Unlock radio after replacing instrument cluster

Gm Delco theft-lock radio unlock code:

1. Press and hold presets two and three for about five to ten seconds until you
get three digits on your display. This is the first three of six digits you will
need, so write them down.

2. After doing step one and writing down the code, immediately press
the AM/FM button to get the last three of the six numbers you will need, and write
them down. (If you wait too long between steps one and two and the LOC code
displays again, just start over).

3. Call this number, it is a prerecorded message, so do not worry about
having to talk to anyone. 1-800-537-5140. The voice will ask if
you are calling for Chevrolet, Pontiac, Cadillac, etc. When you here him tell
you to press "2" for Pontiac, press 206010 and hit the # key. He will ask
you for the six digit code that you have written down.

Enter that and press the * key. He will then give you a code, and the option to get additional four digit codes, but one should be sufficient.

4. Follow the normal procedure in your owners manual for unlocking the
radio with your new code. Press the hour set button on your radio
until you get the first two numbers of the code, then press the minute set
button until you have entered the last two numbers. Immediately press
the AM/FM button once the correct code is entered and the code SEC or
"secured" will be displayed on the display screen. Now, just turn the
radio on, and your ready to roll.

There is an additional step you can take to remove all codes from the
radio and start from scratch by entering your own personalized four digit
code so that it will not get you in a pickle again! Just repeat step four
and you should get a display screen that reads ---. This means the code is
out, and you can now program your own code. Of course, once you
receive the four digit code from the GM recorded message, just keep it in a safe
place, because you can use that same code again and again should you
have any more problems with it in the future. Good luck, and yes, it
does work.

If you still have trouble you will need to take it to the dealer so they can burn a new code should cost about $130.00

Go to dealer they have to change code in cluster. Also I found this information ont he problem as well

Locate the Radio’s Serial Number: You'll need the radio's serial number to proceed. This is sometimes printed in the owner's manual or visible on a sticker on the radio itself (which would require removal of the radio unit).

Retrieve Unlock Code: The unlock code is unique to each vehicle or radio. If you don't have this code:

Check the owner's manual or any documentation that came with the vehicle. Sometimes the code or a radio card is included.
If you can't find the code, you'll need to visit a Pontiac dealer or a car audio specialist. They can retrieve the code using the serial number and proof of ownership.
Entering the Unlock Code: Once you have the code, turn on the radio. It should display a message like “LOC” indicating it's locked. Enter the code using the radio preset buttons. For example, if your code is 1234, press preset 1 once, preset 2 twice, preset 3 three times, and preset 4 four times.

Confirming the Code: After entering the code, press the “Enter” or “OK” button on your radio. If the code is correct, the radio should unlock and function normally.

Where did you get cluster?