Long beep after making left turn

I noticed twice on the commute this morning that my vehicle made a long beep sound after completing a left turn. There were no other warning lights/messages on the dash. The first time, I thought it was something coming through over the radio, so I turned it off, and the sound continued, probably for a total of 6-7 seconds at least. It's similar to the beep that comes on if you start moving and the passenger is not wearing his/her seatbelt. The radio was totally off the rest of the way and it happened at the next left turn I made (when I got off the highway). Although it was icy this morning, it was not particularly slippery at the intersections when I made the turn and I did not notice the TCS coming on, etc. Any ideas?

 

There were no door ajar warning lights coming on so didn't think about that, good point. That being said, the doors were definitely iced up this morning (had to really pull at them to open) so I wonder if there is something wonky with a sensor or something. When I used the key fob to lock the doors, I didn't encounter any issues (i.e. where the warning chime would come on if a door is ajar). I will take a good look at the latches and seals to see if perhaps there is some ice getting in the way or something.

 

Oh, I'm pretty sure there should be a light for that, unless you are referring to the fact that which door is ajar is not specified like it is in many other cars (especially those in the same price range). That and the fact that there is no low windshield washer fluid warning light (yet my old Corolla had it, lol) are two things that surprised me about the car, otherwise no major gripes.

 

Just to update this thread, it was the same issue Lexcyn mentioned, except it was with the rear passenger side door. The warning light was not on, and when I locked the vehicle I didn't notice it (the warning beep did not come on when I locked the doors either). It was only when I returned to the car at the end of the day that I noticed the door was slightly ajar. The doors/door seals were quite frozen that morning, so so it's possible some ice, etc. may have caused the door sensor not to trip.