Method 1

Switch ignition on.
Locate the left instrument cluster button (service interval button). See Fig 1. Press (tap) the button twice, within 4 seconds of switching on the ignition.
Switch ignition off, within 4 seconds of tapping the button.
NOTE: Although the OEM claims that 4 seconds is the appropriate time interval in steps 2 and 3, aftermarket information indicates that performing the procedure as quickly as possible (2 sec.) will be more successful.
Push and hold in the left instrument cluster button (service interval button) and switch ignition on.
Hold the left instrument cluster button for another 10 seconds.
When the wrench symbol flashes, the system has been reset.

Fig 1: Identifying Left Instrument Cluster Button (Service Interval Button)

Courtesy of MERCEDES-BENZ OF NORTH AMERICA.