Hiboy S2, S2R, S2 Pro, S2 MAX, KS4, KS4 Pro, S2R Plus and MAX Pro error codes · Hiboy S2 series

E9 Error on Hiboy S2 series

What it means + how to fix it From the brand

Quick answer

E9 on the Hiboy scooters (S2, S2R, S2 Pro, S2 MAX, KS4, KS4 Pro, S2R Plus, MAX Pro) means “Controller failure.” Most likely cause: a fault in the controller (the scooter's motor control board). Try this first: switch off and restart.

Try this first

Free, and each takes under 5 minutes.

Switch off and restart
Write down the code and when it happens

In plain English

The controller sends battery power to the motor. This code means it found a fault in itself. That's a support job.

Step-by-step checklist

Work from the top. Steps go from free and easy to shop jobs. Switch the scooter off before touching any connector. Tick each step as you go. Your progress is saved on this device.

1Switch off and restartFree Turn the scooter off, wait 30 seconds, then turn it back on. If the code clears, note what you were doing when it appeared, in case it comes back.
2Write down the code and when it happensFree Take a photo of the display and note when the code appears: at switch-on, when you set off, on hills, in rain or while charging. Support will ask for this.
3Contact support or a service centerShop job If the code stays after these checks, stop riding and contact the brand's customer support or an authorized service center. Don't open the deck, battery, controller or motor: most scooter batteries and controllers aren't user-serviceable.

Still not fixed?

Pages to try next:

All Hiboy scooters (S2, S2R, S2 Pro, S2 MAX, KS4, KS4 Pro, S2R Plus, MAX Pro) codes

When it's time for a shop: if you've worked through every step and the problem is still there, contact the brand's support or an authorized service center. Bring your notes on when it happens, plus the code.

Words on this page: Controller