Been having issues with my Fit for the past 5 months. It seems whenever it's warm outside the 2nd gear pressure switch acts up. What happens is once I drive it for a little while (10-15 miles) the dreaded flashing D and the check engine light comes on. So far I've had two Honda dealers look at it. The first one changed the pressure switch twice but no luck. The second dealership replaced the ECM per Honda Tech but that didn't help either. I decided then to take it to a transmission shop hoping they could resolve the issue. The only thing they did was break the housing where the 2nd gear pressure switch is mounted to the transmission. Guess what - the transmission was replaced. Even after the transmission was replaced I continue to have the same problems.
Picked it up today. Temp around 90°. Driving home I knew it was going to act up again and sure enough it did. Ran into a sandwich shop and got back in the car. Got onto the road and sure enough - flashing D and the car would shift past 3rd gear. My guess is I have some kind of electrical short and cold be cause when the car is getting hot. By the way - the "hot" coolant light does NOT come on.
Anyone have any ideas what to look for. Losing my patients but no choice but to keep searching.

 

Given the history, I'd have someone look at the components before or after the switch...or the wiring. Don't know why it would only malfunction when hot, however.

 

Have you done an OBD II check? code? or no code? 'past 3rd gear' does that mean from 2nd to 4th ?

 

No updates... Too many sandwiches