Hey guys I have an 04 GMC 2500hd with the LB7 duramax engine. The other day I fired her up and I noticed the check engine, ABS, parking brake light and service 4wd on the dash. It was in limp mode driving home. Now it wont fire up or even turn over and keeps blowing ignition fuse A every time I attempt to turn it over. It is throwing codes U2106 and U1024. Loss of communication to TCM and faulty TCM. All the research I have done say the TCM is rarely ever the actual cause and it could boil down to Ignition switch, starter, nsbu switch, etc. I doubt it is the starter since I installed a new one about 3 months ago. I just replaced the ignition switch and nsbu switch within past couple days with no luck. I haven’t seen any exposed/rubbed wires anywhere that I can see. I even pulled plugs from TCM and they looked fine. I really don’t want to haul it to a shop to get bent over a barrel and I dont want to spend $500 on a remanufactured TCM or $1800 on a new one without knowing it truly is the cause. I did notice the battery light on and a low voltage reading when I attempted to install my programmer. Could it possibly be the alternator or???? Any help would be greatly appreciated. Im far from a true mechanic but if its something i can solve myself I would much rather. Thanks guys.