Truck radios says LOC

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 ignnition on before the radio returns to 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 ignnition on before the radio returns to LOC mode.

http://www.impalaforums.com/chevy-impala-8th-gen-discussion/270328-how-to-reset-gm-theft-lock-radios.html

its making my truck die - What does that mean? Is the truck's engine shutting down while it is running, or is the battery being drained such that the engine will not start?
Is the radio ON even when the ignition switch is turned off? Your radio power wire may be connected to a point that is always on instead of to a point that is controlled by the ignition switch.

if this is a factory radio, then you can go to dealership, to get unlock code for your radio. i think you may need the vin number.

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).

My dealer wants $85 for the code. Another dealer - 2 hrs away - wants $50. This looks more like a GM money-maker than a security feature.

This is posted at: http://wiki.answers.com/Q/Code_to_unlock_radio_for_Chevy_Blazer
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.

try code 0000, this is the stock code, unless someone has changed it. also you can go to www.radio-code for info on all codes

Hello, You will probably have to get the code through your local Chevrolet dealer.
CYA, Gator241

I had the same problem with my 1999 Sonoma. try this:
(You must be in your truck with a cell phone handy)

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 in your Owner’s manual. Use the code from STEP 11 instead of your personal code.

Hope it helps.