How to Reset a Mercedes M Class Radioby Cassandra Tribe
It may be necessary to reset a Mercedes M Class radio should the radio or battery be disconnected or the battery become completely drained. When the radio receives power again, it will be in a locked and unusable state. The LCD display will read "Enter Code." The security code assigned to the vehicle must be entered to reset the radio and unlock it.
Disconnect the negative cable from the battery with a socket wrench and then disconnect the positive cable as well. Wait 30 minutes to allow for the vehicle's emergency power store to discharge completely before proceeding with the project.
Reconnect the positive cable to the positive terminal on the battery with a socket wrench and then reconnect the negative cable to the battery.
Punch in the five number vehicle security code on the radio keypad. The security code is included with the owner's manual.
Call a local Mercedes-Benz dealership and give them the VIN of the vehicle and the radio's serial number to receive the code if the manual cannot be located. The radio's serial number can be found on the identification plate located on the underside of the radio. Pull the knobs off the radio, remove the face plate by prying it off by hand and the radio may be pulled out far enough to read the plate.
- If the wrong code is entered, wait an hour for the error message to clear before trying again.
Things You'll Need
- Socket set
- Security code
- Radio serial number (if needed)
- VIN number (if needed)
- Mercedes dealership contact number (if needed)
- Do not attempt to remove the radio and install it in another vehicle. While the security code will unlock it for use in the new vehicle, the security system in the original one will disable the car and it cannot be unlocked without the radio installed.
Cassandra Tribe has worked in the construction field for over 17 years and has experience in a variety of mechanical, scientific, automotive and mathematical forms. She has been writing and editing for over 10 years. Her areas of interest include culture and society, automotive, computers, business, the Internet, science and structural engineering and implementation.