My auto transmission shifts to low gear and slows the vehicle down with out me wanting it to go slower. This happens after I have made a full stop and then begin to accelerate and then slow down a bit to pull into a driveway. This has happened several times. It happened this morning again. It was very cold today [-2 degrees F]. I believe this has happened even in warmer weather. It seems to happen before the car gets up to operating temperature. I am in Drive not Sport mode when it happens.

Has anyone else experienced this problem? Is it time to go to the dealer?

Thanks for any help on this.