Brake Caliper Locked up on Highway!

[gregwx5]

On Saturday I was driving down to the dealership (BMW Gallery Norwood) to pick up a new cd changer...while driving my steering wheel started to shimmy left and right...I though it was the road so I changed lanes and it progressively got worse...pulled over checked tires for flats and then noticed my front right brake was very hot....I knew what the problem was immediately because last year after buying the X my left front caliper siezed on me...when i was doing 85 in cruise control....Luckily the new calipers were covered under CPO and they gave me both new front rotors and pads both times... I also had a problem with the "engine failsafe mode" coming on along with the dsc and brake light...they found that to be a faulty wheel angle sensor and they recoded it...anybody know exactly what the wheel angle sensor actually does? Well that was my Xciting weekend!