This month – I’m explaining BMW’s active steering technology. While you will see many current car commercials from other manufacturers advertising “new” technology like blind spot detection, automatic emergency braking, and rear view cameras in 2017, the truth is BMW was often the originator of most of these technologies 10-15 years ago! BMW came out with Blind Spot Detection in 2009, Active Cruise Control (with emergency braking) around 2005, and rain/light sensors for automatic wipers in 1996. Yet BMW rarely advertises their innovative technology as much as they advertise the complete experience of driving a BMW. One such technology BMW has had since 2004 that makes for such an incredible driving experience is Active Steering.
Active Steering was standard on all 6 series and an option available on 3, 5 and X5 series in the mid 2000’s up. There are several main components of the system: Electrically variable motor integrated into the steering rack, Control Unit, Yaw Rate Sensor, Steering Angle Sensor, and the Electric Steering Cumulative Angle Sensor. The control unit also takes into consideration other vehicle inputs such as vehicle speed, and braking pressure. The most immediate difference that you will notice is an almost effortless power steering effort and less than 1 turn of the wheel each direction to reach the end stop. The steering feels extremely responsive and sharp at parking lot speeds. However, as vehicle speed increases, the steering loosens to avoid sharp panic maneuvers. Essentially, the steering wheel efforts varies based on road speed. Take into consideration the yaw rate sensor and the steering also is variable based on g forces in cornering for performance driving.
However, the most impressive feature of the system is its ability to autonomously take over steering in safety situations. The software of the Active Steering control unit has an extensive table of parameters programmed in so it essentially knows if you’re cruising at, say, 70 mph (x – vehicle speed) on the Interstate and make a panic fast steering move (y – steering angle sensor) to avoid an animal that would result in extreme oversteer (z – yaw rate sensor) and produce a dangerous yaw rate for that speed, It will over-ride your steering wheel input and use the electric motor in the steering rack to make only an appropiate amount of turning for you. This would prevent a dangerous yaw rate causing a spin out, all without you knowing. It can literally be the difference of preventing you from a spin or roll and you’ll never know it occurs aside from a blinking traction control light for a few seconds indicating the system is actively intervening. To determine if your BMW is equipped with active steering, turn the steering wheel from complete left to right lock – it should only take about 1 and 1/2 turns opposed to 2 1/2 to 3 with regular power steering.