Automower lift, tilt or collision alarm on a flat lawn

The models differ: a 305 from 2014, a 310, a 320, and NERA models. The display messages are given by their English meaning.

For what Husqvarna's manual says each of these alarms means, and what to do, see the fault and error message reference.

What the reports have in common

• Lift alarm: six owners. A 305 owner saw error 15, which another poster explains as the lift sensor tripping, once; a second 305 owner saw it repeatedly on flat lawn, even with the newest software. Two 310 owners and a third whose model is not stated had "robot lifted" several times a day with the mower found stopped mid-lawn¹⁴. A 450X owner got "lifted" on a perfectly flat lawn in March 2026⁷.
• Tilt or "upside down" alarm: five owners. A 430X NERA owner met "mower tilted" or "slope too steep" regularly on a flat lawn, on firmware 54.2. A 410XE owner and a small NERA owner say they have the same. A 320 owner met "upside down" and then "tilt sensor problem" after three weeks of normal mowing²⁵. A 315 owner in 2026 found the mower stopped with "upside down" often, and only on one patch of lawn⁸.
• Collision alarm: two owners. A 430X NERA stopped with "collision" a few metres after the cutting deck started, free on the lawn, and again after every restart; another 430X NERA owner had many collision stops after a heat wave, with the front obstacle detection apparently not working³⁶.
• It built up. The tilt fault of the 430X NERA owner went from none, to now and then, to four or five times a day over ten weeks². The 320 owner's eased to one return in four, vanished for a month, then came back in 2026 at nearly every start⁵.
• One patch of lawn. The 315 owner has about 1,500 m² and the alarm comes only on one patch of 5 to 6 m², where the grass is greener because the septic drains lie underneath and the lawn is otherwise dry. Pressing OK sends the mower on until the next time. The owner has seen on the forum that this can herald a main-board fault and asks how to recalibrate the tilt sensors; the thread has no reply⁸.

What fixed it, and what did not

A part replaced: four owners, one of them for two days. A 305 owner whose expert menu showed the lift sensor stuck at YES until a restart replaced the front lift-sensor board with its cable, says it has run fine since, and quotes about 40 euro for the parts¹. A 310 owner, after nearly two years of silence in the thread, says he simply replaced the sensor and the problem was solved; which sensor is not stated⁴. A 430X NERA owner had a device board fitted by his dealer and the mower ran without the fault for the two days he reported, on the same software². He adds that, by the pattern, he thinks it is a mechanical or electrical fault that a software update could at most suppress; that is his reading. A 450X owner on a flat lawn replaced the plastic front part with its small magnet, which did nothing, then the small board inside its housing for about 30 euro in all, and the mower worked. A regular said that part is the front collision sensor, not a lift sensor. Some months later the lift error came back and the owner replaced the front-left lift sensor, which looked corroded, and it works again⁷.

A recalibration: one owner, no lasting effect; one owner, a pause. The dealer recalibrated the 430X NERA owner's tilt sensor and the mower reported itself tipped again within three days; the dealer said the electronics would be next². The 320 owner recalibrated the tilt sensor himself after opening and cleaning the mower; it then ran with occasional false alarms and, by 31 August 2024, had gone a month without one, which he cannot explain⁵.

Cleaning: three owners, no effect. One 310 owner blew out the grass with compressed air; a second, with a mower in its seventh year, cleaned the joystick and the rest the same way; the 320 owner cleaned the boards and contacts with alcohol and noticed the front collision sensor was very dirty, even oxidised, though it worked⁴⁵. A regular tells the 2026 collision owner to clean the front collision magnet and the joysticks, since grass debris and metal particles often interfere⁶. That owner cleaned the front and removed some grass; no result is posted⁶.

A main board, judged dead: one owner, who gave up. After opening the 320, reseating every cable, disconnecting every sensor, fitting a new battery and cleaning everything, the owner still had "tilt sensor problem" nearly every start, and judged the main board dead. He puts the board at about 350 euro plus fitting, and bought a different brand of robot instead⁵. A regular quoted the 320's technical manual as placing the tilt sensor and the rear wire sensors on the main board, and saying sensors cannot be repaired and the board is replaced⁵. That is a poster quoting a manual.

A restart: two owners. The 305 owner who saw error 15 once restarted the mower and it carried on¹. The 320 owner says that at first it was often enough to leave the message and restart, and that a gentle tap or two sometimes cleared a false "upside down"⁵.

What owners heard, unconfirmed

• A 410XE owner says Husqvarna e-mailed him that an update in calendar week 24 or 25 of 2024 would fix the tilt error. The 430X NERA owner's dealer fitted a board about then, and no one reports whether the update came or helped².
• One 305 owner's dealer ran a check that passed everything, though the owner's own look at the expert menu showed the sensor stuck¹. That is one dealer on one day, in 2016.
• A regular tells the 430X NERA owner there is an Info, Sensors function in the hidden menu, while another poster says that on the NERA models the hidden menus cannot be reached "to his knowledge".⁶
• One 305 owner, with no children or pets, wondered about fixing the lift-sensor magnet to the housing so the alarm cannot trip¹. No one reports doing it, and we do not suggest it: that alarm is there for the case where the mower is lifted.

What's unknown

• A single cause. A lift board, a sensor, a device board and a main board each appear once, on different models and decades.
• That any software update fixes it. One owner was told one was coming; none reports the result.
• That cleaning fixes it. Three owners cleaned without effect and one is silent.
• That "tilt sensor problem" means the tilt sensor. A regular in the thread doubts the translation of the message, and the 320 owner found it came with every sensor disconnected.
• How common it is. These are the owners who posted, not a count of mowers.