[marc x]

I am looking to buy a used RDC control module from craigslist. The seller says that his "15 x3 had flipped upside down and the insurance totaled it out.
Since I have new tires and my tmps sensors all show normal battery life, but I get RDC malfunction from time to time, I would like to buy the cheaper used one to see if that will remedy the problem.
So, if I purchase this RDC module, will I need to flash the entire ECU to code it in? Or will I just be able to add the module via is serial in the configuration file?? I only see that you can activate or deactivate but nothing in the guide made easy for adding used, pre owned RDC antenna/module.