My audio system is stuck in the 'loc' position. We didn't have a code so we can't unlock it. Suburban

i guess this is one of the first locking radios ever at gm

https://www.youtube.com/watch?v=u2osiPwVNm8


http://chevroletforum.com/forum/tahoe-suburban-25/%22l-o-c-%22-stereo-screen-menu-17934/


try googling this, see what others did,

only GM can unlock this rad, call them.

there may be hacking sites that can but i dont use or trust them.

That is a security "feature" on GM radios to deter theft. The following instructions has had sucess with other GM vehicles. If not, only a dealer has the equipment to get past lock screen.

This works on vettes with theftlock. Try it on the tahoe and let us know....




The following procedure will give you a new code that you can use instead of your personal code. Using this new code, you can "unlock" your radio and then "re-lock" it with a new code if you wish. Prerequisites: The radio must be in LOC mode NOT in INOP mode. Let me explain. If you have activated the Theft-Deterrent feature of your radio and loose power, the radio goes
into LOC (theftlock) mode. With the ignition on, you must use the MN and HR buttons to enter you personal code in order to unlock it (The instructions are on page 3-27 in your Y2K Owner's manual). If you fail to enter the correct code eight (8) times, the radio goes into INOP
mode. You have to wait an hour with the ignition on before the radio returns to LOC mode (go for a long drive somewhere).

Procedure: 01. Turn the ignition ON (The radio displays LOC)

02. Hold down the Radio Presets 2 and 3 buttons for six seconds

03. The radio display changes from LOC to a three-digit number. Write this number down. Don't take forever, fifteen seconds max before the next step.

04. Press the AM/FM button

05. The radio display changes to another three-digit number. Write this number to the right of the first one.

06. You now have a six-digit number, the first three digits are from STEP 03 and the last three digits are form STEP 05

07. Call 1 800 537 5140

08. Press 1 then # (pound). You'll hear "Invalid Code, try again"

09. Press 139010 then # (pound). You will be asked to enter your four or six digit code followed by * (start)

10. Enter the number from STEP 6 then * (star)

11. Listen to the four-digit number and write it down. It will be repeated twice

12. Turn the ignition ON (The radio displays LOC)

13. Use the MN and HR buttons to enter the code from STEP 11

14. Press the AM/FM button. The radio display changes to SEC Your radio is now "un-locked" and usable. The Theft-Deterrent feature is STILL active! If you want to disable it, use the instruction on page 3-27 in your Y2K Owner's manual. Use the code from STEP 11 instead of your personal code. Note: This tip originated from LOTZAHP, Austin TX (credit must be given where credit is due). I verified it on an Y2K C5 with a locked radio - mine.
http://chevroletforum.com/forum/tahoe-suburban-25/help-radio-locked-8220/

if you get to step 4 email the code to me at [email protected]


Service Information

1999 Chevrolet Chevy K Pickup - 4WD ' Escalade, Pickup Classic, Suburban, Tahoe, Yukon VIN C/K Service Manual ' Document ID: 522597 Radio Displays LOC, LOCKED, or CODE Step
Action
Value(s)
Yes
No
1

1. Turn the ignition off.
2. Disconnect the negative battery cable for 1 minute.
3. Reconnect the battery cable.
4. Turn the ignition to run.
5. Turn the radio on.

Does radio now operate?
--
--
Go to Step 2
2
Important: It will say Theftlock® on the face of the radio.
Does the Radio have Theftlock?
--
Go to Step 3
--
3
Is it possible to get the security code from the customer?
--
Go to Radio/Audio System Operation
Go to Step 4
4

1. Turn the ignition on.
2. Turn the radio off.
3. Depress and hold Pre-set buttons 2 and 3.
4. Write down the first three digits that appear on the radio display.
5. Depress AM/FM, write down the second three digits that appear on the radio display.

Did you receive the 6 digit Radio Display Code?
--
Go to Step 5
Send Radio in for repair
5
Contact Delco Assistance to obtain a "Radio Back-up Code".
--
Go to Step 6
--
6

1. Use the hours and minutes buttons on the radio and install the 4 digit "Radio Back-up Code".
2. Depress the AM/FM button.
"SEC" should display.

Did the radio unlock?
--
Go to Step 7
Repeat Step 6
7
Important: This will remove the original owner's code. The owner will then be able to reinstall their own personal security code.
Step 6 only unlocked the radio, if the original code is not known, repeat step 6.
Did the radio display?
--
--
Repeat Step 7

Radio code is specific for each and every car. It is specific like anti theft code.

You can get it by providing your VIN# and registration details in authorized dealership. Nobody else can provide you. If anybody can provide you that , then there is no meaning of security for your car.

Hello, you will need to enter your radio unlock code using these instructions.

1. Press SEEK DOWN, SEEK UP, TUNE DOWN, or TUNE UP. The radio display should show 0000.
2. PRESS SEEK DOWN to set the first digit.
3. Press SEEK UP to set the second digit.
4. Press TUNE DOWN to set the third digit.
5. Press TUNE UP to set the fourth digit.
6. If the code was entered correctly, the radio will display SEC (SECURE). The theft deterrent system for the radio is now active and normal operation may be resumed. If the code was entered incorrectly, the radio will display Err for 5 seconds and the LOC (LOCKED) will be displayed again. If LOC is displayed, repeat 1-6.
7. If the correct code is not entered in 8 attempts, follow the next steps:
7.1. Turn ignition to ACC position. 7.2. Turn radio power switch OFF. 7.3. Wait one hour before repeating steps 1 through 7. If attempts to unlock the system are made before the one hour period is up, the radio will display INOP (INOPERATIVE). Continue to wait. If the ignition is not in the ACC position, power will never reset internally to allow itself to be unlocked. 7.4. After one hour, repeat steps 1-7.

Unlocking the system from the manual.
1. Turn on ignition. LOC will appear.
2. Press MN and '000' will appear.
3. Press MN again and hold until you see the last 2 digits of your code.
4. Press and hold HR until you see the first 1 or 2 digits of your code.
5. Press AM FM after you make sure the code is correct. SEC should appear, meaning your system is ready and still secure. If LOC appears, the code was wrong. Good luck

take ur vin number - call the local dealer - ask how to put the code in and the code for ur car - truck - -
also ask about recalls -

if the radio didn't come from ur vehicle - write GMC - all u can do -

You will need an unlock code for radio. Either found in vehicle manual or will need to get it from the dealer.

you have locked the radio and will need to leave the ignition on for one hour to let it reset, then push 5&6 to get the code.  Radio should display --- and will let you try 3 codes then loc will display for one hour.  Just turn on the ign with engine off and pull parking brake to kill the drl lights.  And don't leve it unattended ;)   the code will need to be called in to obtain the unlock code.

power radio on then hold 2 and 3