Troubleshooting
Washer fluid level too low. Fill up the washer fluid reservoir as soon as possible ⇒ Washer
fluid.Fault in the rain/light sensor. Switch the ignition on and off. If the indicator lamp still lights
up permanently after you switch the ignition back on, seek expert assistance.Fault in
windscreen wipers. Switch the ignition on and off. If the indicator lamp still lights up permanently
after you switch the ignition back on, seek expert assistance.
Changes in the response of the rain/light sensor
Possible causes for faults and misinterpretations relating to the sensitive surface of the rain/light
sensor ⇒ Vehicle overviews include:
•Damaged wiper blades: a film of water or smears caused by damaged wiper blades can
increase the time the wipers are switched on, can shorten the length of the intervals between
wipes or cause the wipers to run quickly and continuously.
•Insects: insects hitting the windscreen surface can cause the wipers to be activated.
•Salt deposits: in winter, salt deposits on the windscreen can cause the wipers to continue to
wipe the windscreen when it is almost dry.
•Soiling: dry dust, wax, windscreen coatings (lotus effect), or detergent deposits (from an
automatic car wash) can cause the rain/light sensor to become less sensitive and react too
slowly, or prevent it from reacting at all. Clean the sensitive surface of the rain/light sensor
⇒ Caring for and cleaning the vehicle exterior at regular intervals and inspect the wiper blades
for damage.
•Crack in the windscreen: a wipe cycle will be triggered if the rain/light sensor is on when the
windscreen is impacted by a stone. The rain/light sensor will then register the reduction in
sensitivity of the surfaces and adjust accordingly. The size of the crack can affect the way in
which the rain/light sensor activates the wipers.
We recommend that you use an alcohol-based glass cleaner to remove wax and polish.
The wipers will try to wipe away any obstacles that are on the windscreen. The wipers will
stop moving if the obstacle blocks their path. Remove the obstacle and switch the wipers back on
again.
Mirrors
Introduction
This chapter contains information on the followingsubjects:
⇒ Interior mirror
⇒ Exterior mirrors
You can use the exterior mirrors and the interior mirror to observe traffic behind you and adjust
driving style accordingly.
For safety reasons it is important that the driver positions the exterior and interior mirrors correctly
before starting a journey ⇒.
Looking in the exterior mirrors and the interior mirror does not allow the driver to see the entire side
and rear area of the vehicle. The area that cannot be seen is known as the blind spot. There may
be objects and other road users in the blind spot.
Adjusting the exterior and interior mirrors while driving may cause the driver to become
distracted. This can lead to accidents and serious injuries.
•Exterior and interior mirrors should only be adjusted when the vehicle is stationary.
•When parking, changing lane, or performing an overtaking or turning manoeuvre,
always pay careful attention to the area around the vehicle as objects and other road
users may be located in the blind spot.
•Always ensure that the mirrors are positioned correctly and that the rear view is not
restricted by ice, snow, condensation or any other objects.
WARNING
If you estimate the distance from traffic behind you incorrectly, you can cause accidents
and serious injuries.
•Curved mirrors (convex or aspheric) enlarge the field of vision and can make objects in
the mirror seem smaller and further away than they actually are.
•Using curved mirrors to estimate the distance from other vehicles behind you when
changing lanes can provide inaccurate results and can lead to accidents and severe
injuries.
•Whenever possible, use the interior mirror to check the exact distance between your
vehicle and following traffic or other objects.
•Ensure that you have a good view to the rear of the vehicle.
WARNING
Interior mirror
Fig. 104 On the windscreen: automatic anti-dazzle interior mirror.
Fig. 105 On the windscreen: manual anti-dazzle interior mirror.
First read and observe the introductoryinformation and safety warnings⇒
Introduction
Automatic anti-dazzle interior mirror
When the ignition is turned on, the sensors measure the incident light from the rear ⇒ Fig. 104①
and from the front ②.
The interior mirror darkens automatically depending on the measured values.
If the incident light on the sensors is hindered or interrupted, e.g. by a sun blind or other hanging
objects, the automatic anti-dazzle interior mirror will not function or will not function correctly. Mobile
navigation devices attached to the windscreen or near the interior automatic anti-dazzle mirror can
also influence the sensors ⇒.
The automatic anti-dazzle function will be deactivated in some situations, e.g. when reverse gear is
engaged.
Automatic anti-dazzle mirrors contain an electrolyte fluid which could leak if the mirror is
broken.
•The leaking electrolyte fluid can cause irritation to the skin, eyes and respiratory
organs, especially in people who suffer from asthma or similar illnesses. Immediately
ensure that there is a sufficient supply of fresh air and get out of the vehicle. If this is
not possible, open all of the windows and doors.
•If the electrolyte fluid gets into the eyes or onto the skin, immediately wash the area
with plenty of water for at least 15 minutes and consult a doctor.
•If the electrolyte fluid gets onto shoes or clothing, wash immediately with plenty of
water for at least 15 minutes. Clean shoes and clothes thoroughly before wearing them
again.
•If the electrolyte fluid is swallowed, immediately rinse the mouth with plenty of water
for at least 15 minutes. Do not induce vomiting unless instructed to do so by a doctor.
Seek medical assistance immediately.
WARNING
If the glass of an automatic anti-dazzle mirror is broken, electrolyte fluid can leak from the
mirror. This fluid corrodes plastic surfaces. Remove the fluid as soon as possible, e.g.
using a wet sponge.
NOTICE
– Seat heating
Press the buttons or to switch the seat heating on and off ⇒ Seat heating.
If the function button is activated in the Infotainment system, it is not possible to
operate the rear controls.
Air recirculation mode
First read and observe the introductoryinformation and safety warnings⇒
Introduction
In air recirculation mode, no outside air enters the vehicle interior.
Manual air recirculation mode
•Press the button on the control panel to switch manual air recirculation mode on
and off.
Automatic air recirculation mode (Climatronic)
In automatic air recirculation mode, fresh air will enter the vehicle interior. The air recirculation
mode will switch on automatically if the system detects an increase in the concentration of noxious
substances in the outside air. The air recirculation mode will switch off as soon as the level of
noxious substances has returned to normal. The system cannot detect unpleasant odours.
•Press the button on the control panel.
•Touch function button .
•Touch the Automatic air recirculation function button.
Air recirculation mode with Air Care Climatronic
The vehicle is fitted with an allergen filter. When Air Care is activated ⇒ Air Care Climatronic, the
air recirculation mode of the air conditioning system is maximised as far as is permitted by the risk
of window fogging depending on the interior humidity and outside temperature. The air recirculation
mode is automatically regulated and features continuous adjustment in order to prevent fatigue of
the vehicle occupants.
When is the air recirculation mode deactivated?
Air recirculation mode is deactivated in the following situations ⇒:
•If the button on the Climatronic control panel is pressed.
•If the air distribution regulator of the manual air conditioning system is turned to position.
•If the sensor detects that the vehicle's windows might mist up.
When reversing the vehicle or when the wash and wipe system is being used, the air
recirculation mode will switch on to prevent odours from entering the vehicle interior.
•m/k/a999MK Climatronic
If the outside temperature is very high, brief activation of manual air recirculation mode helps
to cool the vehicle interior more quickly.
Seat heating
First read and observe the introductoryinformation and safety warnings⇒
Introduction
Stale air can quickly make the driver tired and affect their concentration, which in turn can
cause collisions, accidents and serious injuries.
•Never use the air recirculation mode for an extended period as no fresh air will enter
the vehicle interior.
•If the cooling system is switched off, the windows can mist up very quickly in air
recirculation mode and reduce visibility considerably.
•Switch off the air recirculation mode when it is no longer required.
WARNING
In vehicles with an air conditioning system, do not smoke when the air recirculation mode
is switched on. The smoke can leave a residue on the evaporator and the dust and pollen
filter with pollution filter insert, producing a lasting unpleasant odour.
NOTICE
•Touch the function button.
•Touch the Steering wheel & seat heating linked function button to pair the steering
wheel heating with the seat heating.
•Press the button to switch the steering wheel heating on or off with the seat heating.
Selecting a temperature setting (only in vehicles with Climatronic)
•Press the button on the control panel.
•Touch the function button.
•Touch the Setting function button to select a temperature setting.
Three temperature settings are available. The selected setting is saved when the ignition is
switched off. The temperature setting for the steering wheel heating is unrelated to the temperature
setting for the seat heating.
Switch-off conditions
The steering wheel heating will be switched off automatically if one of the following conditions is
met:
•Seat heating for the driver's seat switched off (if
Steering wheel & seat heating linked is active).
•Power consumption too high.
•Fault in steering wheel heating system.
Windscreen heating
First read and observe the introductoryinformation and safety warnings⇒
Introduction
The windscreen heating works when the engine is running.
Manual windscreen heating
•m/k/a995MKManual air conditioning system: press the button on the
Infotainment system and touch the Vehicle and Settings function buttons.
•m/k/a995MKClimatronic: press the button on the control panel.
•Touch the function button to switch windscreen heating on or off.
The windscreen heating switches itself off depending on the outside temperature or after 8 minutes
at the latest.
Automatic windscreen heating
The windscreen heating switches on automatically if there is a risk of condensation building up on
the windscreen or windows.
•Press the button on the control panel.
•Touch the function button in the Infotainment system.
•Touch the Automatic windscreen heating function button to switch automatic
windscreen heating on or off.
The automatic windscreen heating is also active when the air conditioning system is switched off.
Windscreen heating using the defrost function
The windscreen heating will be switched on when the defrost function is switched on and a sensor
detects that the windscreen may mist up.
Switch-off conditions
The windscreen heating switches itself off if one of the following conditions is met:
•Power consumption too high.
•Fault in air conditioning system.
•Specified time has elapsed.
Tips and usage notes
First read and observe the introductoryinformation and safety warnings⇒
Introduction
The following tips and operating information will help you use the system correctly.
Steering
Information on steering
The steering should be locked every time you leave the vehicle to make it more difficult for the
vehicle to be stolen.
Steering
The power steering is not hydraulic. It is an electromechanical system. The advantage of this
steering system is that no hydraulic hoses, hydraulic oil, pumps, filter or other parts are required.
The electromechanical system reduces fuel consumption. A hydraulic system requires constant oil
pressure in the system, whereas an electromechanical steering system only needs an energy
supply while steering.
In vehicles with driving profile selection, the selected driving profile can affect the behaviour of the
power steering ⇒ Driving profile selection and 4MOTION Active Control.
Electronic steering column lock in vehicles with starter button
The steering column will be locked if the driver door is opened and the ignition is switched off. For
this, the vehicle should be stationary and, if necessary, the gear selector lever should be in position
P.
If the ignition is not switched off until after the driver door is opened, the electronic steering column
will only be locked when the vehicle is locked using the vehicle key or the sensor in the door
handle.
Mechanical steering column lock (steering lock) in vehicles with an
ignition lock
The steering column is locked if the vehicle key is removed from the ignition lock when the vehicle
is stationary. Turn the steering wheel slightly until the steering lock clicks into place.
Insert the vehicle key into the ignition lock to unlock the steering lock. Turn the steering wheel
slightly to take the load off the steering lock mechanism. Hold the steering wheel in this position and
turn the ignition on.
Electromechanical steering
The power steering provided by the electromechanical steering system automatically adjusts to the
vehicle speed, steering wheel torque and steering wheel angle. The electromechanical steering
only functions when the engine is running.
You will need considerably more strength than normal to steer the vehicle if the power steering is
reduced or has failed completely.
Counter steering assistance
Counter steering assistance provides the driver with power steering in critical driving situations.
Additional steering power helps the driver when counter steering ⇒.
The intelligent Hill Descent Control technology cannot overcome the laws of physics, and
functions only within the limits of the system. Never allow the extra convenience afforded
by pull-away assist systems to tempt you into taking any risks when driving.
•Unintentional vehicle movements can cause serious injury.
•The Hill Descent Control cannot replace the full concentration of the driver.
•Always adapt your speed and driving style to suit visibility, weather, road and traffic
conditions.
•A Hill Descent Control System may not be able to always hold the vehicle on uphill
gradients or brake it sufficiently on all slopes going downhill (e.g. if the ground is
slippery or icy).
WARNING
Always be prepared to brake the vehicle. Accidents and injuries could occur if this is not
ensured.
•The Hill Descent Control system is only a support function and may not be able to
brake the vehicle sufficiently in all situations when driving downhill.
•The vehicle may accelerate despite the Hill Descent Control system.
WARNING
Speed range
ACC controls the vehicle in the speed range between 30 km/h (20 mph) and 160 km/h (100 mph)
or 210 km/h (130 mph). This speed range may differ in certain markets.
Radar sensor
ACC detects driving situations by means of the radar sensor at the front of the vehicle ⇒ Front
view. The range of the radar sensor is up to approximately 120 m.
Does the vehicle have ACC?
The vehicle is equipped with ACC if you can make settings for ACC in the vehicle settings of the
Infotainment system ⇒ Vehicle settings menu.
If the vehicle has ACC, the cruise control system is not available as an independent system.
Special driving situations
Fig. 142 On the instrument cluster display: slower vehicle detected in the left-hand lane
(illustration).
First read and observe the introductoryinformation and safety warnings⇒
Introduction
Overtaking
If you indicate left (left-hand traffic: indicate right) to overtake, ACC will accelerate the vehicle and
reduce the distance from the vehicle in front. Your set speed will not be exceeded.
If ACC does not detect any vehicle in front after you have changed lane, ACC will accelerate the
vehicle up to the set speed.
Stop-and-go traffic
ACC can brake vehicles with DSG dual clutch gearbox to a standstill and hold them stationary.
ACC remains active and the instrument cluster display shows ACC ready for a few seconds.
During this time the vehicle will move off again automatically as soon as the vehicle in front moves
off (depending on the vehicle equipment level and not available in all countries).
•Press the button.
•Press the button or briefly press the accelerator.
The intelligent technology used in the ACC cannot overcome the laws of physics, and
functions only within the limits of the system. Never let the extra convenience tempt you
into taking safety risks when driving. Careless or unintentional use of the Adaptive Cruise
Control (ACC) can cause accidents and lead to serious injury. The system is not a
substitute for the full concentration of the driver.
•Adapt your speed and distance from the vehicles ahead to suit visibility, weather, road
and traffic conditions.
•Do not use the ACC in poor visibility, on steep or winding roads, on slippery road
surfaces, e.g. on snow, ice, wet roads, loose chippings, or on flooded roads.
•Never use ACC off-road or on non-surfaced roads. The ACC is designed for use on
surfaced roads only.
•ACC does not respond to stationary vehicles.
•The ACC does not react to persons, animals or vehicles crossing or approaching in the
same lane.
•Brake immediately if speed reduction by ACC is not sufficient.
•Brake immediately if a request to brake appears on the instrument cluster display.
•Brake if the vehicle starts rolling unintentionally after a request to brake.
•Be prepared to control the speed yourself at all times.
WARNING
®
•The vehicle is stationary for longer than approximately three minutes.
•A vehicle door is opened.
•The ignition is switched off.
Avoiding overtaking on the right (left-hand traffic: overtaking on the left)
If ACC detects a slower vehicle in the left-hand lane (left-hand traffic: in the right-hand lane), ACC
will brake the vehicle gently within the system limits and therefore prevent a prohibited overtaking
manoeuvre ⇒ Fig. 142. The function is active from speeds of around 80 km/h (50 mph), but is not
available in all countries.
System limits
Fig. 143 Driving through bends. Vehicles outside the range of the radar sensor.
Fig. 144 Vehicle changes lane. Turning vehicle and stationary vehicle.
First read and observe the introductoryinformation and safety warnings⇒
Introduction
When not to use ACC
•Driving in heavy rain, snow or heavy spray
•Driving through tunnels
•Driving through road works
•Driving on twisting roads, e.g. mountain roads
•Driving off-road
•Driving in multi-storey car parks
•Driving on roads with embedded metal objects, e.g. railways tracks
•Driving on roads with loose chippings
•m/k/a995MK Vehicles without inside overtaking prevention function: driving on multi-lane
roads when vehicles in the overtaking lane are driving more slowly.
Objects that cannot be detected
•Persons
•Animals
•Stationary vehicles
•Crossing or oncoming vehicles
•Other stationary obstacles
If the message ACC ready is shown on the instrument cluster display and the vehicle in
front moves off, your vehicle will move off automatically. In some cases, the radar sensor
may be unable to detect obstacles that are located in the vehicle's path. This can result in
serious injury and accidents.
•Always check the road ahead before moving off and brake the vehicle if necessary.
WARNING
If a stationary vehicle is hidden behind a vehicle that has been detected by the adaptive cruise
control and this vehicle turns off the road or changes lane, the ACC will not react to the stationary
vehicle ⇒ Fig. 144.
Bends
The radar sensor always measures straight ahead. For this reason, vehicles may be incorrectly
detected or vehicles driving ahead not detected in tight bends ⇒ Fig. 143.
Vehicles outside the sensor range
•Vehicles that are driving outside the sensor range in close proximity to your vehicle, e.g.
motorbikes ⇒ Fig. 143.
•Vehicles that change into your lane directly in front of your vehicle ⇒ Fig. 144.
•Vehicles with bodies or attachments that project beyond the vehicle.
Switching ACC on and off
Fig. 145 Left-hand side of the multifunction steering wheel: buttons for operating ACC
First read and observe the introductoryinformation and safety warnings⇒
Introduction
Switching on ACC
•Press the button.
The indicator lamp lights up grey, ACC does not regulate.
Starting control
•Press the button while driving forwards.
ACC stores the current speed and maintains the set distance. If the current speed is outside the
defined speed range, ACC will set the minimum speed (when driving more slowly than the limit) or
maximum speed (when driving faster than the limit).
The following indicator lamps light up, depending on the driving situation:
ACC regulating.No vehicle has been detected ahead.Vehicle detected ahead (white).
Interrupting control
•Briefly press the button or press the brake pedal.
The indicator lamp lights up grey, the speed and distance remain stored.
Control is automatically interrupted if the traction control system (TCS) is deactivated.
Resuming control
•Press the button.
ACC adopts the last set speed and last set distance. The instrument cluster display shows the set
speed and the indicator lamp lights up green.
Switching off ACC
•Press and hold the button.
The set speed is deleted.
Changing to the speed limiter
If you use ACC in the above situations, this can result in accidents and serious injuries as
well as violation of legal regulations.
WARNING