Ok, so here goes...when I'm driving my truck, the transmission will shift very eratically, sometimes it won't go from second to third in either od or out of od. At highway speeds it will drive fine for a second then out of nowhere, it will downshift and come out of lockup. Other times the tc wont lockup at all. My transmission was rebuilt and upgraded with billet parts, and a new tc about six months ago by aamco. When it started screwing up, I took it back to aamco, and they said the tranny was fine, but that i needed to have my computer reflashed. Does this sound right? Also, when im going my tach jumps all over the place and doesn't read anything close to what the engine is running at. Any suggestions?

 

TPS or crank sensor

 

ok, I know where the tps is located, but where is the crank position sensor?

 

hi
sounds like the tps !