I'm swapping a 2015 Camaro drivetrain into a 86 Monte Carlo ss, I had the ecm and tcm tuned by the company that built the harness. My 6l80e wont shift out of first until 3k rpm then goes to third right away and as soon as it's in 3rd it goes back to first. I data logged it and sent to company.. they said it's not communicating and needs operating system to match ecm. They put there generic tune on my 2015 ecm from a 2011 Camaro vin number and said they don't change tcm os due to risk of bricking and I would have to get a local tuner to install a 2013 Camaro ss operating system
guess I got took on that.
I haven't done any tuning on my own, just used hp tuners to download tune on my l5p duramax but willing to give this a go if someone can tell me where to get operating system and maybe instructions and how to tune after that