Good morning all! Newbie here and first time poster so please bare with me. I've been reading through a lot of threads on this issue and I even posted in one of them about this issue with no avail. It was suggested that I start my own thread about my issues to maybe get a faster response so here goes! So I just bought a 2003 silverado 1500 for my son. It has a 5.3 with 160k miles on it. The transmission is original and has never been rebuilt to my knowledge. The motor and transmission are all stock. It only wants to shift at higher rpms. It won't shift any sooner if I let off the accelerator. It shifts hard from 1-2. From 2-3 it had a weird long drawn out shift with a hesitation right before it would shift to third. Everything else was normal. Freeway speeds are fine, lock up is good, reverse is good. So I was gonna check the TPS, as many of the posts I read pointed in this direction, but it's not the three wire plug that is bolted to the drivers side of the throttle body that I can find tons of info and videos on for checking with a meter. Oh no, this TPS is riveted to the throttle body and located on the passenger side along with several wires in its harness! So I pulled the throttle body off and thoroughly cleaned it along with the MAF sensor. I drove it afterwards and my 1-2 is the same but now 2-3 is real sluggish and will slip if you play with the accelerator trying to make it shift sooner. Some of the symptoms lead me in the direction of the TPS but others don't. Does anyone know which wires I need to meter in my TPS harness to check for proper operation or have any other ideas before I pull this transmission and have it rebuilt?!!! Thanks in advance for the help!

Thanks for the reply. I do have access to a scanner. I will have to wait for my buddy to get back into town for any pcm or sensor info. As for the trans fluid, it is on the full mark and doesn't look or smell burnt.