Interesting on the Firebird!!

You are in the ecm's farther than I understand. I believe the 7747's had lean cruise. I don't think it was hacked later. Not for sure.

Glad you are making progress.

Your firebird sounds interesting. What diesel engine?

I also had some difficulty with the TCC controls. Between the conflicting theories of operation around and...

I have not yet attempted highway lean cruise. I just looked and I also have what looks like bad AFR values in the table and max MAP is 37.29. I am using $42-1227747-V5.9.3.xdf. Something may be...

Try looking at the parameter- Hiway-Min Coolant under Highway Lean Cruise. When that gets changed there will be a few negative things happen. Two in particular is no TCC lockup. The other it will...