Hi Chris

I too do not have very much experience when it comes to automatic transmission.

I do know that when most auto's have an electrical problem it will probably default to 3rd gear, meaning it will have a slow take off.

What scan tool are you using to connect to the transmission?

Is there any live data available?

After the vehicle has set off does it change through the gears are stay in just 1 gear?

What engine size is it?

James