Key fob and battery dead...BCM replacement? Help please

2014 CX-9. My key fobs stopped working. Then months later i have dead battery. Could not charge battery with out theft deterent alarm going off. Had it towed. They replaced dead battery Key fobs not working. Ordered outrageously expensive $ 358.00 new fob and still not working. Mechanic says bcm not working.

Mechanic says if i dont want theft deterrent or use key fobs i can take it home without replacing bcm. New bcm $958. Will it damage anything else in my car if i just bring it home without replacing bcm and forget using key fobs? Help please…
 
Yes, you can use the key only and not have any theft deterrent features. I'd have to check when I get home, but I thought there was a theft deterrent module, rather than the BCM doing this task.
 
Confirmed. There is a "keyless control module", #13 in the diagram. Based on what you have told us, I would look at it before the BCM.
 

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week of Xmass 2019, i had similar issue. I was planning to run somewhere and started the vehicle. about 30 sec, car shut off. KEY light was red. i couldnt use the metal key because I have 1 key and keep metal key on the chain of my other car. long story short. i checked fusebox. I forgot the fuse number. it was 10amp calls speedometer. it was blown. i replaced and started ... samething, blown. I went to dealer, they said speedometer needs to replace. $1200 + 7 days progress (mileage transfer...bla bla).

I bought new fuses at napa. removed entire fuses in the glove box and tried to find which feature gives issue and blows the fuse. i install 1 fuse and start the vehicle.shut off another one. when i complete the entire fuses, car worked fine. What was the issue, I was driving night time before a day and speedometer was on night drive mode. i turned day drive mode on then tried the fuses. everything fixed for $10 (2 boxes of fuse).
 
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