Start with Lock Ease (liquid graphite) found at Wal Mart and similar stores. Follow the directions on the bottle.
The lock would likely also benefit from a good cleaning. It is a pretty easy DIY job. The dealer should be willing to do it, too.
wrote
Any way to fix a car door lock that gets frozen easily?
> My 97 Accord
> has had problems with the driver side door lock the last 2
> winters.
> Last year, there were days when I had to turn the key
> several times to
> get the door to unlock. This year seems to be worse.
> This morning,
> the door wouldn't unlock at all. Had to unlock the
> passenger side and
> then I could unlock the driver side from the inside.
>
> Last time I went to the dealer for maintenance, I
> mentioned the
> problem to them, but they didn't see anything wrong. They
> lubed the
> locks though, but that obviously isn't the solution.
> Something must
> be wrong, as the car went thru its first 10 winters
> without ever
> having this problem.