Only for BMW radio with coding
The radio receiver security coding prevents unauthorized use of the radio receiver after the power supply has been disconnected. The power supply is interrupted, for example, when the battery is disconnected, when the radio receiver is removed, or when the radio receiver fuse blows.
If a security code has been entered into the radio, you must know this code before disconnecting the battery or removing the radio. If the code is unknown, the radio can only be put into operation at a BMW service station.
The individual code number is indicated in the radio receiver passport. The passport should not be kept in the car.