BMW Repair: 2000 323i 100,000+ wont start, filter air, fuel filter

Question
I trailered this car from FL to WI in Dec.  It ran when I left FL but when I got to Wi it wouldn't start.  It turns over but will not start.  It sat through the winter so this spring the battery was dead.  I replaced the battery, fuel filter, air filter.  I am wondering if it has something to do with the key?  I cannot lock or unlock the doors with the key. I can hear the fuel pump running when the ignition is turned on.  I checked for codes but the only codes that came up were for the battery (old code) and one for the thermostat.  Thanks for your help.

Answer
I'll start by assuming the coolant was sufficient for WI winters, and you didn't freeze the engine.

I'm also assuming the locking/unlocking is your key battery.  If it's the key itself not working, there may be a mismatch somewhere.

Does it fire at all when you crank it?  If so, it would mean you are getting fuel, air, and spark to the cylinders.

My suspicion would be that the fuel you have in the car is bad....not "winter grade" additives, and a lot of moisture built up over the winter.  A new fuel filter probably wasn't enough to overcome it.