How to Decode an Old BMW Radio

1. Enter your car. Insert the key in the ignition. Leave it in the 'OFF' position.
2. Locate the 'M' button on your radio. Press and hold it.
3. Turn the key to the 'On' position. Turn on the radio with the 'M' button pressed.
4. Write down the serial number that displays on your radio. Contact your BMW dealership. Ask for the unlock code.
5. Provide your serial number. Write down the unlock code.
6. Press and hold the 'Tuner' button. Enter the unlock code. Wait for the radio to turn on once you entered the code.