Roll Stability Control (RSC)

The RSC system monitors information from the wheel speed sensors, the throttle position sensor, the steering wheel rotation sensor (steering wheel angle and rate of change) and a yaw rate sensor that measures the change in vehicle direction. If the RSC system determines from all these inputs that conditions exist for a potential roll over, the system adjusts the brake torque at specific wheels in response to direct measurement of the vehicle roll motion and reduces engine torque to make the vehicle more stable. By adjusting brake torque, the system can reduce the cornering forces and, therefore, the total roll moment acting on the vehicle. Systems with RSC have an additional roll-rate sensor located within the stability control sensor cluster and additional programming within the ABS module to help control the vehicle during sudden maneuvers.

The RSC system constantly monitors the vehicle motion relative to the intended course. This is done by using sensors to compare the steering input and brake application with that of the actual vehicle motion. The system does not activate when the vehicle is traveling in reverse; however, the standard ABS and traction control continue to function as usual.

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

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

Some drivers may notice a slight movement of the brake pedal when the system checks itself. The brake pedal moves when an active test of the brake booster is run. During this test a small amount of pressure is generated at the master cylinder, but no pressure is generated in the brake calipers.