As
mr. singh rightly says....
have the codes read... no point in guessing what MIGHT be the cause without knowing which area could be at fault. it could be as simple as a sensor, or a switch. worse case scenario, wiring or ABS unit
Checking anything else out without the necessary equipment is time
wasting unless you know exactly what your looking at or for. HOWEVER,
having said that, the one thing that is simple to check is the fusible
link that is at the battery. It is the big block under the red cover and
as already stated, one of the 4 fuses in it is associated with the ABS.
Grab a circuit tester and check for continuity across each fuse.
Other than that, wait till your appointment with the Smart 'indie'.