Roll Stability Control (RSC)

The ABS module monitors the roll-rate sensor and existing stability assist sensors and calculates if the vehicle may be approaching a situation where rollover is probable. If such a situation exists, the ABS module activates the RSC system to apply preemptive action. When activated, the RSC system adjusts the brake torque at specific wheels in response to direct measurement of the vehicle roll motion. By adjusting brake torque, the system can reduce the cornering forces and, therefore, the total roll movement acting on the vehicle. Vehicles with RSC have an additional roll-rate sensor located within the sensor cluster and additional programming within the ABS module to help control the vehicle during sudden maneuvers.

The ABS module constantly monitors the vehicle motion relative to the intended course. This is done by using information from the wheel speed sensors, the throttle position sensor, the steering wheel position sensor, the steering wheel rate of change and a yaw rate sensor that measures the change in vehicle direction. The ABS module compares the sensor information with that of the actual vehicle motion. If the module determines from all these inputs that conditions exist for a potential roll over, the system applies one or more brakes and reduces engine torque to make the vehicle more stable.

The RSC system does not activate when the vehicle is traveling in reverse; however, the ABS and traction assist continue to function as usual.

When the RSC system activates, any of the following can occur:

• A rumble or grinding sound much like ABS
• A small deceleration or a reduction in the acceleration of the vehicle
• The stability assist indicator flashes
• A vibration is felt in the pedal much like ABS
• If the event is severe and the driver's foot is not on the brake, the brake pedal moves to apply higher brake forces. A whooshing sound can also be heard from under the instrument panel in an event this severe