Definitely water related, you can see salts on the connector and water stains on the module housing. Was there any water down in there? When I painted my tail lights I covered the outside with plastic and taped everything off, water still got in when it rained at 3am and fried my module.
You can order another one with the same part number and serial number and it should be plug and play for the comfort access, mine was when I replaced it but the passenger side doesn't work and I think it's broken also maybe another sensor isn't working as I can close my keys in the trunk and it won't auto open like it used to
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Check and make sure there isn't any water down there, my styrofoam module holder was literally floating down there in an inch of water but I threw a lot of towels and got some desiccant tubs from Walmart and put them back there until it dried out completely.
Check your tail lights, maybe they weren't installed correctly or maybe the rubber around them has plasticized and isn't routing water around the lights properly (I think) which is causing water to get in where it shouldn't.
Just my two cents