Today I was driving at around 40mph when I went over road imperfections. All of a sudden the driver's door got opened and a warning message lit on the dash. Then I heard the door closer sucking the door back in.

That scared the you know what out of me. Possible explanations? How do I make sure it doesn't happen in the future?

LS460, '08, swb, 50K miles, no other issues.

 

my guess is the door wasn't latched on completely. funny thing is the same thing happened to me once in my gs350. i was driving, all looking good, and suddenly i heard a pop on my driver side door and then tons of road noise and the dash door warning came up.

luckily i came to a traffic light, so i tried to push on the door. it's actually latched on the first lock (the one where you can't just push it open anymore but it's not fully locked on). there was a bit play but that's about it. i opened the door manually and then shut it again, everything was good since. i have never seen that happened again

so i just think it wasn't completely latched on, probably a little glitch. sounds like the same in your case, it's still latched to the first click, that's why the suction closed the door again for you

 

My guess is that the seat belt was caught in the door. I've done it.