I have an 2002 Trans Am, with a 4L80E swap. It was just recently rebuilt and a new converter was put in it. New solenoids, new internal harness.
So here's the problem:
It will NOT shift on its own 90% of the time. I have to command it in HP Tuners and it shifts great then. I've got all kinds of transmission codes. Anyone ran across this? Tuning issue, transmission issue, harness issue?
I'm at a loss here.
Thanks.