BMW - Dynamic Stability Control
The DSC (Dynamic Stability Control) is BMW's electronic stability control system. It controls the suspension with the help of three other single programs – ABS (Anti-lock Brake System), ASC + T (Automatic Stability Control + Traction) and CBC (Cornering Break Control).
The system was firstly introduced back in 1997 offered on BMW 740i/L and 750i/L. Nowadays, all BMWs come with DSC III as standard including DTC (Dynamic Traction Control). The DTC allows more wheel slip meaning a more dynamic driving style with higher wheel traction including DSC controlling stability. In other words, the DTC will allow you to drive more aggressively without suiciding yourself.
The DSC system is very complex and interesting. It constantly checks vehicle speed, steering angle, wheel rotation, lateral and transverse acceleration, brake pressure and yaw to register imminent instability when cornering, especially on slippery conditions like snow and rain. When instability moment is registered, the DSC intervenes via the engine management system. It reduces drive torque and activates each wheel brake individually to keep the car stable. Everything this happens within milliseconds, so do not think you don't need this system.
So, the DSC uses ASC+T to cut the engine power and, if this is insufficient to maintain traction, it also uses ABS to apply braking power wherever it is needed.
The DSC uses a lot of sensors to work properly. First, it monitors the steering angle sensor to detect the driver's chosen path. After that it uses lateral- acceleration to define the forces, which must be transmitted to the road by the tires. The rate-of-turn sensor defines the car's degree of rotary movement and the brake-pressure sensor define the longitudinal forces acting between tires and road surface under braking.
If something went wrong while driving and the car begin to oversteer or to understeer, the DSC can counter the situation by applying brakes. All electronic and hydraulic systems are very rapid and precise, so the driver can hardly feel them.
- While ASC + T analyzes the longitudinal forces occurring in straight-ahead operation, DSC additionally registers and analyses lateral dynamic forces.
- When cornering at high speeds, DSC counters unstable vehicle states such as oversteering or understeering
- The DSC feature can provide maximum stability when cornering.
- With DSC there is a significant reduction in the risk of skidding.
The DTC (Dynamic Traction Control) is a sub-function of the DSC system. Besides offering sports-style driving, it provides a small amount of wheel spin improving traction, especially on deep snow, slush or loose terrain. In some occasions more slip generates better better traction and more thrust.
The DTC alloys sports-style driving and even permits controlled drifts. Still, the driver retains complete control over the vehicle in every situation and the Dynamic Stability Control's stabilising measures remain active even when the DTC is activated.
When you start the car and you are in normal driving mode, the DSC is active. One short push on the DSC button: the DTC is enabled and DSC restricted. One long push on the DSC button: DSC and DTC off.
So, we strongly do not recommend turning the Dynamic Traction Control off, because it is very dangerous.