The ECS button will toggle between sport and tour mode on the suspension. Sport is firmer and tour is softer. The Sport/tour toggle switch near the ignition switch will make your exhaust louder or quieter. Sport is louder, tour is quieter. A lot of the active exhaust systems on our cars seize up at the back and stop working. There is an electric valve in the exhaust just before the muffler on the drivers side at the back. Sometimes the valve can be loosened up with PB Blaster etc to get it working again. The ECS suspension system is kind of complicated but there is lots of info here to read on and test etc. Good luck.