Thread: PCM not telling car to shift till later

My gears are all working, but for some reason once the car has been driven for a little, then it will wait until higher rpms before the car will shift. Most of the time i will be sitting at 3k rpm in 3rd gear going 60mph. I had a transmission shop look at it and he rode in it with his computer. He was not sure and told me to take it to the dealer. If anyone has any ideas of why this could be that would be awesome. Also, at this point there are no codes being thrown, and I am back on my stock pcm.

When you reprogrammed the PCM, did you do a full rewrite? Is it only holding 3rd gear too long or all the gears?

Did you play with speed and rpm shifting tables? If so.. put the speed table to 0 and adjust the RPM to where you want the shift to occur. (I think that's what I've seen done).

Otherwise you run the need to meet one/both criteria and that's what is likely giving you a hassle.

vac leaks can mess with throttle posistion sensor and cause late trans shifts. especially rubber T on intake under snout.