PCM is the power control module. How did you come to the conclusion it was your PCM? I seriously doubt that your battery drain is the PCM. It is much more likely to be a short somewhere in the circuitry. Here are some good steps on how to find it so you don’t have to guess and waste a bunch of time & money.
http://www.wikihow.com/Find-a-Parasitic-Battery-Drain
http://www.wikihow.com/Find-a-Parasitic-Battery-Drain