Adjustable rate shock absorbers provide a means of changing their rate of dampening of the spring oscillations, to suit road conditions. Electronic controls let the changes occur either automatically, or as the driver prefers.
Each shock absorber has a rotary solenoid that can alter the dampening rate by changing the number of restrictions the oil must pass through.
In this position, all orifices are open. Oil can flow more easily through the passageways in the piston. Only a small dampening effect is applied to the oil.
This provides a dampening force that emphasizes ride comfort when traveling at low speeds.
Closing some orifices makes it harder for fluid to flow through the piston. This increases the dampening effect of the shock absorber, providing a firmer ride, more suitable for higher speeds, and faster cornering.
The solenoid is operated by an electrical signal from the electronic control unit, or ECU.
The ECU allows different modes of operation, according to a selector switch on the dash-board. In the Auto position, the dampening effect at the front wheels is increased at road speeds above 80 kilometers per hour.
This improves vehicle stability at high speeds. The rear shock absorbers stay at their normal setting.
The Manual position has two settings - Normal or Sport. In Normal setting, all shock absorbers remain at a rate suited to ride comfort. There is no change to the settings at high speeds.
The Sport setting increases the dampening rate of all the shock absorbers. This is more suited to brisk driving, with heavy acceleration and cornering.
