Volkswagens have an antitheft feature built into the radio. Every time you turn off the radio and remove the key, a red light in the face plate will start to blink: this signals that the radio is in antitheft mode. Anyone who does not know the radio code can't operate it if it is removed from the car. However, the radio also goes into this mode whenever the battery is disconnected, an electrical fuse is blown or you disconnect the radio from the current supply. You may need to reset the radio if this happens.
When the word "SAFE" appears on the radio display when you turn the radio on, it means the radio will only work once you enter the correct code. Find the code in the instruction booklet that came with your vehicle: it should be on the Radio Card, next to the table of contents.
Press the "MODE" and "SCAN" buttons simultaneously and hold them until "1000" appears on the radio display. Release the buttons as soon as this number appears.
Refer to your Radio Card and use the station buttons ("1", "2", "3" and "4") to input the code. Use the "1" button to input the first digit of the code, the "2" button to input the second digit, and so on.
When the code appears on the display, press the "MODE" and "SCAN" buttons simultaneously and hold them until "SAFE" appears on the radio display. Release the buttons as soon as this appears.
A frequency will appear on the display, and you can use the radio again.
If you do not have the user manual that came with your Volkswagen, or otherwise have lost the radio code, you may need to remove the radio unit, get the its serial number and call your Volkswagen dealer.
If you enter the radio code incorrectly twice in a row, the radio will lock for one hour, preventing you from using it or re-entering the code.