Where is the TCM located on the 8L90 trucks? Is it in the tranny or external?
Can I swap a 2015 GMC 8L90 TCM with a 2016 GMC 8L90 TCM to try out the 2016 8L90 OS on the 2015? Will it plug right in and run or will there be VIN mismatch issues?
Another option - Can I update 2015 TCM to 2016 OS? Do I just need to buy credits for both 2015 and 2016 vehicles? Any VIN issues or anything that would not make the 2016 TCM OS run properly on the 2015 TCM?
On the trucks the manual shift mode simply limits the max gear to the selected gear (i.e. if you select M6, it will shift around as it pleases in gears 1-6 but not 7-8). Is there a way to program the software on the truck to basically lock the selected gear so the truck doesn't shift until you push the "+" or "-" button?
One article I read on the 8L90 calls this Driver Shift Control - "Driver Shift Control allows the driver to shift the transmission like a clutchless manual gearbox. Electronic safeguards prevent over-revving if the wrong gear position is selected." (http://gmauthority.com/blog/gm/gm-transmissions/m5u/)
Thanks in advance