Well I have been going through all the threads on the forum trying to diagnose a transmission problem and haven't found the answer yet, so I thought I would start my own.
I have a 98 Pathfinder and all of s sudden out of nowhere, my transmission will not shift out of third gear. P, R, N, 1 and 2 all work fine, but when I am going down the road, it cycles through first and second just fine but when it should shift into 3rd, the tach revs up to 4000 RPM and acts like it shifts into nuetral. If you let off the gas the RPM's will drop right down immediately, but it won't go into third gear.
I have a 4 speed Auto w/OD and tried running the tranny with the OD turn off, still no shift. I tried to manually shift from 1 to 2 to 3 (D) and it wil shift fine from 1 to 2, but won't shift manually into third either. I thought maybe the TPS was bad, but I bought a new one and it didn't fix the problem. I read on the forum somewhere that the TPS has to be adjusted but I am not exactly sure how to complete that process. It looks like you can rotate it backwards, but how do you know when you have it in the correct position. Again, that's assuming this has anything to do with TPS. The other thing I noticed mentioned on the forum was potentially a bad A/T Shift Computer. Don't know where it is located to even check, but this doesn't seem like it would be the problem to me since it works in all the other gears.
Anyone think they can help?