Service "D" reset procedure

  mercedes/s-class/2006-2013

This 2009 S550 4matic is 24,500 miles overdue for service D. Repairs overdue have been addressed an brought up to date, but when using telephone answer button, on steering wheel,and OK button at same time, does not give access to ASSYST program as I expected it to do. The car automatically applies brakes and triangle warning light appears on instrument panel. I have the iCarsoft MBII scanner and erased all codes after repairs, including ABS module repair and ECM repair.
What is the correct procedure for resetting Service D??

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