BMW C 400 X Rider's Manual page 186

ASC intervenes without it being necessary, too often or too early.
13
Possible cause
184
Different tires fitted and tire radii changed
Insufficient tire pressure in front and rear; tire
pressure or payload changed
No propulsion on very loose surfaces (e.g. sand or
snow)
Loss of adaptation values for the tire radii in the
Digital Motor Electronics after a software update
z
https://www.motorcycle-manual.com/
Remedy
Calibrating ASC ( 71).
Checking the tire pressure (
Switch off ASC to overcome extremely poor road
surfaces ( 69).
Calibrating ASC ( 71).
144).