AT trans shifting from 1st to 2nd at 15mph and to drive at 20 then overdrive at 25 once warm no matter whether at 10% throttle or on the floor. really leaning towards a out of adjustment tps. I have adjusted the throttle cable to toyota specs. that adjustment had no effect on shift points.

 

No one? Am i the only one who has had this problem? i did some testing last night on the tps. It looks like my problem might be there. Replacing it with a known good tps tonight and i will keep everyone updated.

 

replaced the TPS yesterday evening and all is good in my world now. Truck shifts at varying rpms depending on throttle input and will know also downshift when needed.

 

I was going to say check the transmission computer for throttle position signals, but you already figured it out