Quote Originally Posted by FordXplod93
I fished around online for awhile and here's what I came up with. All of it is legit except for where you have to fax this guy your number. I would instead take that number to a Chevy dealer. Hope it helps.

In order to properly restore your radio to operation you must first obtain the scrambled back-up code from the radio.
1. Turn ignition on and radio power on.

2. Press and hold presets 2 and 3 for about 6 seconds until the first 3 digits of the display code are displayed. Write the numbers down.

3. Press the AM/FM button, and the second 3 digits of the scrambled code are displayed. Write these numbers down. If the numbers do not change when pressing the AM/FM buttons, then your second three numbers are the same as the first three.

4. Fax me (FAX 1-888-995-9496) your name, your 6 digit code and your naisso member number. I will also need your daytime phone number to call you back to confirm. I will call GM and retreive an unlocking code, which only takes a few minutes. The reason I limit this to members is that I know most of you by name and this will limit the chances of anyone with a stolen radio from contacting me.

Once you receive your four digit unlock code from me do the following:
1. Ignition on, Radio OFF.

2. Press the HR button until the "LOC" disappears and "000" appears on the display.
Note: if the display does not change from "LOC" to "000" the unit is probably in the "InOP" stage and must be left alone for one hour with ignition power applied. Every three unsuccessful entries will put the unit into "InOP".

3. Set the first two digits (01-19) of the code with the HR (hours) button. (you will not see the zero if the first digit is a zero as in "02" for example)

4. Set the next two digits (00-99) of the code with the MIN (minute) button.

5. Press the AM/FM button to enter the code. The radio will now be unlocked and the display will change to the clock. Continue with the following steps to deactivate the theft deterrent.

6. Press the HR button until the display changes to "000".
7. Repeat steps 3-5 above to remove the previous code and deactivate the theft deterrent system. You may set a new personal security code as per your owners manual instructions.