93 accord ex flashing D4

I live in Minnesota and this past year when the temperture dropped below 30 and my car was left outside for 8 hours or so I would get a flashing d4 light. I could drive the car with no problems. I could get the indicator to stop flashing by restarting the car. During the night no matter how cold it got as long as it was in the garage I wouldn't get the flashing problem. Kinda of strange. Any Idea's?