Chevrolet 1997 Monte Carlo Owner's Manual page 135

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 and this time the display will show
SEC to let you know that your radio is secure. The
indicator by the volume control will begin flashing
when the ignition is turned off.
Unlocking the Theft-Deterrent Feature After a
Power Loss
Enter your secret code as follows; pause no more than
15 seconds between steps:
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 your code.
4. Press HR 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.
The display will show SEC, 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 chances to
enter the correct code before INOP appears.
If you lose or forget your code, contact your dealer.
Disabling the Theft-Deterrent Feature
Enter your secret code as follows; pause no more than
'i
15 seconds between steps:
1. Turn the ignition to ACCESSORY or RUN.
2. Turn the radio off.
3. Press the 1 and 4 buttons together. Hold them down
until SEC shows on the display.
4. Press MN and 000 will appear on the display.
5. Press MN again to make the last two digits agree
6. Press HR to make the first one or two digits agree
with your code.
with your code.
7. Press AM-FM after you have confirmed that the
code matches the secret code you have written down.
The display will show ---, indicating that the radio is
no longer secured.