Is there anyway that a PCM failure i mean electronic failure `could make the tranny to slip?
My tranny was working excelent for 2 or three months since last repair, and last week when i took it to emissions test, i went back to my house driving in a highway 140 kms7 hr, everithing perfect, when went out the highwayt the tranny start slipering again and sent a code the eternal p1870 code, i turn of the car an start it again, and it worked fine.

I doubt the PCM itself could be causing the problem. I've only ever seen them completely good or completely bad.
But it could always be wiring. I can't explain why it would work when you started it again, unless you let it cool down (temperature often effects tranny behavior).

Why my tranny could be getting hotter than usual??

man... you have neverending problems... my tranny is on the way out too, so i feel your pain. sorry to hear it's acting up again

Thanks man, i don't know what to do, it's a new tranny with a new torque converter and it failed again, that's why i think could be another thing.

I hate to say this again, but the curse of the red GP continues....sorry Alex...

maybe check all of your connections to the PCM?

or replace it. i have never heard of this problem, but if it works, then you could save yourself a lot of money.

And its a perfect excuse to mod!

There was a guy in our local club who had a stock PCM, he lost third gear, bought a DHP and it fixed it

So you never know. Might be worth a try

My mechanc told me that maybe he will get my PCM to a friend who works in a GM dealer to reprogram it, we really don't know what could be this now.
My tranny isn't really new, is just one according to my mech, with very, very, very, low miles.

my tranny does the same thing I think the code is P0741,742 it slips and torque converter clutch stuck on or off.When I turn it on any time of the day I have to give it 10-15 seconds before the car will catch the gears but,if I turn it on and put it on drive it sounds as if the motor is being forced and it barely moves

Mine works perfect unless i drive it on highways, it works fine until I got out the highway, then it starts slipering and since i live in a hilly area on uproads it fails and i have to step deep on the gas to get the last hill to my house.
If i drive o¡in traffic there's no problem even on the hills.

What speed are you usually going on the hilly highways?

In a straight road near here there are not too much traffic sometimes 100 km/hr, no failure, but when i go that way i haven't drive from the highway. After the highway there is a road full of curves i don't pass 50 kms/hr and my car doesn't fail there, after that curves I got into this place I live and i have to go slow cause there are kids playing, then a hard hill starts just before arrive my house about 300 mts long and there is when it starts to suffer to climb even there was no gearing, i step on the gas and nothing it was as a charged donkey...

If you put it in a lower gear, is there full power back?

No, that day i tried gearing into 1st and it was the same.

HAve you heard about this?

http://www.techvelocity.com/gtp/trans.htm

some guy reccomend first to check the vaccum line, then the vaccum modulator, and then this kit