My ABS light is on and stays on?

ABS and traction control system share same wheel speed sensors. It may have a failing speed sensor...you will need to take it to a shop that has capable diagnostic equipment to do proper diagnosis. The shuttering could be the abs system working when it should not be due to failed speed sensor or simply a badly warped brake disc.

have abs codes scanned and post so we can adv. the frt brake shimmy is most likely warped rotors.