2001 Buick Lesabre with an AIRBAG light on...and also the radio is in the LOC mode.

General Motors has designed in a lot of stuff to separate you from your money after the sale on their new cars. On '01 models they were just getting started with these customer-unfriendly business practices. Someone entered a code into your radio to activate their anti-theft system. If you don't know that code, you will have to go to the dealer. They can get a different code out of it, call a secret phone number to have the code translated to the needed code. Of course they don't do that for free.

For the Air Bag light, start by checking the fuses. There will always be two so if one blows, the other circuit will still run the warning light. Very often fuses blow when you jump-start the dead battery or connect a battery charger. That is just a nuisance problem caused by the current surges from computer memory circuits charging up.