System Operation: DSC
DSC uses the brakes and powertrain torque control to help maintain the lateral stability of the vehicle. While the ignition is on the DSC function is permanently enabled unless selected off by the DSC switch. Even if DSC is deselected, driving maneuvers with extreme yaw or lateral acceleration may trigger DSC activity to assist vehicle stability.
DSC enhances driving safety in abrupt maneuvers and in understeer or oversteer situations which may occur in a bend. The anti-lock brake system (ABS) module monitors the yaw rate and lateral acceleration of the vehicle, and the steering input, then selectively applies individual brakes and signals for powertrain torque adjustments to reduce understeer or oversteer.
In general: in an understeering situation, the inner wheels are braked to counteract the yaw movement towards the outer edge of the bend; in an oversteering situation, the outer wheels are braked to prevent the rear end of the vehicle from pushing towards the outer edge of the bend.
The anti-lock brake system (ABS) module monitors the tracking stability of the vehicle using inputs from the wheel speed sensors, the steering angle sensor and the yaw rate and lateral acceleration sensor. The tracking stability is compared with stored target data and, whenever the tracking stability deviates from the target data, the anti-lock brake system (ABS) module intervenes by applying the appropriate brakes. On vehicles with an automatic transmission, when the DSC function is active, the anti-lock brake system (ABS) module also signals the transmission control module (TCM) to prevent gear shifts. If necessary, the anti-lock brake system (ABS) module also signals:
- The engine control module (ECM), to reduce engine torque.
- The transfer box control module, to adjust the locking torque of the center differential.
- The rear differential control module, to adjust the locking torque of the rear differential.
The DSC function overrides the differential locking torque requests from the terrain response system.