Pre-Collision Assist System Operation

WARNING: This page is about a different car, the 2018 Lincoln Continental. However, it is still accessible from the selected car via links, so may be relevant.

The pre-collision assist system is an additional safety feature on vehicles equipped with adaptive cruise control. The system is active whether the adaptive cruise control system is on or off. If the system detects a vehicle, pedestrian or other object in the vehicle path of travel, the system provides three levels of functionality:

Visual and audible alert
Brake support
Active braking

The system uses object detection information from the radar sensor integrated in the CCM and the forward-looking camera in the IPMA mounted in the interior rear view mirror. The CCM and the IPMA scan a designated area in front of the vehicle. Messages are sent between the CCM and the IPMA on dedicated CAN circuits, which determine whether an object, vehicle or pedestrian is in the path of travel, the approximate distance to the object and how fast the vehicle is approaching it.

When the vehicle approaches the object, the CCM sends a message to the HUD module on the HS-CAN2 (LED display HUD) to flash the red warning Light Emitting Diodes (LEDs) or sends a message through the GWM to the HS-CAN3 (driver information display HUD) to show a solid red bar display. The CCM sends an alert message on the HS-CAN2 to the GWM, and then to the IPC on the HS-CAN3 to sound an audible alert and show a warning message in the message center display. The CCM also sends a message to the ABS module on the HS-CAN2 to pre-charge the brakes in order to prepare them for rapid braking by the driver. If the system determines that a collision is imminent, an active braking message is sent from the CCM to the ABS module. The system will reduce the gap between the brake pads and discs, applying the brakes to slow vehicle speed without driver intervention. The vehicle will stop the vehicle to help the driver avoid a collision or reduce damage caused by the impact.

The pre-collision alert system uses image recognition software that can differentiate between shapes, which allows the system to determine if the approaching object is a vehicle or a pedestrian. If the camera does not recognize the shape as the rear end of a vehicle or a pedestrian, the system will not provide full function. The system may not work properly at night, in direct or low sunlight, when camera vision is reduced due to weather conditions or due to a blocked CCM radar sensor. If the IPMA camera module is obstructed, the pre-collision system will not respond properly to pedestrians or stationary vehicles, and reduces the ability to recognize moving vehicles. Unconventional vehicle types, pedestrians in groups or with complex backgrounds, or partly obscured pedestrians also may not be properly detected by the system.

The pre-collision assist system is active at speeds above 5 km/h (3 mph) and pedestrian detection is active at speeds up to 80 km/h (50 mph).

The pre-collision assist system has three levels of sensitivity detection (HIGH, NORMAL and LOW) that can be changed through the message center display in the IPC. The alert sensitivity can be adjusted and active braking can be turned OFF in the IPC. The active braking function will revert back to ON at the next ignition cycle.

When a system fault is detected with the forward collision warning system, the message PRE-COLLISION ASSIST NOT AVAILABLE SENSOR BLOCKED or PRE-COLLISION ASSIST NOT AVAILABLE is displayed in the IPC message center.