if its this age - do you 100% have the reluctor ring on the inner part of the front left disc and the small wire to the wheel speed sensor... and you get a separate ABS button on the left switch gear
if it has ASC - it will ALSO have a separate ASC button beside the info button - a very rare option - and on the LCD cluster screen it will have a flashing A top right. When you press the ASC button it will swap to a better flashing S - if its working - once ridden 10 yards, it will either revert to a solid non flashing A or S another press displays nothing and its OFF
or ride up the road and stand on the back brake - if you get a crude massage on your foot its got functioning ABS, if it skids, some moron has messed with it - if it was there, but broken the red light would be on all the time
I suspect its a std bike with neither toy - or he could have turned them off with motoscan if its just broken like they always do - the brushes stick and the ESP motor doesn't run - same unit as the cars, but the ESP pump only manages the linked brakes - perfectly fixable - with a hammer or remove the pump and clean it - but that's involved