Xiaomi M365, 1S, Pro 2 and Mi 3: error 18, motor gives no power when you press the throttle

The scooter powers on and the display looks normal apart from 18, or you hear one long beep and eight short ones, and the motor gives nothing when you press the throttle. On the Mi Electric Scooter, code 18 points to an exception in the Hall sensor system and needs after-sales service (Xiaomi error 18 FAQ). This covers the Mi Electric Scooter line rather than one model, so it applies to the M365 family scooters that use this code style. The short answer: the motor's Hall sensors or their wiring have failed, and the fix is a motor repair or a new motor wheel.

Most likely cause

Hall sensors sit inside the hub motor and tell the controller where the motor is in its rotation. Without them the controller can't drive the motor, which is why there is no motor output (Xiaomi error 18 FAQ). A Hall signal that won't switch is either a wiring problem for that sensor or a failed sensor (Grin hall sensor testing guide). On a scooter, the part of that wiring you can see is the motor cable between the axle and the deck.

Other causes to rule out

• Not rolling yet: the throttle won't engage below 5 km/h, so push off first (Mi Electric Scooter FAQ).
• Error 14: a throttle fault, not the motor. See Xiaomi error 14.
• Error 10 or 21: communication faults. See Xiaomi error 10 or 21.
• Control board: a throttle that does nothing above 5 km/h can also be a failed control board, which needs service.

How to confirm

1. Count the beeps at start up. A long beep counts as 10 and a short beep as 1, so one long and eight short is 18 (Mi Electric Scooter FAQ).
2. Push off above 5 km/h and try the throttle once more, so you know it isn't the kick start speed.
3. Power off and spin the motor wheel by hand. Note any grinding, roughness or a wheel that wobbles. An unstable wheel can mean a misplaced inner tire or a faulty motor.
4. Look at the motor cable where it leaves the axle for cuts, a flattened section, or a cable stretched by a loose axle.
5. Think back to rain or puddles. These scooters are rated IP54, but don't ride them in the rain.

Fix options

Use Xiaomi after-sales service (easy for you)

Xiaomi's own answer for error 18. Start with the Xiaomi contact page, especially if the scooter is under warranty.

Swap in a new motor wheel (moderate to pro)

Replacing the whole motor wheel replaces the Hall sensors and the cable in one go. It means removing the wheel, routing the new motor cable to the controller and reconnecting it. Do it only if you're comfortable working inside the deck without touching the battery, otherwise have a shop do it. Buy a motor listed for your exact model.

Repair the motor cable or Hall sensors (pro, needs soldering and electrical experience)

A shop can open the motor, replace the Hall sensors, or repair a damaged Hall wire. Defective hall sensors are a common failure, and Grin's troubleshooting resources include a repair guide. This is usually cheaper in parts than a new motor but takes skill and time, so get a quote for both.

Parts

• Motor wheel for your exact model, or Hall sensors fitted by a shop

When to get a pro

Get help for any motor opening, soldering or cable splicing, if the cable is visibly damaged, or if the scooter got wet before the code appeared. See motor cuts out, repair or replace and when to call a pro.

Sources

• Xiaomi error 18 FAQ, mi.com
• Mi Electric Scooter FAQ, mi.com
• Grin hall sensor testing guide, EBIKES.CA
• troubleshooting resources, ebikes.ca
• Xiaomi contact page, mi.com

Stuck after these checks? Find a shop near you.