[BO185]

What TCM do you have if its standlone then just need to add correct TPS and inputs to TCM.

The Max will run the 4l80/85 and engine all in one no external TCM needed.

 

[BO185]

Had A Few
I appreciate all your help, I'm working with a shop that has suggested replacing the X with the X Max (554-153) and associated trans harness ( 558-405 ). here's hoping all this works.
Thanks again.
Russ

The GMPP controller is standalone. pn 19332780 and will work...

You DON't NEED the max just yet. Fix what you have.

The Transmission Control Harness requires connections to
1. The transmission (20 pin),
2. The output speed sensor (OSS)
3. Input Speed Sensor (ISS) on 4L80E
4. The Transmission Control Unit (TCU)
5. The Throttle Position Sensor (TPS) on the carburetor
6. The tach lead on the distributor cap (carbureted engines)
7. Ignition power (12v with key in run position)
8. Battery power (12v at all times)
9. Battery ground (battery negative terminal or solid engine ground).

Are these all hooked up?

Is the TPS sensor hooked up?
And the tach lead???

 

[BO185]

I would have them hook and OBD II code reader to the port in the wiring and see if there are any TCM codes. IF you have a code reader and see where the OBD II port is you can see if there are any codes in it yourself. Should be a code telling as to why its not going in 4th or locking up.