Changing BCM with Theftlock Radio?

I'm thinking about upgrading the BCM on my 2000 Pontiac Montana from version 3 to version 4. It has a newer RDS Theftlock radio, which I just purchased on Ebay and paid the dealer big bucks to unlock.

My question is, will changing the BCM lock up my Radio?

Thanks,
Rod

What year make and model was the radio out of.
If it is unlocked and working I would leave things as is.
The version 4 BCM just has all of the car anti theft in it.

The newer type radios are set up to read the PCM vin no and if it does not match the vin stored in radio it will shut down.

Theft Deterrent
The "Theftlock" theft deterrent system is a feature on all base and uplevel radios. There is no need to program a security code into the radio as in past model years. The theft deterrent system now utilizes class 2 serial data to determine if the radio is in the appropriate vehicle. Each time the radio receives the "run" power mode message, it compares the VIN information it has stored to the VIN information received from a module on the class 2 serial data circuit responsible for transmitting that information. If a mis-match occurs, the radio display will indicate to the user the radio is locked. Once this takes place, a DTC will set, the radio will not respond to any button presses and become inoperative.
The two scenarios able to cause this condition are:
A radio is installed from another vehicle.
A module which communicates on the class 2 serial data circuit which supplies VIN information to the radio is replaced and not properly setup with the correct VIN information for that vehicle.
The only way to unlock the radio is by using a scan tool. Always refer to the table to diagnose the "Theftlock" DTC for further information.

Old type theft lock radio.
http://www.automotiveforums.com/vbulletin/showthread.php?t=310354&highlight=theftlock

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.

It was from a 2003 Pontiac Grand Prix. And I followed all those instructions and even left the car ignition in on position for 2 hours and then acc for 2 hours. (others on other posts had mentioned that working for them) Mine actually said Locked, and would not respond to any key press.

I really want the #4 BCM so that I can have the light and horn confirmation.

Can I take the BCM to someone and have them program it to have my VIN?

If not, I suppose I'll have either give up, or replace it and then shell out another $100 to a dealer to have them reprogram it.

What would happen if I just tested the BCM on my van. Suppose it locked the radio, could I just put my old BCM back in to unlock the radio?

Thanks for your help.

It was from a 2003 Pontiac Grand Prix. And I followed all those instructions and even left the car ignition in on position for 2 hours and then acc for 2 hours. (others on other posts had mentioned that working for them) Mine actually said Locked, and would not respond to any key press.

I really want the #4 BCM so that I can have the light and horn confirmation.

Can I take the BCM to someone and have them program it to have my VIN?

If not, I suppose I'll have either give up, or replace it and then shell out another $100 to a dealer to have them reprogram it.

What would happen if I just tested the BCM on my van. Suppose it locked the radio, could I just put my old BCM back in to unlock the radio?

Thanks for your help.

If your radio displays theft lock it is the older style radio that doe not check the vin no.

Get it unlocked and program your own code into it or just turn off the theft lock and be done with it.
Good Luck
MT

Thanks. I'll look through my manual, but like I said it didn't respond to any of the methods above. It looks like the one on the upper right here. Except the tape deck says monsoon.

http://www.corvetteradios.com/radiolock1.gif

Here's the one I got.
http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&ih=001&sspagename=STRK%3AMEWN%3AIT&viewitem=&item=110124192009&rd=1,1

BTW, for anyone that cares, I changed my BCM and it didn't lock my radio. phew! That was a relief.