Mercedes-Benz GLC : Driving and driving safety systems / Active Brake Assist

Function of Active Brake Assist

Active Brake Assist consists of the following functions:

• Distance warning function
• Autonomous braking function
• Situation-dependent braking assistance
• Vehicles with Driving Assistance Package: Evasive Steering Assist and cornering function

Active Brake Assist can help you to minimize the risk of a collision with vehicles, cyclists or pedestrians or to reduce the effects of such a collision.

If Active Brake Assist has detected a risk of collision, a warning tone sounds and the distance warning lamp lights up in the instrument cluster.

If you do not react to the warning, autonomous braking can be initiated in critical situations.

In especially critical situations, Active Brake Assist can initiate autonomous braking directly.

In this case, the warning lamp and warning tone occur simultaneously with the braking application.

If you apply the brake yourself in a critical situation or apply the brake during autonomous braking, situation-dependent braking assistance occurs. The brake pressure increases up to maximum full-stop braking if necessary.

Observe the notes on driving systems and your responsibility; you may otherwise fail to recognize dangers.

If autonomous braking or situation-dependent braking assistance has occurred, display appears in the multifunction display and then automatically goes out after a short time.

WARNING Risk of an accident caused by limited detection performance of Active Brake Assist

Active Brake Assist cannot always clearly identify objects and complex traffic situations.

Active Brake Assist is only an aid. The driver is responsible for maintaining a sufficiently safe distance to the vehicle in front, vehicle speed and for braking in good time.

Always pay careful attention to the traffic situation; do not rely on Active Brake Assist alone.

Be prepared to brake or swerve if necessary.

Also observe the system limits of Active Brake Assist.

The individual subfunctions are available in various speed ranges:

The distance warning function can issue a warning in the following situations:

From approximately 4 mph (7 km/h), if your vehicle is critically close to a vehicle, cyclist or pedestrian, you will hear an intermittent warning tone and the distance warning lamp lights up in the instrument cluster.

Brake immediately or take evasive action, provided it is safe to do so and the traffic situation allows this.

Distance warning function (vehicles without Driving Assistance Package)

The distance warning function can aid you in the following situations with an intermittent warning tone and a warning lamp:

• at speeds up to approximately 155 mph (250 km/h) when approaching vehicles ahead
• at speeds up to approximately 50 mph (80 km/h) when approaching stationary vehicles, moving pedestrians and cyclists ahead
• at speeds up to approximately 37 mph (60 km/h) when approaching crossing cyclists

Distance warning function (vehicles with Driving Assistance Package)

The distance warning function can aid you in the following situations with an intermittent warning tone and a warning lamp:

• at speeds up to approximately 155 mph (250 km/h) when approaching vehicles ahead
• at speeds up to approximately 62 mph (100 km/h) when approaching stationary vehicles
• at speeds up to approximately 50 mph (80 km/h) when approaching moving pedestrians and cyclists ahead
• at speeds up to approximately 43 mph (70 km/h) when approaching stationary pedestrians, crossing vehicles and stationary and crossing cyclists

Autonomous braking function (vehicles without Driving Assistance Package)

If the vehicle is traveling at speeds above approximately 4 mph (7 km/h), the autonomous braking function may intervene in the following situations:

• at speeds up to approximately 124 mph (200 km/h) when approaching vehicles ahead
• at speeds up to approximately 50 mph (80 km/h) when approaching cyclists ahead
• at speeds up to approximately 37 mph (60 km/h) when approaching moving pedestrians and crossing cyclists
• at speeds up to approximately 31 mph (50 km/h) when approaching stationary vehicles

Autonomous braking function (vehicles with Driving Assistance Package)

If the vehicle is traveling at speeds above approximately 4 mph (7 km/h), the autonomous braking function may intervene in the following situations:

• at speeds up to approximately 155 mph (250 km/h) when approaching vehicles ahead
• at speeds up to approximately 62 mph (100 km/h) when approaching stationary vehicles
• at speeds up to approximately 50 mph (80 km/h) when approaching cyclists ahead
• at speeds up to approximately 43 mph (70 km/h) when approaching stationary and moving pedestrians, crossing vehicles and stationary and crossing cyclists

Situation-dependent braking assistance (vehicles without Driving Assistance Package)

• The situation-dependent braking assistance can intervene from a speed of approximately 4 mph (7 km/h) in the following situations:
• at speeds up to approximately 155 mph (250 km/h) when approaching vehicles ahead
• at speeds up to approximately 50 mph (80 km/h) when approaching stationary vehicles and vehicles ahead
• at speeds up to approximately 37 mph (60 km/h) when approaching moving pedestrians and crossing cyclists

Situation-dependent braking assistance (vehicles with Driving Assistance Package)

The situation-dependent braking assistance can intervene from a speed of approximately 4 mph (7 km/h) in the following situations:

• at speeds up to approximately 155 mph (250 km/h) when approaching vehicles ahead
• at speeds up to approximately 62 mph (100 km/h) when approaching stationary vehicles
• at speeds up to approximately 50 mph (80 km/h) when approaching cyclists ahead
• at speeds up to approximately 37 mph (60 km/h) when approaching stationary and moving pedestrians, crossing vehicles and stationary and crossing cyclists

Canceling a brake application of Active Brake Assist

You can cancel a brake application of Active Brake Assist at any time by:

• sharply depressing the accelerator pedal or with kickdown
• releasing the brake pedal

Active Brake Assist may cancel the brake application when one of the following conditions is fulfilled:

• You maneuver to avoid the obstacle.
• There is no longer a risk of collision.
• An obstacle is no longer detected in front of your vehicle.

Evasive Steering Assist (only vehicles with Driving Assistance Package)

Evasive Steering Assist has the following characteristics:

• The ability to detect stationary or moving pedestrians.
• Assistance through power-assisted steering if it detects a swerving maneuver.
• Activation by an abrupt steering movement during a swerving maneuver.
• Assistance during swerving and straightening of the vehicle.
• Reaction from a speed of approximately 12 mph (20 km/h) up to a speed of approximately 43 mph (70 km/h).

You can prevent the assistance at any time by actively steering.

Cornering function (only vehicles with Driving Assistance Package)

If a danger of collision from an oncoming vehicle is detected when turning across an oncoming lane, autonomous braking can be initiated at speeds below 9 mph (15 km/h) before you have left the lane in which you are driving.

WARNING Risk of accident despite Evasive Steering Assist

Evasive Steering Assist cannot always recognize objects or complex traffic situations clearly.

Moreover, the steering support provided by Evasive Steering Assist is not sufficient to avoid a collision.

Always pay careful attention to the traffic situation; do not rely on Evasive Steering Assist alone.

Be prepared to brake or swerve if necessary.

End the support by actively steering in non-critical situations.

Drive at an appropriate speed if there are pedestrians close to the path of your vehicle.

System limits

Full system performance is not available for a few seconds after switching on the ignition or after driving off.

If Active Brake Assist is impaired or inoperative due to a malfunction, the warning lamp appears in the multifunction display.

The system may be impaired or may not function, particularly in the following situations:

• In snow, rain, fog, heavy spray, if there is glare, in direct sunlight or in greatly varying ambient light.
• If the sensors are dirty, fogged up, damaged or covered.
• If the sensors are impaired due to interference from other radar sources, e.g. strong radar reflections in parking garages.
• If a loss of tire pressure or a faulty tire has been detected and displayed.
• If DSR is active.
• In complex traffic situations where objects cannot always be clearly identified.
• If pedestrians or vehicles move quickly into the sensor detection range.
• If pedestrians are hidden by other objects.
• If the typical outline of a pedestrian cannot be distinguished from the background.
• If a pedestrian is not detected as such, e.g. due to special clothing or other objects.
• If the driver's seat belt is not fastened.
• On curves with a tight radius.

The Active Brake Assist sensors adjust automatically while a certain distance is being driven after the vehicle has been delivered. Active Brake Assist is unavailable or only partially available during the teach-in process.