Ha! I also had the back hatch not locking the other day at about -20C. I was going to put some graphite lubricant on it, I have found that it helps in the past. Unless somebody has a better idea?

 

Sean,Marc - our Russian guys have one issue, it may be helps:Under the rear door(hatch)you can find two rubbersprings about 2cm indiameter. It designed for shock absorbing when driver closing a door. You may try to turn it clockwise, it slightly lowers and door will works fine. If you turn it too much, the door will "clunk", then turn it counter-clockwise. No special tools required.

 

Thanks for the info. In my case I know it is the latch being frozen. I manually closed the latch and it would not catch, later when it was warmer I did the same thing and it would lock so it does seem to be the cold that is affecting the latch mechanism itself.

Sean

 

May be, Sean.

Earlier I thought same.One our guy tried to disassemble the lock - zero effect.
Hint: At low temp rubber stay harder and doesn't let the door works properly.
MMC provided that and has designed thisconstruction- Isaw it never before on my cars.
In one look it's very simply, in other - need to human advice.