my ABS light is on and mainly after start ups on 2004 Isuzu Ascender

sometimes i fill my brakes flutter when coming to a stop (even a slow stop) like it would if i came to a fast stop.

Asked by for the 2004 Isuzu Ascender
Sounds just like a wheel speed sensor failure.When these go bad the #1 symptom is abs brake actuation at a slow stop.You just need to get it scanned to find out which one,and when you remove the old sensor inspect the ring to make sure it is not cracked,bent or misaligned.