GRN-BNDT

1994 Del Sol Si Automatic. Whenever I start my car from park, it'll be stuck in second. Usually, when I start to drive, it makes this scrape noise and runs normally and when it does shift, it shifts really cleanly. But, sometimes it doesn't do that, it just is stuck in second and makes this high pitched noise as I drive. Most of the time when it's stuck, if I come to a complete stop and start going again, it'll make the scrape noise and start to shift, but other times it doesn't and I have to drive the entire way running 5k-6k rpms. The tranny isn't low on fluid, I check it regularly, but I'm pretty sure it isn't the tranny since it shifts clean when it does shift. I've been searching around and somebody said something about it being the sift solenoid. That seems like it could be it, but I can't find any information about it. Can anyone help me out please? I'll also add that it's usually harder to get it to make the scrape noise and start shifting when I have to back out of a parking space or just reverse in general.

GRN-BNDT

*Situation Update* I tested the upper shift control lock up solenoid and it checked out. Is there another solenoid to test? Or is it something to do with the TCU?