GMC Repair: service ride control, yukon xl, 2005 yukon xl

Question
2005 yukon xl denali. 3 days ago, felt like slight sway when changing lanes ( very slight ). today the message "service ride control" came up on dic. checked connections at shocks, all seemed ok, fuse (30 amp) under hood is ok. do not hear any motor running for leveling, but had not noticed it in last year of ownership very often. would like to know if there are any typical causes for this message or where i might begin testing to locate source of issue and repair.  any help/direction would be greatly appreciated.  thanks in advance.

Answer
well without knowing what code is set exactly it could be a few things, most common are, failed shocks, and rear compressor's for the leveling system.  if you can get the truck scanned for free at pep boys or auto zone then post the code i can lead you further