My car is in my garage and engine is off. I closed the door and it beeped once. I opened and closed the back door and the car beeped once.

Today when I closed the door street parking it beeped several times. I don’t know why - I have it set to lock with walk away if that has anything to do with it. This multiple beep also happened in my garage after parking.

 

Single beep is the auto lock engaging. Multiple beeps is when you get out of the car but the key is still inside. That's what my TLX does.

 

It will also do the multiple beep if you walk away to fast “while shutting the door”. The multiple beeps is the car telling you the auto lock didn’t lock the car because you walked away to fast before letting the door fully shut.

 

You're right! I forgot it does that to me occasionally, too.