BMW audio circuit with anti-theft function, even if the thief stolen, as long as he does not know the password, the sound system will not work, and therefore can not be used. If the repair process, the demolition of the battery or remove the sound system circuit, after the repair is completed, you must follow the correct steps to enter your BMW car audio system password, the sound system to work properly.
    BMW anti-theft sound system manual with three card name, one is white, size and business card the same card. There are two main numbers: one is the car's password, it is composed of five digits, and each bit is between 1 to 6, the other is the sound system batch number, such as F21127929A. The card reads: When you enter the password, if you hear the "beep" sound, you should immediately stop and re-enter the first digit from the password; the other is a yellow square card, the middle of a key shape symbol , Indicating that if the sound system displays "CODE" should enter the password number to work.
    Please enter the password correctly
    (1) After unplugging the ignition key, on the left side of the panel of the audio system, there is a red anti-theft indication next to the ANTI-THEFT indicator. The LED will flash continuously and the user should pay attention to this feature.
    (2) after the key unplug, as long as the touch sound system button, the alarm is to turn on the ignition during the alarm switch.
    (3) As long as the sound system power supply voltage is lower than 5V, such as battery loss, battery removal, electronic equipment repair or demolition sound system and so on, the sound system will not work. When the power supply voltage returns to normal, the word "CODE" appears in the display, asking the user to enter the sound system password.
    (4) When the sound system is connected, if the display shows "CODE" characters, it should be entered in the order of the password provided by the white card. If you enter the correct password three times in succession, the sound system still does not accept it, you should wait for one hour after the input, during which the sound system does not accept any instructions, so all operations are futile. When entering a five-digit password number, it must be entered one by one. For example, the password number is 12345, you enter 125 instead of 123, then enter 45, a total of 5 digits, the sound system will not work properly. It is not possible to relieve the password by means of guessing, so the anti-theft sound system is of little use to the thief. When you enter the fifth digit of the password, if you hear the "beep" sound, you should stop immediately. When re-entering the password, enter from the first digit of the password.
    (5) white password card should be placed in a safe place, do not put in the car.
    (6) in the audio or electronic equipment repair, the password card should be to the repair shop, if not found or lost and BMW agents should contact.
    (7) For safety reasons, in any case it is best not to sound system password number to other people.