Segway GT1/GT2 error code 5: Water detected in stem top

What does this code mean?

Water was detected at the top of the stem. Stop using the scooter and contact the service.

Which models show it?

Segway SuperScooter GT1 and GT2

Safe checks you can do yourself

1. Switch it off, don't charge it, and keep it somewhere dry, away from buildings.
2. 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.