2016 TLX. No previous issues. About a week ago the alarm would randomly go off (5pm, 3am didn’t matter what time just random). Thought it may be the neighborhood cats getting on top of the car but realized it wasn’t. Over the last week it increased in frequency. Yesterday we tried just leaving the doors unlocked for a few hours which fixed the alarm going off, but then a new issue. If it’s unlocked, the headlights and interior lights randomly turn on. After 5-10 minutes they seem to turn themselves off right now. I turned the interior lights off so we don’t drain the battery but can’t turn the headlights off all of the way of course(won’t stay in the off position). So it’s either leave it locked and the alarm goes off all the time, or leave it unlocked and worry about the lights staying on and draining the battery. Worried if I unhook the battery to kind of reset everything I’ll have to go through “relearning” everything that I’ve read about. Tried talking to the dealership who said they won’t be able to see it for weeks and may not be able to diagnose it. Help!!

 

1st to note; "relearning" everything isn't that worrisome... as it might be a bad battery. How old is the battery and what is the voltage of the battery?

2nd to note; it might be a door sensor.

 

New here so sorry if I replied wrong.
we just bought the car a few months ago and I haven’t looked at the date on the battery but I want to say it’s original. How would I go about seeing if it’s a door issue? Right now, no lights come on showing me doors, trunk, hood are open

 

you didn't reply wrong, you are doing great!

1st, I would check the date of the battery and the voltage of the battery. when the car is off, the battery should read 12.2-12.4 volts.

 

I had no idea the battery could cause problems like that! I’ll definitely start with battery and see where that takes me

 

What should I look into doing next when new battery isn’t making a difference?

 

the car is thinking a door, trunk or hood has opened setting off the alarm. Common culprit is the hood latch being faulty but don't just throw parts at it! Check the door sensors on the door jambs and check the hood latch.

 

I would also look at fuses. check all fuses.