How do i reset my radio in my 2004 envoy after i replaced my battery?

To reset the radio in your 2004 GMC Envoy after replacing the battery, first, turn on the ignition without starting the engine. Then, turn on the radio; if it shows "LOCKED" or "SECURITY," you may need to enter a security code. If you don't have the code, check your owner’s manual or contact a dealership. Once entered, the radio should reset and function normally.