I just installed an OEM nav unit pat #25857364 into my 2008 LT3 Z71 Tahoe. The install went well, connected the VSS and Voice recognition, when I turned on the radio I got the Theft lock screen. No problem, took it to the dealer to have the VIN cleared and had them program my radio. When I am driving back from the dealership I notice that the chimes and warning sounds no longer work (the worked fine before, even when the Theft Lock screen was up). In addition, the NAV screens default is the HYBRID screen (complete with battery and engine info) I have a Z71! So in short, is this a problem with the TECH II programing or did I buy a NAV unit specific for the HYBRID. BTW when I first started the NAV screen, before it displayed Theft Lock, the GM screen would come on for about 2 seconds, on that screen it used to display "powered by Bose", now it is blank. Thanks in advance for any help you could offer.

 

Sounds like a programming issue

 

I read on another Tahoe forum that somebody else had the exact same issue with this part # (the post was from today and it not had not been resolved yet). Is there a specific NAV that only works for the HYBRID model? Also, is there something in the HU telling the TECH II to program the HYBRID specific info and if so, can this be over ridden? Thanks.

 

These are the reasons the vehicle needs to built with the tech 2 and programed via TIS 2 Web. The radio unlock does work using the 06 monte carlo method but you do not get any of the correct setting for the specific vehicle.
You could also have a radio built specifically for the hybrid tahoe. Have the dealer pull the radio part number with the tech 2 and check with their parts dept.
If the numbers match for all tahoes (same nav radio). Then have your dealer prgram it correctly, via TIS 2 WEB.