Suddenly Slipping tranny

I own a 1994 Camry XLE with the 1MZ 6 cyl with the automatic transmission. The car has approx. 154K miles. While returning home from work tonight, I was stopped and waiting at a red light , when it changed, I pulled away but the engine began to rev higher before the tranny caught on. First time it ever happened! When I got home finally, the car would hardly make it up the shallow incline into my driveway. I checked the fluid level on the dipstick, it looked a little high on the stick while in the park position with engine running. I checked fluid level after turning engine off, again was a little high. Any suggestions as what to troubleshoot? Is there a modulator valve or something similar on this transmission that may need changed?. I had this problem with an older GM car and after changing out the modulator valve, it solved the problem. Any ideas or suggestions would be greatly appreciated before I go spend 2 arms and a leg getting this thing diagnosed.

Regards
Gomer

Interestingly, my 94 Camry is at the Toyota shop right now for something very similar. Transmission stops pulling and you almost have to floor it to get 10-20mph. Check engine goes on and O/D light flashes. Toyota has replaced both the speed sensor and speedometer head, both to no avail. Please post here what you find out to be the problem. I'll do the same.

that is interesting...I have a 1992 Camry and it has over 210000 miles, and it still runs great!!!

after several mistrys by Toyota to remediate (speed sensor, speedo head), they replaced several new wires from the combo meter to the computer which seems to have fixed it. They indicated to me that 95% of erradic shifting is speed sensor or speedometer head related. Good luck.