1997 Buick Century radio code loc

My Radio says LOC after loss Battery Power? How can I restore to normal?

If you don't have the unlock code (maybe the previous owner programmed one in, as they are not activated from the factory) you'll have to go to the dealer to get it unlocked. Check the glove box and console, maybe someone wrote the lock code they entered down somewhere (in owners manual, on a sticker inside glovebox door, etc...).