What makes the car stays in N for 10 seconds before going to D after starting it on 2005 Mercedes-Benz ML500

Why when I put the car on Drive, it stays not only in Neutraul for about 10 seconds then switch to drive. what is the cause?

Asked by for the 2005 Mercedes-Benz ML500
Possible trans fluid low? Any warning lamps on? If so what diagnostics fault # are present?