Stereo code for 1998 chevy blazer

Here you go.

Question edited for clarity and add maker.
Question moved to make model category.

LOC is LOCked. This is the three ways to get a radio code.

https://www.fixya.com/support/r29874205-need_vehicle_radio_code

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I don't think you can on that vehicle-probably not a code, anyway. Check the fuel pump relay, it may be stuck on. Should be located in the power distribution box under hood. Pull it out-pump should stop-swap in a different relay to test. If pump still runs on with new relay, the wiring to the relay needs checked.

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.

Read more: http://wiki.answers.com/Q/Code_to_unlock_radio_for_Chevy_blazer#ixzz26wZKnNnU

here are two definitions.
First: ignition coil module 4 times ref circuit intermittent no pulses.
Second: Distributorless ignition system 4 times signal interrupted.
You will want to inspect the spark-plugs, spark-plug boots, Coils for defects. Let me know how it goes.

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.

this happened to me. there is a code you have to enter. I bought my blazer used and didn't know the code so i took it to a dealer. they will retrieve the code, unlock it and then YOU write it down in your manual for future use!

You can call up the dealer and see how much it's going to cost there for the codes, but try 0000 first. If that does not work. try www.radio-code.com they can get your radio working again. Good luck and keep me posted

You must bring the the car to a geo/chevy dealer so they can reset the radio to factory unlock. It might be cheeper to have a new cd radio installed best by is a good place for around $200 a radio can be purched and installed .

call your GM dealer and they should give you the code over the phone and walk you thru the problem