Radio displays LOC

Make sure the illumination wire is connected

dealership or a mechanic with a tech 2 scanner.

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/

The wires will be the same. The problem is that the radio you bought may have theftlock on it. ( it would be printed on the front). If so you don't have the code for it. there is a slight chance that it will work, probably 1 in a 100. If it doesn't and the display reads LOC not LOCK, then you can take it to a dealer and they can recode it for you. Costs about 50 dollars here. Indy

How to Reset GM Theft lock Radio's
Article Disclaimer: This article is meant to be used by Delco Radio owners to reset there radios. In no way is it meant to be used for any unethical or unlawful ways.

Purpose
The following instructions will allow you to reset any GM (General Motors), Cadillac, Oldsmobile, Buick, Pontiac theft lock radio.

Requirements
The theft lock radio must be in "LOC" mode.

Procedure:
1. Turn the ignition ON (The radio should display "LOC")
2. Hold down the Radio Presets 2 and 3 buttons for six seconds
3. The radio display changes from LOC to a three-digit number. Write this number down. You now have fifteen seconds to complete the next step.
4. Press the AM/FM button
5. The radio display changes to another three-digit number. Write this number to the right of the first one
6. You now have a six-digit number, the first three digits are from STEP 03 and the last three digits are form STEP 05
7. Call 1-800-537-5140
8. Press 1 then # (pound). You'll hear "Invalid Code, try again"
9. Press 139010 or 106010 or 206010 or 202107 then # (pound). You will be asked to enter your four or six digit code followed by *
10. Enter the number from STEP 6 then *
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.

Dealership Codes
139010
106010
206010
202107

Troubleshooting
If you fail to enter the correct code eight times, the radio goes into INOP mode. You have to wait an hour with the ignition on before the radio returns to LOC mode.

To Read the original article or read similar articles please visit kingbain.com/how-to/unlock-gm-theftlock-radio-s

Good luck (remmeber comment and rated this).

replace the factory radio which is not cheap. I would go have an aftermarket radio put in it would be alot cheaper.

Yeah you need a new CD player common on those trucks but be careful the RDS radios must be programmed if get a used factory radio

the loc code is set the first time the radio is turned on. if you don't know the code there is no legal way to unlock it with out the tools at the dealership.

some factory radios wont play burnt cds,dont know if thats the case?but i not the case the optcal lens in side the radio is bad got one id sell you out of a 05 ha ha.

Search the net for "Delco unlock codes" OR "Delco security codes" you should easily find a set of instructions telling you to get a code from your radio and then call an 800 number. Follow these instructions. This will give you the factory unlock code for your stereo. Worked for me and for heaven sakes don't pay anybody for this information - it's free.