I don't have codes, but I drive a 2014 MKS and can give some suspension info. The 2013 MKS has adjustable suspension, but it isn't actually determined by putting the shift lever into D or S. Those are for throttle response/shifting etc. You assign suspension settings on the LCD screen to the left of the tach. It's under "drive mode" settings I think. There are 3 modes, Comfort - hilariously soft... normal - Medium setting... Sport - Stiff setting. You have to assign a mode to each of the shifter positions. I have D set to normal, and S set to Sport. On long road trips I will change D to Comfort. When I have the suspension set to Sport it feels too harsh going over speed bumps near me, so I just wanted to double check that you verified that S was set to sport suspension. It might sound super obvious, but I won't lie, it took me days to figure out. I tore through the touchscreen menus so many times before finding out that it wasn't in the touchscreen, but the small LCD menu instead.