Installing your car radio's unlock code is a simple and straightforward procedure. You must have the unlock code on hand so you can enter it into the system. Entering the unlock code makes your car radio operable again. The antitheft feature on your car radio locks down whenever your car's battery dies or when someone takes the radio out its harness.
Look through your car's user manual for an antitheft card, which displays your radio's serial number and unlock code. If you have the serial number, but not the unlock code, contact your radio manufacturer.
Ask for an unlock code. Provide your radio's serial number. This gives the manufacturer proof that you own the radio.
Insert the key in the ignition. Switch it to "ON" and wait for your radio to turn on. It should display either "Locked" or "Code."
Press and hold the "Tune" button. Enter the code with the numerical buttons. Your radio will now unlock.
Entering the code wrong will lock your radio permanently.