Adaptive Cruise Control Acc

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

DESCRIPTION

The Adaptive Cruise Control (ACC) system interacts with the Lane Departure Warning (LDW) system to provide a complete system called Forward Collision Warning Plus (FCW+) which in the event of an imminent collision intervenes by automatically braking the vehicle to prevent the crash or mitigate its effects. A radar sensor mounted in the front area of the vehicle behind the front bumper detects objects on the trajectory of the vehicle. A video sensor, located in the windshield near the interior rear view mirror, measures the horizontal road signs and the position of the vehicle in relation to them.

The ACC system can only be set when the vehicle speed is between 30 and 160 km/h (20 and 100 mph)

The FCW + system can be deactivated (and then reactivated) via the specific setup menu in the Radio system. The LDW function only is switched OFF by pressing the button on the steering column stalk. If correctly turned on, the system will be activated whenever the engine is started.

The FCW+ only works if:

the vehicle speed is between 7 and 200 km/h (4 and 124 mph)
the front seat belts are fastened

A message appears on the display in case of conditions which limit system functionality (for example, fault, camera obstruction).

The radar sensor behind the bumper and the video sensor fitted on the windshield interpret and process all received inputs and if they indicate the risk of a collision sends messages to the other modules via the CAN data bus, in particular:

to the instrument panel which shows visual messages on the system state on the display
to the Body Control Module (BCM) which transmits sound warning requests on the sound system
to the brake control unit which applies the brakes to keep the set distance
to the engine control unit which adjusts the received torque

They are also connected to one another on a dedicated Private CAN data bus.

OPERATION

The radar sensor of the ACC system is powered by the INT circuit protected by a fuse in the BCM. It is connected to the other Controller Area Network (CAN) modules via two circuits, while two additional circuits are connected to a dedicated Private CAN of the Forward Facing Camera (FFC). The FFC receives an ignition-operated power supply (INT) circuit that is protected by a fuse in the BCM. The sensor is connected to each on pin 5.

The BCM receives direct battery power via a circuit protected by a maxi fuse in the maxi fuse box, located on the battery. The BCM receives an ignition-operated power supply (INT) circuit input by the signal coming from the Radio Frequency Hub (RFH) Module.

The Powertrain Control Module (PCM) is connected, via the CAN data bus, to the BCM and the Instrument Panel Cluster (IPC) to manage the visual messages indicating system state on the display. The control button for deactivating the Forward Collision Warning function on the Steering Column Control Module (SCCM) sends the OFF signal to the BCM.