Juddering brakes abs light on

Get them fixed.
get is serviced
brakes are not something to ignore, get it at least inspected.
juddering, when>? on ice? with ABS>
or on grass,sand ,dirt or my joke on banana peels?
IF the ABS stays on, there is a problem.
but might be just bad brakes, the ABS is kinda stupid, it dont ,now the brakes are bad, only that they act odd, for ANY REASONS.
Get the brakes (actual) checked, linings, leaks, sticking calipers. or pistons in side or slider, so warped rotor.s
if the ACTual brakes are good, then we test the ABS.
in fact we scan it first to see if is catastrophic errors
LIKE
front right sensor IS DEAD> (oops the wires are cut)