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C6 Stereo Locked


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A Few weeks ago my cd player went Tango Uniform on me. So I jumped on line an purchased a used one. What I didn't know is that GM felt it necessary to make this a difficult swap. Currently the used stereo is giving me the "locked" notice.

Did a quick search and found that you either have to take to the dealership or follow these instructions:

How to Reset GM Theft lock Radio's


The following instructions will allow you to reset any GM (General Motors), Cadillac, Oldsmobile, Buick, Pontiac theft lock radio.


The theft lock radio must be in "LOC" mode.


1. Turn the ignition ON (The radio should display "LOC")

2. Hold down the Radio Presets 2 and 3 buttons for six seconds

3. The radio display changes from LOC to a three-digit number. Write this number down. You now have fifteen seconds to complete the next step.

4. Press the AM/FM button

5. The radio display changes to another three-digit number. Write this number to the right of the first one.

6. You now have a six-digit number, the first three digits are from STEP 03 and the last three digits are form STEP 05

7. Call 1-800-537-5140 FREE

8. Press 1 then # (pound). You'll hear "Invalid Code, try again"

9. Press 139010 or 106010 or 206010 or 202107 then # (pound). You will be asked to enter your four or six digit code followed by *

10. Enter the number from STEP 6 then *

11. Listen to the four-digit number and write it down. It will be repeated twice

12. Turn the ignition ON (The radio displays LOC)

13. Use the MN and HR buttons to enter the code from STEP 11

14. Press the AM/FM button. The radio display changes to "SEC". Your radio is now "un-locked" and usable.

15. Dealership Codes








If you fail to enter the correct code eight times, the radio goes into INOP mode. You have to wait an hour with the ignition on before the radio returns to LOC mode.

I've just finished the install. Does this work?


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That quit working with the 2000 to 2003 model years....

How do I know? I just tried swapping the am/fm radio from a 2007 work truck to a 2005 work truck.

I tried that procedure until my fingers went numb :lol

Then Google showed me why it wouldn't work (model years)

You're not completely out of luck though, there is a way to open it up and snip out the offending security chip...

YouTube is good for something other than Russian car crash videos.


I didn't try this so buyer beware.....


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Thanks Dawg. Wonder if I can just swap the CD reader and put the same unit back in?

Can the dealership still unlock them?


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Yeah I believe I read that they can, or anyone with a tech2 might be able to do it for $50 less.

Probably best to let Ed from Coulter check into it for you first. Shoot him a PM.

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