Here's the tune file I have for a 2011 GMC.... It's the closest one I can find, I literally have none that match the speedometer segment for his vin. The original speedometer segment # was 12646357. What are your thoughts? Should they be compatible?
Boot Software 12646251
Slave Operating System 12646250
Main Operating System 12646249
Engine 12655862
Speedometer 12646359
System 12655886
Fuel System 12646324
Engine Diagnostic 12655870
Engine Operation 12655864
Thanks!