Dynamic Stability Control

The Dynamic Stability Control (DSC) uses the brakes and engine 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.

The DSC enhances driving safety in abrupt maneuvers and in understeer or oversteer situations that may occur in a bend. The Anti-lock Brake System (ABS) control module monitors the yaw rate and lateral acceleration of the vehicle and the steering input, then selectively applies individual brakes and signals for engine 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 ABS control module monitors the tracking stability of the vehicle using inputs from the wheel speed sensors, the steering angle sensor and the Restraints Control Module (RCM) (yaw rate and lateral acceleration data). The tracking stability is compared with stored target data. Whenever the tracking stability deviates from the target data, the ABS control module intervenes by applying the appropriate brakes. When the DSC function is active, the ABS control module also signals the Transmission Control Module (TCM) to prevent gear shifts and the Instrument Cluster (IC) to flash the DSC warning indicator.

If necessary, the ABS control module also signals:

• The Powertrain Control Module (PCM), to reduce engine torque.
• The Transfer Case Control Module (TCCM), to adjust the locking torque of the center differential.
• The Rear Differential Control Module (RDCM), to adjust the locking torque of the rear differential.

The DSC function overrides the differential locking torque requests from the Terrain Response (TR) system.

If DSC is selected off, a DSC system off message is displayed in the IC message center. For additional information, Refer to: INSTRUMENT CLUSTER .