2001 Chevy S10 ABS and brake light issues

[bigdogdaddy]

I bought a 2001 Chevy S10 with 25k (yeah, really) miles on it from a friend who's dad died. It is like new inside and out. The ABS and brake light come on and stay on most of the time. I bought a code reader and it had an alarm for the ABS control module, one for the ABS relay as well as other brake code issues. I reset the alarm and drove it down the road a few miles (I drove forward) and could not get it to come on. Later I went to town, this time backing out of my driveway and about 10 feet the lights came on. I was wondering if this could be the relay, the module or one of the sensors. It doesn't seem to hurt the drivability, it's just a pain in the rump. I have to admit I don't know much about these new fangled computerized vehicles.

Also, can this module be tested at the auto part's store? Any advice I could get would be appreciated. I hate to buy a new module and then that not be it.

Thanks in advance.