Important safety notes

Active Lane Keeping Assist monitors the area in front of your vehicle by means of a camera at the top of the windshield. Active Lane Keeping Assist detects lane markings on the road and warns you before you leave your lane unintentionally. If you do not react to the warning, a lane-correcting application of the brakes can bring the vehicle back into the original lane.

1 Active Lane Keeping Assist camera

If you have selected the Display Unit Speed-/Odometer(Y page 233) function in the on-board computer and select km as the unit of measurement, Active Lane Keeping Assist is active from speeds of 60 km/h. If the miles display unit is selected, the assistance range begins at 40 mph.

WARNING
Active Lane Keeping Assist does not keep your vehicle in its lane. It is only an aid and may detect the lane markings on the road incorrectly or not at all.
The system may be impaired or may not function if:
- several or no lane markings for a single lane are present.
- there is poor visibility, e.g. due to insufficient illumination of the road, or due to snow, rain, fog or spray.
- there is glare, e.g. from oncoming traffic, the sun, or reflection from other vehicles.
- the windshield is dirty, fogged up or covered, for instance by a sticker, in the vicinity of the camera.
- the lane markings are worn away, dark or covered up, e.g. by dirt or snow.
- the distance to the vehicle in front is too small and the lane markings thus cannot be detected.
- the lane markings on the road are unclear, e.g. near roadworks.
- the lane markings change quickly, e.g. lanes branch off, cross one another or merge.
- the road is narrow and winding.
Active Lane Keeping Assist cannot detect road and traffic conditions. It is not a substitute for attentive driving. You are responsible for the vehicle's speed, braking in good time, and steering correctly. Always adapt your driving style to suit the prevailing road and weather conditions. Always pay attention to traffic conditions and your surroundings. Otherwise, you may fail to recognize dangers in time, cause an accident and injure yourself and others.

Warning vibration in the steering wheel

A warning can be given when a front wheel passes over a lane marking. You will be warned by means of intermittent vibration in the steering wheel for up to 1.5 seconds.

In order that you are warned only when necessary and in good time if you cross the lane marking, the system recognizes certain conditions and warns you accordingly.

The warning vibration occurs earlier if:
- you approach the outer lane marking on a bend.
- the road has very wide lanes, e.g. a freeway.
- the system recognizes solid lane markings.

The warning vibration occurs later if:
- the road has narrow lanes.
- you cut the corner on a bend.

Lane-correcting brake application

If you leave your lane under certain circumstances the vehicle will brake briefly on one side. This is meant to assist you in bringing the vehicle back to the original lane.

This function is available in the range between 40 mph and 120 mph (60 km/h to 200 km/h).

A lane-correcting brake application can only be made after driving over a solid, recognizable lane marking. Before this, a warning must be given by means of intermittent vibration in the steering wheel.

In addition, a lane with lane markings on both sides must be recognized. The brake application also slightly reduces vehicle speed.

If a lane-correcting brake application occurs, the following, for example, appears in the multifunction display:

A further lane-correcting brake application can only occur after your vehicle has returned to the original lane.

WARNING
Active Lane Keeping Assist does not keep your vehicle in its lane. It is only an aid designed to assist driving. It is not a substitute for attentive driving. In some cases, the lanecorrecting brake application is not sufficient to bring your vehicle back to the original lane.
In such cases, you must steer the vehicle yourself to ensure that it does not leave the lane.
Active Lane Keeping Assist does not detect road and traffic conditions. Always make sure that there is sufficient distance to the side for other traffic or obstacles. In rare cases, unclear markings or particular structures on the roadway can be recognized as solid lane markings. An inappropriate brake application, e.g. after intentionally driving over a solid lane marking, may be interrupted at any time by steering slightly in the opposite direction.
Active Lane Keeping Assist cannot take weather conditions into account.
You are responsible for the driving at appropriate speeds, braking in good time, and steering correctly. Always adapt your driving style to suit the prevailing road and weather conditions. Always pay attention to traffic conditions and your surroundings. Otherwise, you may fail to recognize dangers in time, cause an accident and injure yourself and others.

No lane-correcting brake application occurs if:
- you clearly and actively steer, brake or accelerate.
- you cut the corner on a sharp bend.
- you switch on the turn signals.
- a driving safety system intervenes, e.g. ESP®, PRE-SAFE® Brake or Active Blind Spot Assist.
- you have adopted a sporty driving style with high cornering speeds or high rates of acceleration.
- on vehicles with a trailer tow hitch, the electrical connection to the trailer has been correctly established.
- ESP® is switched off.
- the transmission is not in position D.
- the off-road program is switched on.
- a loss of tire pressure or a defective tire has been detected and displayed.

Active Lane Keeping Assist does not detect traffic situations or road users. An inappropriate brake application may be interrupted at any time if you:
- steer slightly in the opposite direction.
- use a turn signal.
- clearly brake or accelerate.

A lane-correcting brake application is interrupted automatically if:
- a driving safety system intervenes, e.g. ESP®, PRE-SAFE® Brake or Active Blind Spot Assist.
- lane markings can no longer be recognized.

Switching on Active Lane Keeping Assist

– Switch on Active Lane Keeping Assist using the on-board computer; to do so, select Standard or Adaptive(Y page 233).
Symbol 1 appears in the multifunction display.
If Standard is selected, no warning vibration occurs if:
- you switch on the turn signals. In this event, the warnings are suppressed for a certain period of time.
- a driving safety system intervenes, such as ABS, BAS or ESP®.
If Adaptive is selected, no warning vibration occurs if:
- you switch on the turn signals. In this event, the warnings are suppressed for a certain period of time.
- a driving safety system intervenes, e.g. ABS, BAS or ESP®.
- you accelerate hard, e.g. kickdown.
- you brake hard.
- you steer actively, e.g. swerve to avoid an obstacle or change lane quickly.
- you cut the corner on a sharp bend.

Trailer towing

When you attach a trailer, make sure you have correctly established the electrical connection. This can be accomplished by checking the trailer lighting.