trying to get the codes out of stereo

[jlvsprljam]

i have a 2000 cavalier and had to replace the factory cd player with one from a junk yard and it just says LOC i know about hitting the 2 and 3 preset buttons to get the code out of it but its not giving me any code, what might i be doing wrong.
thanks

[jlvsprljam]

sorry for such a short explaination yesterday, i was trying to get my problem up on here while i was at work and i got something i needed to get done. but ive tried pushing the 2and 3 preset buttons and i cant get anything to show up. ive tried it with the key off, the key on, the car started, ive unplugged it and tried right as i plugged it in with the key of and on and i have been unable to get anyhting to come up on the screen except for LOC while the key is on. any help will be greatly apreciated
o yea and incase it matters i have a 2000 cavalier but the stereo im trying to install is from a 2002.
thanks in advance
later

[wlmp]

Pressing buttons 1 and 3 together does not make the stereo give you any codes. if it did gms design of the theftlock would be pointless. you press 1 and 3 when you want to enable the theftlock for yourself with your own 3 digit code. if when you power up the radio you have and it says LOC that means the theftlock was enabled when you got it and no matter what you must have the proper code to make it function again, keep in mind trying too many times at guessing the code will render it inoperable(depending on type of radio we are dealing with). If you purchased this radio and have a receipt to prove or can get a receipt I believe the dealer has a way to access the code, actually they must have a way because all the leased vehiles that get returned probably have the theftlock turned on and the dealer is not going to call the first leasers to get the code. I hope this helps ya!

[wlmp]

wlmp again, I forgot to ask you is this stereo an older model or the new type(is this stereo a direct replacement for your current 2000 cavi) if it is a new type it will not work in your car period. gm has done something really stupid by means that the stereo learns part of the vin number of the vehicle it was originally installed in so that it can be used only in that vehicle. If you put it in another vehicle it will say LOC. Iam not sure if the dealer can fix that for you or not!