I disconnected the TPS with the engine running and tightened the TPS connection and came up with some transmission problems.
It would shift very hard form 1st to 2nd and made some loud noise and was
about 1quart low.
Then after turning the engine off and restarting the problems went away.
So later with the engine off I tightening all the TPS connections(2) by moving the tangs a very small amount using a small flat head screw driver and spraying the connection with w40. Now the transmission shift a little better.
Having never worked on a electronic auto. transmission before. It looks to me if the PCU dose not get a good signal from the TPS you will have automatic
transmission problems.

 

its usually not a good idea to unhook sensors while the car is running

 

the computer uses the tps for shift timing. it will adjust to a different base setting but it takes run time to do so. you should test the tps to make sure its working correctly, they do wear out.

 

Disconnecting the TPS with the engine running can place the TCM and the ECU both into limp home mode. Even if the sensor is plugged back in the car will be in limp mode until the ECU is reset (next start up) When the car is in limp home mode it takes limited readings from its sensors and uses a preset A/F and shift program to get you home. The presets are not ideal but it will allow the car to be driven. Be careful with driving too long in that mode it can cause damage to the tranny, O2 sensors and cats.

Massey