Operation that is not "System Error": TCS

During TCS operation, body and brake pedal lightly vibrate and mechanical noises may be heard. This is normal.
Depending on road circumstances, driver may have a sluggish feel. This is normal, because optimum traction has highest priority under TCS operation.
When vehicle is passing through a road where surface friction coefficient varies, downshifting or depressing accelerator pedal fully may activate TCS temporarily.