KAS

i have a 96 imp, basic mods, f body maf, air intake, brian herter modded computer and x pipe exhaust.
My Problem; transmission went, all metal through it, (yeah i pound on it) Well,(shortened story) I had a trany built by Performabuilt, when 1st unit was installed, by transmission shop, 35yrs in biz, there was no 3rd gear.
Performabuilt sent another unit, said this one they tested in a car. And they installed this one, YEP no 3rd again!
I have my stock computer, i tried that, in case, no difference.
so i'm at a loss, so is the trany shop, they even installed new speed sensor just in case.
the trany shop sent it to a local shop with computer diagnostics, they scaned it, with no codes, no problems noted, all selinoids were told to open, they suggest, bad trany.
My original trany had no problems shifting.
Question? is there any electrical thing that would cause this?
Mr. S

performabuilt2

disconnect the connector on the transmission this will put the trans in limp mode it will default to third gear if it has third this way then you have an electric issue

performabuilt2

Kas, I am a GM tech is it possible for you to send me the data stream from this transmission when it is commanding third gear so i can analyze it.

KAS

I will ask, the 2nd shop might have that capability,

disconnect the main wire harness?

performabuilt

iTrader: (25)

Yes disconnect the harness this should force third you will need to compare Rpm both ways and see if it happens if it does then the trans is capable of making the shift , Though personally I am sure it can since I tested yours personally it made every gear without incident in our test mule van,

KAS

ok, will have them do that in the morning.
now, if its electrical, what would it be?
harness?
is a 1994 buick RM harness the same?

performabuilt2

yes unplug the transmission it will make it go into third if it does go into third then there is an electrical problem if it starts in first then we have a problem

performabuilt2

kas, if it goes into third with it unplugged i would have them inspect the harness coming down from the pcm to the tranny for any bad wires, pinched wires, bare wires

performabuilt

iTrader: (25)

Depends on the year on the harness 94 one type 95 early to to late different and 96 again different.