Radio locked up

Step 1: Look at your radio. Check and see if the code "RDS" is written on the face of the radio. If "RDS" is present, contact a GM dealership to have your radio unlocked by them.
Step 2: Check for the identification code. Press buttons 2 and 3 for 8-10 seconds. If a code does not appear on the display, you won't be able to unlock your radio in this manner.
[If that doesn't work vvv]
In order to obtain your radio unlock code, you need to find your radio's serial number. You can get the radio serial number directly from your radio.
Step 1: Turn on the ignition. Turn the key to "accessory" mode or "on" mode.
Step 2: Turn on the radio. Press the power button to turn on the radio.
If your radio displays any functions such as playing a CD, cassette, or a radio station, your radio is not locked. If no sound is heard, you may need to replace your radio unit.
If your radio is locked, "LOC" is displayed on the screen.
If "INOP" is displayed, keep your ignition on for 60 minutes with "INOP" on the display. After the hour is up, it should change to "LOC." After this you can proceed with the next step.
Step 3: Write down the code. Press buttons 2 and 3 at the same time and hold for 8-10 seconds. Write down the three-digit code that is displayed.
Step 4: Note down the code. Immediately press the AM/FM button. Another three-digit code is displayed. Write it down as well.
This is your six-digit radio serial number.

Now that you have your radio's serial number, you can obtain the radio unlock code from General Motors. Be ready with a pen and paper to write down your radio unlock code.
Step 1: Contact the GM radio hotline. From any landline or cell phone, call the toll-free GM Radio hotline at 1(800) 537-5140.
Step 2: Enter the code. When it requests a code, enter "106010" on the keypad, followed by the pound (#) sign.
Step 3: Enter the radio serial number. You will be prompted to enter the radio serial number you have just obtained.
At the prompt, enter the number followed by the pound sign.
Step 4: Write down the radio unlock code. The prompt will read out your four-digit radio unlock code. Write it down precisely.

Now that you've obtained your Chevrolet radio unlock code, you need to enter it into your radio.
Step 1: Switch on the radio. Turn your ignition on and press the radio power button. Your radio will display "LOC."
Step 2: Enter the first two digits of the radio unlock code. Press the hour button on the radio to enter the first two numbers of your radio unlock code.
Continue pressing the button repeatedly until the first two digits of the radio unlock code are displayed.
Step 3: Enter the last two digits of the unlock code. Press the minute button until the last two numbers of the radio unlock code are displayed.
Repeatedly press until they match the two digits you need.
Step 4: Confirm the code. When the code matches, press the AM/FM button. "SEC" will display on the radio, indicating a successful attempt to enter your radio code.
If you enter the code incorrectly eight times, the display will switch from "LOC" to "INOP." You'll need to leave the ignition on for an hour as described in Part 2 before you can retry.
Write the radio unlock code in a safe place such as in your owner's manual for future use.
Most car dealers will charge you a lot of money just to get the code for you. If you follow the right steps, you can get the code for free and be able to start listening to the radio again in just a few minutes!
How to Unlock Chevrolet Theftlock Radio

How to Unlock a Chevy Radio Step 1: Start the vehicle and turn on the radio.
Step 2: Press and hold preset numbers 2 and 3 until a three digit code appears on the radio display. Write this code down.
Step 3: Press the AM/FM button. Your radio will display a second three digit code. Write the second code down. You will now have a six digit code.
Step 4: Call the Chevy Radio Code phone line at 1-800-537-5140.
Step 4: Enter 106010 followed by the # key to direct you to the radio code retrieval system.
Step 5: Enter the six digit code you retrieved in steps 2 and 3 followed by the * key. They must be in order. You will be given a four digit radio code. Write down the radio code.
Step 6: Start your vehicle and turn on the radio. Using the Minute and Hour buttons, enter in the four digit radio code to your stereo system. Press the AM/FM button to unlock your stereo.
How to Unlock a GM Radio Step 1: Start the vehicle and turn on the radio. The radio will display "LOC" indicating the Theftlock system is activated.
Step 2: Press and hold preset buttons 1 and 4 for ten seconds. (If you don't have a fourth preset button, press and hold presets 2 and 3.) The radio will display a three digit number. Write this number down.
Step 3: Press the AM/FM button. Your radio will display a second three digit code. Write the second code down. You will now have a six digit code.
Step 4: Contact your local GM Dealer and give them the six digit code. They will give you a four digit radio code.
Many dealers will give you your radio code for free, while others may charge a small fee. If your dealer is charging a larger fee, consider calling another dealer or doing a Google search for sites offering GMC Radio codes. They usually charge a small (around $10) fee.
Step 5: Start your vehicle and turn on the radio. Press the Hour button on the radio until the first two number of the code appear. Next, press the Minute button until the last two numbers of the code are displayed. Once all four digits appear, press the AM/FM button to unlock your stereo. The display will read "SEC" indicating you have successfully unlocked your radio and it is fully operational.
If radio display reads "INOP" while the vehicle is on, too many incorrect radio codes have been entered. To remove "INOP" from your display and unlock your radio, you must leave the key in the On position for one hour. Once you've retrieved your radio unlock code, write it down for future use. Your radio code will not change and having it handy will save from going from the radio code retrieval process again.

oN STERIOS THIS NEW YOUR ONLY CHOICE IS TO TAKE THE RADIO TO THE DEALER AND HAVE THEM SHIP IT IN TO THE FACTORY FOR REPAIR AND WHEN YOU GET IT BACK YOU WILL PROBABLY HAVE TO TAKE IT TO THE DEALER TO HAVE IT PROGRAMMED

Try this: How to Unlock a Chevy Radio Step 1: Start the vehicle and turn on the radio.
Step 2: Press and hold preset numbers 2 and 3 until a three digit code appears on the radio display. Write this code down.
Step 3: Press the AM/FM button. Your radio will display a second three digit code. Write the second code down. You will now have a six digit code.
Step 4: Call the Chevy Radio Code phone line at 1-800-537-5140.
Step 4: Enter 106010 followed by the # key to direct you to the radio code retrieval system.
Step 5: Enter the six digit code you retrieved in steps 2 and 3 followed by the * key. They must be in order. You will be given a four digit radio code. Write down the radio code.
Step 6: Start your vehicle and turn on the radio. Using the Minute and Hour buttons, enter in the four digit radio code to your stereo system. Press the AM/FM button to unlock your stereo.
How to Unlock a GM Radio Step 1: Start the vehicle and turn on the radio. The radio will display "LOC" indicating the Theftlock system is activated.
Step 2: Press and hold preset buttons 1 and 4 for ten seconds. (If you don't have a fourth preset button, press and hold presets 2 and 3.) The radio will display a three digit number. Write this number down.
Step 3: Press the AM/FM button. Your radio will display a second three digit code. Write the second code down. You will now have a six digit code.
Step 4: Contact your local GM Dealer and give them the six digit code. They will give you a four digit radio code.
Many dealers will give you your radio code for free, while others may charge a small fee. If your dealer is charging a larger fee, consider calling another dealer or doing a Google search for sites offering GMC Radio codes. They usually charge a small (around $10) fee.
Step 5: Start your vehicle and turn on the radio. Press the Hour button on the radio until the first two number of the code appear. Next, press the Minute button until the last two numbers of the code are displayed. Once all four digits appear, press the AM/FM button to unlock your stereo. The display will read "SEC" indicating you have successfully unlocked your radio and it is fully operational.
If radio display reads "INOP" while the vehicle is on, too many incorrect radio codes have been entered. To remove "INOP" from your display and unlock your radio, you must leave the key in the On position for one hour. Once you've retrieved your radio unlock code, write it down for future use. Your radio code will not change and having it handy will save from going from the radio code retrieval process again.

Unlocking the Delco Radio Theft-Deterrent Feature After a Power Loss

If you know the code that was used to lock the radio then use the following instructions from the owner's manual to unlock the radio.
Quote:
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 until the last two digits agree with your code.
4. Press HR until the first one or two digits agree with your code.
5. Press AM-FM after you have confirmed that the code matches your secret code. 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 more chances (eight tries per chance) to enter the correct code before INOP appears.
If you don't know the code that was used to lock the radio then you will have to use the dealer's unlock procedure as follows. The dealer code changes over time - the one listed is current as of this posting. If it doesn't work try 08359 or search the forum for messages with a more recent code.
Quote:
1. Press and hold presets 2 & 3 for about 10 seconds until the first three digits of the display code are displayed.
2. Write the numbers down.
3. Press the AM-FM button, write down the next three numbers.
4. Call 1-800-537-5140. When asked, enter dealer code 202108, press the * button, and enter the six digit code from the radio. You will get an unlock code, write it down.
5. Go back to the car, press the HR button and set the first two numbers, press the MIN button and set the next two numbers, then press the AM-FM button. The display will show SEC, indicating the radio is now operable and secure.

To remove the code, repeat step 5. you should see --- on the radio face indicating the code is now out of the radio."

you need to go to the dealer they will unlock it please read your owners manual about this hope this helps

2000 chevorlet monte carlo i put a radio in my car and it reads locked how do i unlocke it ?
i dont know the code.

www.radio-code.com and they have step by step instructions on how to unlock.

The radio comes with a preassigned lock code that must be obtained from Pontiac. They will need you to follow these steps to retrieve two sets of numbers for them to call GM and obtain the assign lock code for your radio. STEP ONE: Press number 2 and number 3 simultaneously. Hold until the first set of numbers appear. Then press the AM/FM button on the radio for the last set of numbers to appear. Give those numbers to Pontiac, and they will call for the radio lock code. They will also provide you the steps to enter that code to unlock your radio.

Radios in the 2004 Impalas are tied to the vehicle's VIN through the computer, so it may be somewhat difficult to get the code. However, the following steps should work:

1. Press and hold the buttons for presets 1 & 4 (may be 2 & 3). The word "SEC" should show.
2. Press the "MIN" button. "000" should be displayed.
3. Press the "MIN" button again to have the second two numbers appear. Record these numbers.
4. Press the "HR" button for the first two numbers to appear. Record these numbers. -- Note: Your number sequence should be the numbers from the "HR" button followed by the numbers from the "MIN" button.
5. Call 1-800-537-5140. This will get you to the GM unlock code automated line. Ignore the prompt and enter "202108#". Next enter your code (remember, HR then MIN) followed by the * key. For example, 1234*. A 3 or 4 digit code will be given to you. If you get a code such as 0532, drop the zero when entering it into your radio.
6. Enter the code into the radio IAW the applicable manual.