I drive a 2001 Civic and a few weeks ago while I was slowing down to stop at a light, the D light for the transmission started flashing and my check engine light came on. I immediately pulled over and restarted the car, and it drove normally, but the check engine came on which was

code: p0758
1. open or short circuit condition
2. poor electrical connection
3. failed shift control solenoid
It gets stuck in 4th gear

Took my car to a Honda dealership and they reset the check engine light and drove the car for over an hour before they had any problems again. They didn't know what the problem was so they recommended replacing the whole transmission.
My normal mechanic did some research and found a post from another Honda dealership saying in all caps that this code is NOT mechanical, but it is electrical. My mechanic tried a new solenoid, and checked the wiring, tried something with the undercarriage wiring or something. NOT WORKING. He is going to try to reprogram the computer, but other than that, looks like I may need a new transmission.

has ANYONE had or heard of this problem, or have any other ideas as to what it could be? I'm in college and can't afford 3k right now. Thanks