GM Radio won't unlock

[greasybob]

Have a 2012 Tahoe here with a navigation radio that needs replacing. I obtained a used radio with matching part numbers and RPO code. I programmed the radio with GM AC delco TDS to get the proper setup. All the calibration numbers changed to match the vehicle but when programming was complete the radio remained locked. I'm not new at this and have done many dozens of GM radio replacements in the past. This the first one that would not unlock. I have no other codes in the vehicle and all communication systems seem to be working. I even tried a couple of internet solutions including open the door after programming and using Tech 2 enter the vehicle as an 06 Monte Carlo and try VIN erase ( B.S. That function is not available for that vehicle in tech 2). Any Ideas ? The programming process runs as it should, no warnings or other messages.

[greasybob]

I just checked the VIN that is stored in the radio with the tech 2 (SnapOn software does not list VIN data for this module in this vehicle) and it does not match the VIN for the vehicle. The VIN stored in the BCM is correct for the vehicle. So the reprogramming is not rewriting the VIN into the radio, first time that I can recall running into this problem .

[Glide]

You'll have to flash it with SPS.Any GM truck radio has been that way since 99 new style.

[greasybob]

That is what I have been doing. The calibration numbers change but the VIN is not re-writing during the flash for some reason. I noticed some substitution errors in the Theft Deterrent Module when checking last night, so I will try to correct those first. Did you know that Tech 2 Win will give you 30 instead of 3 just like GDS ?

[Glide]

Originally Posted by greasybob

Did you know that Tech 2 Win will give you 30 instead of 3 just like GDS ?

No I didn't.I have only used Tech2Win a couple of times as I have a Tech2.What interface are you using to flash? Do you have access to a MDI?

[greasybob]

I'm Using Pass Thru Pro 3. This is the 2nd radio that I've tried with this vehicle with the same result, so probably not the radio. No MDI available. I"ve done this many times in the past without problems maybe GM changes something recently, they're not to big on supporting used modules.

[Glide]

Originally Posted by greasybob

GM changes something recently, they're not to big on supporting used modules.

That is always possible.I've replaced newer radios with used,but not Nav.What was the issue with the original radio?

[greasybob]

It would light up but no functions, blank screen, no sound, no communication.

[Glide]

Did you check as per PIT4474E ?

[Speedybon]

It needs to go to the dealer. Programing Radios are very tricky. Programming any late Gm product is hard. And time consuming.