This code deal, if it is the same as for a GM product is set by the consumer. I used the last three digits on my old GM vehicle of my phone number. You have to put in the same three numbers, or it will not work. I am sure there is a workaround for it. But this is something that is set by the consumer. If you bought it from an individual, you will have to get the code. On the GM radio, there is a red light that blinked, if I remember right. I spent 99 bucks, put in Sony Xplode (nothing fancy because it's a Jeep), complete with a front aux port, and I play my Ipod through it. No more CDs!!!
2003 Rubicon, stock - but building - slowly... in Van Buren, AR
Though GM wasnt the only oem that used code protected radios, I have never seen on in a Jeep, Dodge, Chrysler, or Plymouth. Others under the DC Umbrella, ie Mercedes have been known to use code protected radios.
97 TJ, s35 Detroit, Open 30, 33"mtrs, 4" Skyjunker Lift, Kilby Tank Skid, Fabtech Steering Skid 2.5 Super Low Output 4 Banger