2000 deville - service stability system indicator

I have a 2000 deville with 40,000 miles on it. Runs great.

One problem is that I always get a "service stability system"
indicator. If I clear the display, it goes away until I turn off the
car and start it again. I have had the car serviced and the back
shocks replaced (these shocks are filled with air) and still the
message appears. I strongly suspect that there is indeed no problem
with the stability system (at least there doesn't appear to be one when
I drive).

Does anyone have any knowledge or suggestions?

Thanks.