Can a TPS cause you tranny to shift hard? the other day when I started my truck up in the morning, the engine kind of revved up a little more than usual and went back to normal idle and not long afterward the check engine light came on, and then the transmission started hitting hard from first to second and even a little harder in the other gears but not near as bad.

I talk to a "supposedly" mechanic buddy that works at a Dodge dealer he said there may not be a thing wrong with the transmission it could be something as simple as the TPS so could this be true just wondering? I took the negative cable off for about 10 minutes put it back on and the check engine light went out and it's shifting normal now but for how long only time will tell, just looking for a little feedback.
Thanks!
Mr. Bill

The code will most likely come back and you should find out what the code is. It will help you diagnose the issue.

The TPS is used for shifting but it will not cause a hard shift into 2nd. Some codes cause the tranny to go into limp mode and the line pressure is increased causing a hard shift into 2nd.

My money is on P1870 (do a search on this code).

//2000CAYukon