Mahmud,
You do have self leveling suspension. The picture is for Adjustable ride height and is standard is most 4.6 and 4.8 vehicles. I had the same message on my truck a few months back and it was because mine had a slow leak. Take it to the dealership or an independent and have them run the code. It does not stop your from driving the car but my back wheels dropped down a little which made the ride really bumpy in my truck.

Good luck!

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Abster641