Buick 2004 Park Avenue Owner's Manual page 194

1. Write down any three or four-digit number from 000
to 1999 and keep it in a safe place separate from
the vehicle.
2. Turn the ignition on.
3. Turn the radio off.
4. Press the 1 and 4 pushbuttons at the same time.
Hold them down until --- shows on the display.
Next you will use the secret code number which you
have written down.
5. Press MIN and 000 will appear on the display.
6. Press MIN again to make the last two digits agree
with your code.
7. Press HRS to make the first one or two digits agree
with your code.
8. Press AM-FM after you have confirmed that the
code matches the secret code you have written
down. The display will show REP to let you know
that you need to repeat Steps 5 through 7 to confirm
your secret code.
9. Press AM-FM again, SEC will appear on the display
indicating that your radio is secure.
3-76
Unlocking the Theft-Deterrent Feature
After a Power Loss
Enter your secret code as follows; pause no more than
15 seconds between steps:
1. Turn the ignition on. LOC will appear on the
display.
2. Press MIN and 000 will appear on the display.
3. Press MIN again to make the last two digits agree
with your code.
4. Press HRS to make the first one or two digits agree
with your code.
5. Press AM-FM after you have confirmed that the
code matches the secret code you have written
down. SEC will appear on the display, indicating the
radio is now operable and secure.
If you enter the wrong code eight times, INOP will appear
on the display. You will have to wait an hour with the
ignition on before you can try again. When you try again,
you will only have three more chances (eight tries per
chance) to enter the correct code before INOP appears.
If you lose or forget your code, contact your dealer.