How do i reset my radio in a 2002 cadillac

its locked... you need the VIN and call the dealer to give you the code

try using a code reader to reset the CPU as sometimes a battery change will corrupt the CPU program

Usually the warning means the alternator is not charging the battery.
Have you had the system tested ?

Did you replace those parts based on the trouble code? Or are you just throwing parts at it? What are the codes?

http://ricksfreeautorepairadvice.com/flashing-check-engine-light-is-serious/

You probably blew a fuse check them.

need to notify a dealer the [ loc ] code is part of security system if u have manual it will advise how to get radio id number which will also be needed or call dealer and will advise how to get radio id number

Anytime I get a too lean DTC I first change the fuel filter if it hasn't been changed in awhile. You'd be surprised how many times this has helped.

Good Luck with it.

Bob

IF when you purchased your car you didn't set your own personal code you will have to take this to your local GM dealer and they can pull the code that is set at the factory and unlock your radio.THe proceedure for setting your own code then unlocking radio is in your owners manual.The dealership I worked for did this for free.

it is under the rear seat passenger side