trigger: a wheel gets physically stuck

Fault 1028 ("Fehler im Fahrwerksmotor erkannt" / drivetrain motor error detected) has been independently reported by owners of a YUKA 1000 with the grass-catcher sweeper attachment, a YUKA mini 500, and — per a long-standing forum regular, though without a specific model or date — on LUBA units too¹. In the two detailed reports, it appeared right after a wheel got physically stuck: once against the sweeper's grass-catcher basket, once during a general stuck-wheel event. Fault 363 ("Phasenstrom Überstrom des linken Radmotors" — left wheel-motor phase-current overcurrent, indicating a blocked wheel/hub) logged at the exact same moment as 1028 in one owner's error log, supporting a stuck-wheel/overcurrent origin rather than a distinct drivetrain hardware fault¹.

Mammotion's official response

Contacted directly about a recurring 1028 that a physical repair (motor/hub replacement) did not fix, Mammotion support replied: "Nach unseren aktuellen Untersuchungsergebnissen handelt es sich um ein gelegentlich auftretendes Problem, das durch Faktoren wie Umgebungsbedingungen, Spannungsschwankungen oder vorübergehende Kommunikationsstörungen verursacht werden kann. Die Sicherheit des Geräts wird in der Regel nicht beeinträchtigt." (an occasional issue that can be caused by factors like ambient conditions, voltage fluctuations, or temporary communication interruptions; device safety is generally not affected)¹. That reply is non-committal about a precise cause, and doesn't explain why a hardware repair failed to resolve it for that owner, but it does confirm Mammotion doesn't consider isolated 1028 events, on their own, a safety issue requiring repair.

If you're hitting this after a wheel gets stuck (in a grass catcher, dense grass, a small hole, etc.): per Mammotion's own reply above, an occasional 1028 in this situation is expected and not necessarily a hardware fault. Free the wheel, restart, and only escalate to support if it recurs without a stuck-wheel trigger or blocks the mower from moving at all afterward.

Not the same case: a separate report describes a persistent, unrecoverable 1028 with no subcode, appearing after several months of winter storage (not triggered by a stuck wheel), on a LUBA 2 AWD 3000-class unit that had run 172 problem-free hours the prior season. Repeated restarts didn't clear it, and the owner was told to ship the whole unit back for repair. This is a single report so far and reads as a different failure mode from the stuck-wheel cases above (no trigger event, no self-recovery, needed a full return); tracked separately in tracked-leads.md rather than folded into this page.

Sources

FORUM 1. roboter-forum.com: Fehler im Fahrwerksmotor erkannt (1028)