01 accent will not shift into overdrive

2001 accent had the transmission changed about 6 months ago. For about a month now the car will not shift into overdrive plus you cant get any response from the overdrive button. I have noticed that if the weather is around 30 degrees like today the car works perfect. Any ideas?????? thanks

I am having the same problem with my 01 accent not going into overdrive or the o/d switch on the gear selector not working.

have there been any resolution?

the dealership is not any help as they say they can't fix something that is working correctly. i drove 5-10 miles today on the highway going towards the dealership to show them that the overdrive was not working and 2 miles from the dealership the overdrive kicked in. i just got my car back yesterday from the dealership for other work done (the main reason was for the overdrive but it worked "perfectly" for them)

any help from anybody would be greatly appreciated. sounds like this may be a common problem that the dealerships should know about??