ABS Module Testing

[Seattleslew]

Good Morning,

Im new to the site and this is my first post here. Ive found a ton of valuable info on the site but am still having some trouble finding the answer Im seeking. We bought an 02 X5 4.4 back in November and about a month ago had the ABS, DSC, and brake lights illuminate for no more than a day or so. They would then go off for a number of days and come back on only to turn off again. When pulling the codes with an OBDII scanner, it returned a code for the left rear wheel speed sensor. The third time this happened,each of these lights were accompanied by an inoperative speedometer.

At this point, I did a bit of research online and found an indy that had the proper diagnostic tools, good customer reviews, and 20+ years experience. I received a call a day after dropping the X5 off to them letting me know that it wasnt actually as simple as a wheel speed sensor and that the ABS module had a "short" in it so the unit needed to be replaced. The advisor went on to say that this would solve my problem once done. I recieved a call back shortly after expecting the vehicle to be ready but instead was informed that the problem had not been resolved and that the 2 rear wheel speed sensors needed replacing.

I say that to say this. The wheel speed sensors are what I figured to be the culprit to begin with so one would assume that the repair would start there, with the less expensive replacement. I understand that the OBDII scan tool is not as comprehensive and that these computer systems can sometimes be finnicky but t the same time have a funny feeling about the ABS module replacement. When picking up the vehicle i asked that the provide me the "shorted" ABS module and they did so with no problem. What I need to know is if its possible to test the old unit in the vehicle w/out having to get the new one reprogrammed again when I put it back in. Ive found the removal/replacement write ups on the site but dont want to jump into testing the old unit unless Im sure I can put the recently replaced one back in with no issues.

Any help by way of suggestion with this would be greatly appreciated.