First, did you do the services the car required? The reset on the Mercedes is long and sometimes takes several attempts.
Displaying remaining distance, remaining time or service exceeded when vehicle stationary or when driving on driver request:
Wake-up instrument cluster. Start switch in position "2" or driving. Operate reset button for trip counter twice within 1 s: the current remaining distance, the current remaining time or the current service exceeded appears. Displaying oil level at driver request:
After start switch in position "2", wait 10 s until "DISPLAY OIL LEVEL" text and oil can symbol (or oil can and clock symbol) appears. Press reset button for trip counter twice within 1 s: the message "OIL LEVEL OKAY" (or "O.K.") or the current missing oil quantity appears. If correct oil level measurement is not possible, the text "OBSERVE WAITING TIME" appears (or the clock symbol and the oil can symbol; the clock symbol flashes). (The texts in parentheses relate to vehicles without multifunction display.)
Resetting ASSYST after oil change (oil change reset) at instrument cluster:
Move start switch into position "2". Within the first 4 s after moving start switch into position "2": press reset button for trip counter twice within one second. The display for the service request is thus activated for 10 s. Within these 10 s move start switch into position "0". The service request continues to be displayed. Press reset button for trip counter and hold pressed. Move start switch into position "2". Continue to hold reset button for trip counter pressed (about 10 s) until the signal sounds and the new start distance appears in the display.