What is an Active Suspension System Height Sensor?
Active suspension systems on modern vehicles use hydraulic or pneumatic pressure to change the ride height, dampening characteristics, and rigidity of the suspension according the the road surface any precise moment. They will typically use a pump or compressor to send pressurized fluid or air to the suspension on each corner of the vehicle, which will raise or lower the vehicle, or increase and decrease stiffness. In order to control this action, a central computer, the active suspension system control module, will use feedback from pressure sensors, yaw sensors, and ride height sensors to determine when and how the vehicle should react. The height sensor is perhaps the most crucial sensor in the active suspension system due the high congruence of information it provides.
How do Active Suspension System Height Sensors work?
As the vehicle goes down the road, turns, parks, accelerates, or slows, the height sensors on each corner of the vehicle are always measuring the ride height of each corner. This information is relayed to the active suspension system control module at a rate of over 100 times per second in many systems. Since these sensors are monitoring all four corners of the vehicle, the control module can easily compare the ride height information for each wheel, and use air pressure or relief to adjust the suspension settings to provide an appropriate and desirable driving experience.
What are the symptoms of a bad Active Suspension System Height Sensor?
A failed or failing height sensor will alert the driver in one of two ways. Either the sensor will allow one corner of the vehicle to sit much higher or lower than the other corners of the vehicle, or a warning light related to the active suspension system will illuminate. In the event that the ride height is affected, it may not be evident there is an issue at all. If the vehicle is typically driven and parked on smooth, flat surfaces, the suspension may only call for minute adjustments that the driver never notices. However, if the vehicle is parked on a hill, the driver may notice the vehicle inexplicably sitting in a very awkward angle. This would be due to the fact that one corner of the vehicle would either adjust at a much different rate, or not adjust at all.