I found this information:
Delco Lock II (also called Theftlock), the next generation of anti-theft controls, features an owner-programmed lock code which is entered through the radio controls. If the customer programs a lock code into the radio and memory power is lost, "LOC" will appear after power is restored. The locking code must be entered to allow its use. If the customer does not have the code number, the radio may be unlocked by an authorized General Motors facility using special access codes.
Since there are numerous radio systems available, it is important to obtain the RPO codes from the decal on the vehicle. Radio codes start with the letter "U." Compare these codes with your repair manual to match the systems and service procedures.
They claim to be able to give you your unlock key, but I can't make any promises! But hey, it's only 2.60, better than $60!
Sunday, January 13th, 2008 AT 12:00 AM