The system warns the driver of potential hazards by providing three levels of assistance.
Collision Alert
If your vehicle is rapidly approaching potential hazards the system provides the following levels of functionality:
  1. Alert.
  1. Brake support.
  1. Automatic emergency braking.
Forward Collision Warning ON  Alert: When active, a flashing visual warning appears and an audible warning tone sounds.
Brake Support: The system helps reduce the impact speed by preparing the brakes for rapid braking. The system does not automatically apply the brakes. If you press the brake pedal, the system may apply additional braking up to maximum braking force, even if you lightly press the brake pedal.
Automatic Emergency Braking: Automatic emergency braking may activate if the system determines that a collision is imminent.
Note:   If the pre-collision assist alerts are too frequent or disturbing, you can reduce the alert sensitivity. Setting the low sensitivity results in fewer and later warnings of a potential forward collision. The manufacturer recommends using the high sensitivity setting where possible.
Note:   Automatic emergency braking performance is not affected by the sensitivity setting.
Each system has various levels of detection capabilities.   See   Pre-Collision Assist Limitations