What does this mean
 

Hello everyone, I have a 95 sonoma and have recently noticed my brake light indicator comes on and then off again from time to time. Recently it stays on more then off, but every now and then it will flash "code style" 3 times then pause and repeat over and over again. The brakes seem fine and I've had a guy look at them. The guy said it was probably the ABS system, but he didn't have a code book for my truck. The suspense is getting the better of me and I hope you guys can help.

that usually means your truck recognizes a generic problem. Just go to a franchise parts store and rent a code reader and check your truck in the parking lot.