The BMW E-30 comes equipped with an antitheft radio system. If at any time the power to the radio is interrupted, the radio will lock and to use it again, you must enter the security code. A dead battery, disconnected battery cable or removal of the radio are all possible causes for a power interruption. Whatever the cause, you'll want to be able to enter the code to start listening to music, news and sports again.
Turn the vehicle's ignition to the "On" position. Turn on the radio. You should see the word "Code" on the radio screen, indicating that you need to enter the unlock code.
Use the pushbutton selectors found at the bottom of the radio to enter the code. Each digit of the code refers to the location of a push button, running from left to right. For example: if the code is 4-3-5-1-2, you will first press the fourth button, then the third button, and so on until you have entered all five digits.
If the radio will not accept the code, proceed to Step 3.
Turn the ignition to the "On" position and leave it for one hour. If there have been three unsuccessful attempts to enter the code, you must allow the radio to reset.
Enter the code as described in Step 2. If at any time while entering the code you hear a beep, stop entering the code and begin again.
Do not store the radio code inside the vehicle. If you make a mistake while entering the code, continue the entry until you have entered five digits. The radio will alert you that the code is incorrect and you may try again.