I purchased a 2000 C-5 a couple of weeks ago. I want to disconnect the battery. I’m not sure if there had been a security code entered into the radio by the previous owner. Is there a way to tell before I disconnect the battery? Are there any other precautions that I need to take before disconnecting the battery?

 

Ive disconnected my battery several times and have never had a problem with the stereo. Actually it remembers the radio stations when disconnected. My thinking is (and it may be wrong) that you need the stereo code if you remove the stereo.

When disconnecting the battery, always remove the negative side first. That's the only precautions I can think of.

 

There is a good discription in the owners manual on Radio Security codes. But if one is installed you will have to put in the code to clear the display after the battery is disconnected. If you have a flashing/blinking red light over the radio when the car is off and key rermoved then the security features are set.
George

 

I bought my 2K c-5 used a few weeks ago. I asked the dealer to reset the security code to the default. They said this could only be done when the radio is in the lock out mode. I guess if I disconnect the battery I will have to go back and have them reset it. Any one have any other suggestions?

 

Notes:
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. Thank you LOTZAHP for saving me +$70 from the dealer who wanted 45+ minutes labor time to take the radio off the car in order to get the serial number and then call GM for the “unlock” code.

I don’t know how to add it to the C5 FAQs. If someone does, please post it. I believe it is something that many people can use.

The following procedure will give you a new code that you can use instead of your personal code. Using the 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 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 [/b]six-digit number[/b], 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 *
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. You have forgotten it right, that’s why you are following these instructions.

Have fun!


[Modified by Hex29A, 12:27 AM 4/18/2002]