Blazincopper

I have a Pontiac G8 setup with a 6l80 in a 67 Camaro. Psi harness. Got the car on the road and it will not shift out of first. I hooked my scanner up and the commanded gear is always 1. I am getting a rpm speed signal. I noticed the gear ratio is 8:00-1. I don't know if that is what it should be or not. I have not had any tuning done to the trans yet. I used my scanner to command the solenoids and they all changed state on the data stream. The brake switch is always showing applied even when the pedal is not pushed . I am getting voltage from the coverter lock up wires when they are not connected to the brake - 8v from one wire and 7 from the other wire - can't figure that one out.
Any suggestions. Thanks in advance

joecar

Are the upshift/downshift tables populated for all shift patterns...?

What software are you tuning with...?

joecar

Are you getting VSS signal...?

joecar

What engine/ECM...?

Blazincopper

It's the factory G8 58x ecm. I just had the vats removed so I could get it to crank. I don't have any tuning software. Im reading everything from a diagnostic scanner.

joecar

With your Genisys are you able to read VSS (vehicle speed sensor, MPH) from the TCM...?

joecar

Or can you read a valid OSS (non-zero)...?

Blazincopper

Doesn't look it. At least not from the tcm. All the speed readings are in rpm

joecar

I've heard from various of my sources that your harness may have a few problems, you should check the harness out before proceeding.

joecar

I mean: unravel the harness and check its wiring, connectors, crimps, and ohm it from end-to-end using a good DMM.

Blazincopper

So there have been some issues with the PSI harnesses for the 6L80? I'll check everything out tomorrow and let you know - thanks for the help

lownoma1993

I know this is a old thread, but I'm having the same issue, did you figure out the problem ?

TXjeepTJ

iTrader: (8)

I'm having same issue, wish people would check back in and let everyone know the solution!

lownoma1993

Yes, I've actually had to deal with this a few times now, basically I've ended up with engines and transmissions ( 6l90's ) that were not out of the same ( original ) vehicles or with different os' (
​​​operating system) so the ECU and TCU (the TCU is internal and part of the valve body on 6l90 and 6l80's ) did not have the same VIN's. So long story short I had to find someone that could "marry" the ECU and TCU then had to remove the TCU and ship the ECU out with TCU. When I got them back and everything hooked back up everything worked like it should.