Segway error code 21: Battery (BMS) communication fault

What does this code mean?

The controller cannot talk to the battery management system (BMS). The cable and connector between battery and controller are inspected, including for water or corrosion. If the fault stays, the battery is replaced.

Which models show it?

Models that show two-digit codes, such as Max G30 / Max G2, the E series (E2, E2 Pro), the F2 series and the ZT3 Pro

Safe checks you can do yourself

1. Switch the scooter off, wait 10 seconds and switch it on again; if the code stays, note it down.
2. Check the fault and battery details in the Segway app and attach a screenshot to your service request.
3. Don't open the deck, battery or controller, and don't unplug cables yourself.

If the code stays after these checks, stop using the scooter and open a service request.