2001 Cavalier TRAC off, ABS, service light all on

Ok I have a cavalier and it runs pretty good I put many miles on it and just recently I have been having problems with my ABS and TRAC off and service light all on and the service with the wrench light is the one that lights. Anyways they are always on and checked all wheel sensors with ohm meter and seem to be fine checked fuses and everythign else. Now when my wife was driving the car she said that the brakes applied them self and then all of the lights came on and they went out and a few days gone by and then came on and stayed on I cant stand to look at all the lights on it looks like a damn x mas tree lit up can anyone help? I heard that the AIT sensor might be bad is this true? Help ASAP!