Unlocking the Theft Deterrent Feature After A Lockup

In order to unlock the theft deterrent feature, proceed as follows.
IMPORTANT
Do not allow more than 15 seconds to pass between steps. In order to enter your code, proceed as follows.
1. LOC appears when the ignition is on.
2. Press MN and 000 will appear on the display
3. Press MN again to make the last two digits agree with the code.
4. Press HR to make the first 1 or 2 digits agree with your code.
5. Press AM - FM after you have confirmed that the code matches the secret code. The display will show SEC indicating the radio is now operable and secure. If the incorrect code is entered eight times, INOP will display. In order to reenter the code, you must wait one hour with the ignition on. When you try again, you will have three chances to enter the code before INOP display.

If the security is activated and the radio is disconnected from battery power, the radio will display "LOC". The radio will not turn on until the correct unlocking code is entered. If the customer code is lost or unavailable, contact your local GM dealership or an authorized Delco radio service center for additional assistance.