There is no way to remove that warning message from your DIC .. Keep in mind, this annoying message comes on for anything..
I mean, you can have a loose gas cap & this message will come on. It's annoying & wonder why GM never got around fixing it's flaws.
As for service suspension ride, it is exactly what is. There is something wrong in your suspension.
I removed my rear Stock suspension and added some after market ones that I can manually inflate (lower & lift at what ever point I want)
I got the error "service suspension".. Because I clearly removed the stock ones and the wiring/plug was just hanging in the rear.
Well it cost me $25.00 to remove the SS warning sign.
I bought this: