ABS, ESP, BAS lights

[cingroomer]

A couple weeks ago while backing up very slowly, my husband caught the front bumper on a piece of bolt sticking up from one of those cement stops. Well, it tore the bumper (we later found out it had already been repaired) At the same time, the ABS, BAS lights came on. Since then, they go off and on at random. Sometimes, they will be off for three days, then there they go again. Usually they go on while backing up and lightly tapping the brake. We do the turning the wheel thing like the book suggests, then they are off again. Sometimes, its just off on its own the next time we start the car. Any suggestions here. I have got to think it had to be something that happened when the bolt caught the bumper. BTW, since then, we have had the car aligned and tires all rotated and balanced (the proper way since the directional tires were on wrong). Any suggestions here, those little lights are driving me crazy.