:runaround: I purchased a 2007 factory 6 cd changer in dash Head unit
I installed in a 2003 GMC sierra 2500, replacing the single cd unit.
Turn key to on, Radio shows Locked. Expected this. Went to dealership to get unlocked. From what ive read, 2002 to 2007 is vin locked. They have to hook up the tech2 and tell the radio to relearn vin. When the service guy hooked it up, nowhere in any menu is there a relearn vin option. Any suggestions? Too new a radio for my truck? Really really upset now, guy gaurenteed it would work and now i can't get a hold of him.

I seem to recall that if they are not removed correctly, they get locked and you have to find a hacker to get it to work. I think you need the VIN of the vehicle it came from.

Maybe he sold you a hot radio! The lock is a safety feature to make stolen radios useless.

If your 2007 radio is from a "classic" body style pickup, it will work. You don't need to find a hacker, you just need to find a dealership that knows what they're doing. You do need the tech 2 to unlock it, but it has to be done through GM's service programming. The tech 2 alone can't unlock your radio.

Not much help for you but for your fyi found this on GM website...but the link does seem to work....but the Google cache:

There are currently two different versions of the TheftLock® system that have been used in General Motors vehicles.

VERSION ONE

The first and earlier version works by using a security code made up of four numerical digits to disable all radio functions whenever battery power is removed, such as when the radio is unplugged. On this system, the TheftLock® feature for the radio may be used or ignored. If ignored, the system plays normally and the radio is not protected by the feature. You can activate TheftLock® by inputting your security code. The radio will not operate if stolen. With the ignition off, the TheftLock® LED indicator will flash, indicating a secured radio. The red LED is located on the face of the radio. When TheftLock® is activated, the radio will display LOC to indicate a locked condition any time battery power is removed. If the battery loses power for any reason, you must unlock the radio with the security code before it will operate.

If you are the second owner of the vehicle, you may be unaware of the TheftLock® feature, never the less that there is a code. Many owners and/or dealers write the code on the first or last page of the owner's manual. If you have the code, you can follow the direction in the radio area of the owner's manual to input the code and unlock the TheftLock®. If not, you will need to visit the dealer to obtain the factory code from Delphi Delco Electronics. At this time, the customer may elect to disable the TheftLock® feature so that they do not have the condition reoccur. Most dealers will charge for this service.

VERSION TWO

The second and newer version of TheftLock® is also designed to discourage theft of the radio. The feature works automatically by learning a portion of the Vehicle Identification Number (VIN). Therefore, you don't need a security code to activate the system. If the radio is moved to a different vehicle, it will not operate, and LOC or LOCKED will be displayed. If LOC or LOCKED is displayed, the TheftLock® system has locked up. You must return to the dealer for service. The only way to unlock the radio is by using a scan tool. Most dealers will charge for this service.

www.gm.com/gmcomjsp/contactus/ContactUs_Faq_AnswerVC2.html - 20k -