How To Reset the Service B Light in a Mercedes E320

1. Climb into the vehicle and close the driver's door.
2. Switch the ignition key to the second position. Within four seconds of switching the ignition key to the proper position, press the '0' button located on your left-side instrument panel four times in rapid succession.
3. Turn off the vehicle's ignition.
4. Press and hold the '0' button while turning the vehicle's ignition back to the second position. Continue holding the '0' button for 10 seconds or until the display reads 'SERVICE IN'.
5. Release the '0' button, turn the ignition to the off position and start the vehicle to verify that the service message has cleared.