Ok since i am new here, i think my truck is considered a 4th gen (2003 toy tac d.c. 3.4L auto) . I was wondering if anyone else with a similar year truck has this problem. I have a button on the dash (ect power) that controls the transmission for fuel mileage or for power driving. When i have the button pressed in for power driving( i press it in for onramps and passing situations) i notice what i think is a trans problem, but ive owned manual trans for so long i just dont know if its supposed to be like that or not. If i punch it from the line, say for gettin of a freeway, i notice that when it shifts from 1st to 2nd it almost seems like there is a stall. Not like a slipping i dont think, it more reminds of like if you missed a shift in a manual, it almost feels like the truck slows down for sec the 2nd engages. Through the rest of the gear range it shifts, from what i remember of automatics lol, just fine.

It does not do this shift problem with the button pressed out , i.e mileage, it does not do the problem seeing that the computer is shifting the truck at a lower rpm for gas mileage.

I have never owned a toy with an automatic so i dont know if im just that far out of the loop or that i might actually have a problem. Its still under warranty so itll be no big issue to fix, its just the time and such of taking it to the dealer. I dont wanna take it to the dealer and look like an idiot when they say theres no problem. Thx for your help guys.

 

my 3rd gen (2000 4R SR5) does not behave in the way you describe with ECT engaged; it shifts smoothly, just at higher RPM

like you, this is my first auto trans in over 15 years so I'm very aware of how it behaves vs. stick (oh God how I miss my stick - but that's been covered ad naseum on other threads)