Directly from their press release on vsa with traction control:
Advanced Vehicle Stability Assist™ (VSA™) with Traction Control
Vehicle Stability Assist (VSA) is an Electronic Stability Control system that works in conjunction with the Civic's Drive-By-Wire™ throttle system and its 4-channel ABS systems to enhance control while the vehicle is accelerating, braking, cornering or when the driver makes a sudden maneuver. VSA functions by applying brake force to one or more wheels independently while simultaneously managing the throttle, ignition and fuel systems to help the vehicle maintain the driver's intended path of travel.
The VSA system constantly analyzes data from six sensors that monitor wheel and vehicle speed, steering input, lateral G forces and yaw rate. VSA compares the driver's inputs with the vehicle's actual response. Whenever the actual response falls outside of a predetermined acceptable range, VSA intervenes with a corrective action. For example, if VSA detects an oversteer condition, the system may apply braking force to the outside front and rear wheels to counteract the unintended yawing effect. In the event of understeer, VSA may apply braking to the inside rear wheel while reducing engine power to help return the car to its intended course.
VSA also provides a limited-slip differential effect for the front wheels by applying braking force to a slipping wheel, thereby redirecting driving force to the wheel with more traction. VSA is calibrated to function in a nearly transparent manner, and in many cases a driver will not be aware of its operation. However, any time that the system is enhancing vehicle stability, an indicator light flashes in the instrument cluster. While the driver can deactivate the VSA stability enhancement and traction-control functions via a switch located on the instrument panel, ABS remains fully operational at all times.
Honda is applying a new and additional type of control algorithm to the Vehicle Stability Assist® (VSA) system for the 2012 Civic that enables more responsive handling under icy or slippery conditions. The concept for this additional algorithm is based on patented Honda know-how gained from its humanoid robotics research and development work.
The conventional VSA feedback loop, which operates by comparing the actual vehicle course with the intended course based on an ideal vehicle response, is augmented by additional control applied via a secondary feedback loop. This additional feedback loop is a type of filter that in effect quickens the estimation of the intended path – based on the driver 's inputs – and acts in parallel to the conventional "actual versus intended course" stability control, and is used to augment that control.
Like conventional VSA, the additional control loop also considers steering wheel angle, yaw rate, wheel speeds, throttle pedal angle, vehicle acceleration and other variables. It then lightly brakes individual wheels as needed, to predictively control the vehicle along its intended path, and is able to induce more yaw more quickly than conventional VSA on low friction roads.
This advanced VSA system control loop results in faster reacting stability control and reduced transient understeer which may occur on icy or other slippery roads, compared with the previous Civic VSA system. This makes the vehicle more responsive, improving path accuracy, and enhancing the fun-to-drive character that is a trademark of Honda vehicles.
I have 20k miles on my Si and more often than not I have TC off. ABS remains functional. The only reason to pull the ABS fuse would be on a track where ABS could hinder track times. All said and done just be smart and be familiar with your car. Too many people find out too late that their limits run out well before the car's does.
