Active Brake Assist (ABA)

p4 dm 05.02.000

Overview

Active Brake Assist is always on, automatically tracking the distance from the front of the tractor to other vehicles in its path using bumper-mounted radar.

The radar tracks stationary objects in the vehicle's path and has the capacity to engage full braking on these objects, such as a parked vehicle or stopped traffic.

The radar system can detect most pedestrians moving within the vehicle’s path as long as they stay in motion; the system can act to help mitigate a collision at vehicle speeds below 25mph (40 km/h). If the system detects a pedestrian in motion within the radar system’s parameters for potential danger, the vehicle will give a visual and auditory warning, and, if the driver doesn't respond, engage in partial braking.

The radar may not detect pedestrians in every possible situation, nor is it a substitute for cautious driving.

Safety Information

Warning: Active Brake Assist (ABA) is intended only as an aid for a conscientious and alert driver. The driver is responsible for keeping a safe distance from the vehicle in front, for the vehicle speed, braking in good time, and remaining in lane.

ABA does not take road and weather conditions into account, nor the prevailing traffic situation. The driver should always adapt driving style to suit prevailing road and weather conditions.

ABA is not a substitute for safe driving procedures.

Operate a vehicle equipped with Detroit Assurance Collision Mitigation System as if the vehicle were not equipped with a collision mitigation system.

The Detroit Assurance Collision Mitigation System will not warn of hazards such as animals, oncoming vehicles, or cross traffic.

Failure to drive safely and use the system properly could result in personal injury and/or death and severe property damage.

If your vehicle is equipped with ABA, it can (within system limitations):

react more quickly to an object in your path of travel;
perform emergency braking; and
react to moving people with a warning and partial braking.

Active brake assist can minimize the risk of a front-end collision with a moving or stationary vehicle. If ABA detects the risk of a front-end collision, it issues an audible and visual warning. If the risk persists, ABA automatically initiates partial braking of the vehicle. If the driver does not react to the warnings and partial brake application, ABA automatically initiates a full brake application.

Active brake assist may detect moving people within the vehicle's path and along the edge of the lane and can act to help mitigate a collision at speeds below 25mph (40 km/h).

Active brake assist may not detect narrow vehicles, like motorcycle, driving in front, or vehicles driving on a different lane.

Active brake assist does not automatically adapt to road and traffic conditions. Brake the vehicle using the service brake if:

an event window with the warning symbol appears on the driver display screen;
an intermittent warning tone sounds; or
an intermittent warning tone sounds and automatic partial braking was initiated.

If no visual and/or acoustic warning is issued in a critical situation:

Active brake assist has not recognized the danger of the situation; or
Active brake assist is suppressed; or
Active brake assist has failed.

Active brake assist-triggered emergency braking can be deactivated if the driver presses the accelerator pedal beyond the pressure point (kickdown).

Important: If there is risk of a collision, adaptive cruise control (ACC) may warn the driver before active brake assist (ABA).

Collision Warning and Emergency Braking

If there is a risk of collision, ABA issues alerts on the driver display, sounds an audible warning, and illuminates the ABA indicator lamp on the dash. See Fig.. In addition, the radio and/or hands-free systems like Detroit Connect are muted. The ABA series of warnings is as follows:

Warning (ABA): An alert appears on the driver display and an intermittent warning tone sounds.
Partial Braking (ABA): If the driver does not respond, the system pulses the brakes while presenting a visual alert on the dash and sounding a solid warning tone. At this point ABA brakes the vehicle with around 50% of the vehicle's maximum braking power.
Emergency braking (ABA): If the driver does not react to the collision warnings or partial brake application, ABA automatically initiates emergency braking (full brake application). The warning message appears on the driver display, and a continuous warning tone sounds.

Fig. 1, ABA Indicator Lamp

Caution: After emergency braking, the vehicle is held by the service brake for up to 5 seconds to prevent it from rolling away.

After an emergency braking maneuver has been performed, retake control of the vehicle as soon as possible and, paying attention to the traffic situation, remove the vehicle from the area of danger. Stop the engine and apply the parking brake. Inspect the vehicle to ensure it is in proper operating order and confirm the load is secured before resuming driving.

Always apply the parking brake upon shutting the engine off or prior to exiting the vehicle.

The driver can interrupt emergency braking by pressing the accelerator pedal beyond the point of resistance (kickdown).

Driving Situations

See Table for a description of adaptive cruise control and active brake assist limitations in specific driving conditions.

Table 1, Active Brake Assist Limitations

Active Brake Assist Limitations
Condition	Visual	Description
Cornering, entering and exiting bends		The ability of ABA and ACC to detect vehicles on bends is limited. ABA and ACC may unexpectedly issue warnings or brake the vehicle. ACC may also accelerate the vehicle unexpectedly.
Driving in a different lane, and stationary vehicles		The ability of ABA and ACC to detect vehicles driving in a different lane is limited. ABA and ACC may unexpectedly issue warnings or brake the vehicle. ACC may also accelerate the vehicle unexpectedly. With Active Brake Assist 4.0, the radar tracks stationary objects and has the capacity to engage full braking on these objects, such as a parked vehicle or stopped traffic in the vehicle’s path.
Other vehicles changing lane		The ability of ABA and ACC to detect vehicles pulling into your lane without maintaining a safe distance is limited. The distance to the vehicle in front entering your lane may be too short. ABA may unexpectedly issue warnings or brake the vehicle.
Other vehicles changing lane		The ability of ABA and ACC to detect vehicles pulling into your lane without maintaining a safe distance is limited. They do not detect vehicles until they are within the radar's detection range. If the vehicle is too narrow, ACC may accelerate unexpectedly. Brake the vehicle to increase the distance to the vehicle in front.
Vehicles turning off		The ability of ABA and ACC to detect vehicles turning off is limited. ABA and ACC may unexpectedly issue warnings or brake your vehicle.
Overtaking		When passing, ABA and ACC may unexpectedly issue warnings or brake your vehicle if your vehicle is too close to the vehicle in front and is in the same lane.
Winding stretches of road		On winding stretches of road, ABA and ACC cannot detect which lane the vehicle in front is driving in. ABA and ACC may unexpectedly issue warnings or brake your vehicle. ACC may also accelerate the vehicle unexpectedly.
Obstacles and stationary vehicles in front of the tracked vehicle		ABA and ACC cannot detect obstacles or stationary vehicles in front of the detected vehicle. ABA and ACC may unexpectedly issue warnings or brake your vehicle. ACC may also accelerate the vehicle unexpectedly.
Stationary objects		ABA may unexpectedly issue warnings and brake the vehicle if it detects stationary objects like: vehicles which have broken down parked or stopped vehicles signs bridges
Stationary people		ABA can react incorrectly to the following conditions: stationary people people or objects that quickly enter the field of detection of the sensor people in a tunnel ABA can also react unexpectedly to people who are standing on the roadside in a curve.