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Troubleshooting

Xiaomi M365, 1S, Pro 2 and Mi 3: error 10 or error 21 communication fault on the display

On the Mi Electric Scooter, Xiaomi says error 10 is abnormal Bluetooth communication and error 21 is a battery communication fault, paired with a 6 km/h limit. Both go to after-sales, after a few safe checks.

Last edited Nov 8, 2026 by Pedalwise team Edit History Add a subpage

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Battery and electrical safety. Lithium-ion batteries can catch fire if they're damaged or charged wrong. Never open a battery pack, and stop using any battery that's swollen, hot, wet or smells burnt. Every edit to this page is checked by a second person before it goes live.

Parts

Your scooter shows 10 or 21. With 10, Xiaomi links the code to the four battery lamps on the dashboard staying lit. With 21, Xiaomi's page pairs the alarm with the scooter being held to about 6 km/h. Xiaomi's support pages say error 10 is abnormal Bluetooth communication (Xiaomi error 10 FAQ) and error 21 is a battery communication fault (Xiaomi error 21 FAQ), and both send you to after-sales service. The pages are written for the Mi Electric Scooter line rather than one model. The short answer: do the safe checks below, then book service, because both fixes involve the dashboard board or the battery.

Error 21 involves the battery's own electronics. Never open, rewire or bypass anything in the battery pack, and don't try to change the speed limit. Have a service center or shop diagnose it.

Most likely cause

  • Error 10: the Bluetooth link inside the scooter isn't working. Xiaomi gives only the meaning and a service referral (Xiaomi error 10 FAQ). Its general FAQ adds that if the dashboard has no light, you should check whether the connection cable in the stem is loose (Mi Electric Scooter FAQ).
  • Error 21: the controller can't read the battery's management board. Xiaomi gives the meaning and a service referral (Xiaomi error 21 FAQ).

Other causes to rule out

  • A deeply discharged battery: Xiaomi's 1S, Lite and Pro 2 FAQ says long storage can drop the battery into protection, and a deeply discharged battery must be replaced while a shallow one can be recovered by charging (1S and Pro 2 FAQ). See Xiaomi M365 won't charge.
  • Overheating: the same FAQ says a red temperature light means the battery is too hot. Let it cool.
  • A different code: count the beeps. Xiaomi counts a long beep as 10 and a short beep as 1 (Mi Electric Scooter FAQ). Error 10 is one long beep, error 21 is two long and one short.

How to confirm

  1. Count the beeps or read the display, and write the code down.
  2. Charge fully with the original charger, then power on again.
  3. Power off for a minute and back on.
  4. For error 10, check for app connection problems. Xiaomi's FAQ says pressing the brake and throttle fully together and then restarting clears the Bluetooth password, which can help if the app won't pair.
  5. For error 10, fold and unfold the stem slowly with the scooter on and watch whether the code changes. That points to the stem cable.
  6. Note whether the scooter got wet or was dropped before the code appeared.

Fix options

Charge, cool and restart (easy)

This clears some one-off faults. If the code returns, stop and book service.

Dashboard board or stem cable replacement (moderate to pro, error 10)

A service center will check the stem cable and the dashboard. Xiaomi's route is after-sales service through the Xiaomi contact page.

Battery service (pro, error 21)

Battery communication faults are diagnosed by a service center or a shop with the right tools. Xiaomi's general FAQ says not to remove the battery yourself, because it voids the warranty and exposes circuits that can shock you (Mi Electric Scooter FAQ).

Parts

  • Dashboard board (service fitted, error 10)
  • Battery (service fitted, error 21)

When to get a pro

Book service for any error 21, for error 10 that survives a restart, or if the battery feels hot, smells, or looks swollen. See battery won't charge, display blank or flickering and when to call a pro.

Sources

Stuck after these checks? Find a shop near you.

Need a pro?

If these steps didn't fix it, find a shop near you in our partner network. For battery or wiring trouble, look for shops marked Battery and electrical.

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