Initial flash of T42

[frodo84]

Replacing the transmission controller on a 2008 Silverado, I uploaded the calibration from my old one and tried to flash the new one but got an error saying the OS was different. Do I have to find a newer calibration to match the new module? I've been looking around but haven't found anything. Thanks for any help or advice.

EDIT: I think I need a T42 stock tune (2008 Silverado) that uses OS 24252617. If anyone can point me in the direction of one I would appreciate it, thanks.

[Autovation]

I've tried it many times with no luck. The OS is pre programmed into the controller. GM MDI and TDS web is the only way to do it on your own. I trailer them to a dealer when I rebuild transmissions and /or replace the TCM.
I think I've still got a flat spot on my forehead from beating my head on the wall trying this one over and over.

[frodo84]

Thanks for the reply. I had to get a controller from a third party, programmed to my VIN.