u/Extension_Addendum26

Same thing happened when they upgraded Hundai vehicles 2 years ago. Dealer ttold me they only added decales, but paperwork says software upgrades. According to what I can find, it could be caused by the Body Control Module since it controls the security system. During these issues when I had to use my key to unlock the car, the alarm never once went off. Apparently the Body Control Module stays on and it looks like it drains the battery if the car sits a few days without being started or used. Had the car jumped the first time and all worked for a while until the car sat idle for 2 days when I was ill. Had to have the car jumped a second time. Taking it to the dealer tomorrow. Sent information about the issue to Hyundai.