I am new here but I have been searching countless threads trying to figure out what the issue is with my Tahoe but I cannot seem to even find the same situation. What is going on is that my car is saying unknown driver every time I try to drive it. Now normally it seems like this would prevent the car from driving, however that is not the case. While this is going on I can drive just fine its just I cannot mess with any of the door controls, all my gauges outside the speedo and tach do not work, the air conditioning does not work, and the rear AC controls will not work. What is also is weird is that for moments before I turn the motor on everything seems to work just fine but it quickly returns to the unknown driver mode and after I turn the motor off but before I remove the key everything seems to return to normal. I have checked all the connections at the ECM and BCM and it all seems fine, I have checked every fuse, and I have tried to disconnect the battery cables. In addition to all of this I have had this issue about a year ago but for some reason it just stopped after a few days. I am at my wits end and would love some further suggestions from anyone that might have an idea of what could be causing this issue.

Thanks again for any suggestions!

 

I had this issue
Disconnect Battery negative. Put key in the ignition but don’t turn on. Connect battery cable.