Car won't start, possible fob issue

[Blessed]

2006 Infiniti M35. I drove the car as I always do, parked it, and when I went to leave, the car wouldn't start. I've seen other posts with similar issues but no final solutions. Everything works other than the dash lights, the radio, ac, and the fob. The dome lights work, headlights work, doors lock and unlock with the actual key in the door, the battery in the car has been checked and its good, changed batteries in the fob a few times and still nothing. I touched the fob to the push button and nothing. I checked fuses and I put the fob in the key fob port under the dash and still nothing. It made the beeping sound when I put the fob in the port but the light beside the port didnt come on. The beep just lets you know something is in there because I put my altima fob in there and it did the same thing. I only have 1 fob. The car was running fine when I turned it off and it was about an hour later when I went to get back in the car and it wouldnt start. The security light is flashing but when I locked the door with the actual key, the light stayed red. Could the fob have unprogrammed somehow or could it be the key fob port? Any ideas? The car is sitting on a trailer right now. I have unhooked the battery after it wouldn't start too and hooked it back up just to see if it would reset anything. My windows were down when I did this and now they wont roll back up either, even with the key in the door.

[VStar650CL]

It probably isn't the fob, even a stone-dead fob will start the car if you put the key in the doghouse. The doghouse system is passive RFID, it requires power in the car but none in the fob. The most likely culprit is your BCM. It's remotely possible that it lost programming, but it could also be a no-power issue. They all have a big fusible link (50A+) that provides main power to the BCM, if that's blown then nothing you do will wake up the car. I'd suggest a code-read with a high-end scanner, the BCM and IPDM should both show up even with the key off. If the BCM is MIA, look for a power problem.

[Blessed]

Thanks for the info. I'll look into that and try to get a code read

[Blessed]

Just a follow up to this issue. After taking my Infiniti to 2 different shops and having several different people look at it over the past 3 months, the car is finally running again. Several things were replaced from fuses, to reprogramming the fob, to the BCM, but it ended up being the Intelligent key module/ control unit.
It starts and runs but now I have 2 codes P0037 - 02 sensor, and P0301 - cylinder 1 misfire. At least these shouldn't be too difficult for me to fix myself. Not sure how they could go bad while the car has just been sitting for 3 months though.