I have an 02GT with what seems to be the same problem. It is fine most of the time.. but every couple weeks when i'm drivin in hot weather for at least 10-15 miles it will begin to shift hard in 1st to 2nd then 2nd to 3rd. Now, I never had this problem before I had the Transmission Fluid Flushed and Filter changed 2 months ago. However, I left the shop that day with my fluid only half way filled and noticed on my way home the same type of hard shifting. I took it back furious and they topped it off. Car was fine for about a week, then it started the hard shifting again.. Took it back furious still.. did a pressure test and reflush added conditioner everything seemed fine. about 2 weeks later BAM hard shifting again on a long trip I took on a hot day So I think now my problem could be this Pressure Control Solenoid. My question is Could this problem have been caused by underfilling the tranny fluid by the shop, or was it just a coincidence??? SHould i go after them for the Money to fix it? is it not their fault?