Pre-Collision Assist System Operation

WARNING: This page is about a different car, the 2020 Ford F-150. However, it is still accessible from the selected car via links, so may be relevant.

The pre-collision assist system is offered as a camera-only option without ACC. An additional safety feature on vehicles equipped with ACC uses both the CCM and the IPMA. The system is active whether the ACC 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

Vehicles equipped with ACC 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. Network 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.

Vehicles equipped without ACC uses object detection information from the forward-looking camera in the IPMA only.

When the vehicle approaches the object, the IPMA sends a message to the HUD module (if equipped) on the HS-CAN2 to flash the red warning Light Emitting Diodes (LEDs). If the vehicle is not equipped with a HUD module the IPMA sends a message through the GWM on the HS-CAN3 to the IPC message center. The IPC sends a message on the HS-CAN3 to the ACM to sound an audible alert. The IPMA 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 IPMA to the ABS module. The system reduces the gap between the brake pads and discs, applying the brakes to slow vehicle speed without driver intervention. This assists stopping 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 does 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 does 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 may not be properly detected by the system.

The pre-collision assist system is active at speeds above 5 kmh (3 mph) and pedestrian detection is active at speeds up to 80 kmh (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 reverts back to on at the next ignition cycle.

When a system fault is detected with the pre-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.