BMW C 650 GT Rider's Manual page 148

ASC intervenes unnecessarily, too often or too soon.
11
Possible cause
146
Tyres changed and tyre radii altered
Tyre pressure front or rear too low; tyre pressure
or load changed
No propulsive drive on very loose surfaces (e.g.
sand or snow)
Loss of the adaptation values for the tyre radii in
the digital engine electronics (DME) after software
update
z
https://www.motorcycle-manual.com/
Rectification
Calibrating ASC ( 60).
Checking tyre pressure (
Switch off ASC if the stretch of road you are on is
in very bad condition (
Calibrating ASC ( 60).
108).
58).