The trailer stabilisation control in the BMW X3 and X5 is an innovative safety system that recognises the presence of a trailer as soon as the trailer plug is inserted into the power socket at the rear. This activates the system, which can intervene in the vehicle's motion once a speed of 65 km/h or more is reached. The trailer stability control is integrated in the Dynamic Stability Control (DSC) and uses DSC sensors to monitor the yaw rate (rotation around the vertical axis) of the vehicle.
If the sensors identify behaviour that is typically associated with a swaying motion, the engine output is cut and all four wheels are braked automatically. The trailer's motion soon returns to normal thanks to the system's fast response. By taking control of the vehicle's speed, the system provides additional safety in potentially dangerous situations and when directional stability is impaired.