Well on my 00 GP when I drive it cold it doesn't seem to shift to 4th or OD, I can be going 45-50 and it won't, if i let off the gas the rpms go down like its in OD, but i get on the gas even just very slightly it back in 3rd again. Its very smooth, and when it warms up a little bit will stop doing this. Feels very unnatural to me. Also when warmed up completely if I get on it a bit and it shifts gears in the 3.5 to 4.5k area it shift rough and kinda hard, noticeably for sure. Did on a 1st to 2nd and 2nd to 3rd in that rpm range, so its not just one gear that does it. Doesn't seem to happen really when it ain't up to Operating temp. Only have 48k miles and good fluid level and color. Only other issue with this car is the idle sometimes bounces a bit, and is high when cold, which I would doubt is related.
