GMC Repair: truck body controller, radio module, xm radio

Question
My truck keeps killing the battery. I get.35 amp draw with the key off. I pull fuses and the one that is pulling all the current is the truck body controller battery feed. What all does this control and do you have ideas what may be wrong? I feel I have a short somewhere but don't know what all to check.

Answer
BCM could be shorted internally, that or you have an onstar module or XM radio module that is not powering down, if you can monitor the draw, try unplugging the VCIM and then the XM radio module then the BCM, if it is one of those you will see the draw go away.  Would need more vehicle info to help you locate the parts I am talking about