check engine light MERCEDES-BENZ C CLASS 2018 User Guide

When you take advantage of engine braking, a
drive wheel may not turn for some time, e.g.
on a slippery road surface. This could cause
damage to the drive train. This type of damage is not covered by the Mercedes-Benz war-
ranty.
Heavy and light loads
GWARNING
If you rest your foot on the brake pedal while
driving, the braking system can overheat. This increases the stopping distance and can even
cause the braking system to fail. There is a
risk of an accident.
Never use the brake pedal as a footrest. Never
depress the brake pedal and the accelerator
pedal at the same time.
!Depressing the brake pedal constantly
results in excessive and premature wear to
the brake pads.
If the brakes have been subjected to a heavy
load, do not stop the vehicle immediately. Drive
on for a short while. This allows the airflow to
cool the brakes more quickly.
Wet roads
If you have driven for a long time in heavy rain
without braking, there may be a delayed reac-
tion from the brakes when braking for the first
time. This may also occur after the vehicle has
been washed or driven through deep water.
You have to depress the brake pedal more
firmly. Maintain a greater distance from the
vehicle in front.
After driving on a wet road or having the vehicle
washed, brake firmly while paying attention to
the traffic conditions. This will warm up the
brake discs, thereby drying them more quickly
and protecting them against corrosion.
Limited braking performance on salt-
treated roads
If you drive on salted roads, a layer of salt resi-
due may form on the brake discs and brake
pads. This can result in a significantly longer
braking distance.
RIn order to prevent any salt build-up, apply the
brakes occasionally while paying attention to
the traffic conditions.
RCarefully depress the brake pedal and the
beginning and end of a journey.
RMaintain a greater distance to the vehicle
ahead.
Servicing the brakes
!The brake fluid level may be too low, if:
Rif the red brake warning lamp lights up in
the instrument cluster and
Ryou hear a warning tone while the engine is
running
Observe additional warning messages in the
multifunction display.
The brake fluid level may be too low due to
brake pad wear or leaking brake lines.
Have the brake system checked immediately.
Consult a qualified specialist workshop to
arrange this.
!Vehicles with 4MATIC: function or per-
formance tests may only be carried out on a 2-
axle dynamometer. If you wish to operate the
vehicle on such a dynamometer, please con-
sult a qualified specialist workshop in
advance. You could otherwise damage the
drive train or the brake system.
!Vehicles with 4MATIC: the ESP®system
operates automatically. If the electric parking
brake is tested on a brake dynamometer, the
engine and ignition must be switched off: turn
the SmartKey in the ignition lock to position
u or1 or press the Start/Stop button
repeatedly in accordance with the given
SmartKey positions.
Braking triggered automatically by ESP
®may
cause severe damage to the brake system.
All checks and maintenance work on the brake
system must be carried out at a qualified spe-
cialist workshop.
Have brake pads installed and brake fluid
replaced at a qualified specialist workshop.
If the brake system has only been subject to
moderate loads, you should test the functional-
ity of your brakes at regular intervals.
Information on BAS (Brake Assist System)
(
Ypage 66) and Active Brake Assist with cross-
traffic function (Ypage 73).
Driving tips167
Driving and parking
Z

For safety reasons, Mercedes-Benz recom-
mends only installing the following brake disks
and brake pads/linings:
Rbrake disks that have been approved by
Mercedes-Benz
Rbrake pads/linings that have been approved
by Mercedes-Benz or that are of an equivalent
standard of quality
Other brake disks or brake pads/linings can
compromise the safety of your vehicle.
Always replace all brake disks and brake pads/
linings on an axle at the same time. Always
install new brake pads/linings when replacing
brake disks.
The vehicle is equipped with lightweight brake
disks to which the wheel assembly with rim and
threaded connection is matched.
The use of brake disks other than those
approved by Mercedes-Benz can change the
track width and is subject to approval, if appli-
cable.
Shock-type loads when handling the brake
discs, such as when changing wheels, can lead
to a reduction in comfort when driving with light-
weight brake discs. Avoid shock-type loads on
the lightweight brake disks, particularly on the
brake plate.
Mercedes-Benz recommends that you only use
brake fluid that has been specially approved for
your vehicle by Mercedes-Benz, or which corre-
sponds to an equivalent quality standard. Brake
fluid which has not been approved for
Mercedes-Benz vehicles or which is not of an
equivalent quality could affect your vehicle's
operating safety.
High-performance and ceramic brakes
(Mercedes-AMG vehicles)
The AMG brake systems are designed for heavy
loads. This may lead to noise when braking. This
will depend on:
RSpeed
RBraking force
REnvironmental conditions, such as tempera-
ture and humidity
The wear of individual components of the brake
system, such as the brake pads/linings or brake
discs, depends on the individual driving style
and operating conditions.
For this reason, it is impossible to state a mile-
age that will be valid under all circumstances. An aggressive driving style will lead to high wear.
You can obtain more information on this from a
qualified specialist workshop.
New and replaced brake pads and discs only
reach their optimum braking effect after several
hundred kilometers of driving. Compensate for
this by applying greater force to the brake pedal.
Keep this in mind, and adapt your driving and
braking accordingly during this break-in period.
Excessive heavy braking results in correspond-
ingly high brake wear. If the brake pads/linings
have reached their wear limit, the multifunction
display shows a corresponding message. Espe-
cially for high performance driving, it is impor-
tant to maintain and have the brake system
checked regularly.
Driving on wet roads
Hydroplaning
If water has accumulated to a certain depth on
the road surface, there is a danger of hydro-
planing occurring, even if:
Ryou drive at low speeds
Rthe tires have adequate tread depth
For this reason, in the event of heavy rain or in
conditions in which hydroplaning may occur,
you must drive in the following manner:
Rlower your speed
Ravoid ruts
Ravoid sudden steering movements
Rbrake carefully
Driving on flooded roads
!Bear in mind that vehicles traveling in front
or in the opposite direction create waves. This
may cause the maximum permissible water
depth to be exceeded.
Failure to observe these notes may result in
damage to the engine, electrical systems and
transmission.
If you have to drive on stretches of road on which
water has collected, please bear in mind that:
Rin the case of standing water, the water level may be no higher than the lower edge of the
vehicle body
Ryou should drive no faster than walking pace
168Driving tips
Driving and parking

Rear view camera
General notes
Rear view camera :is an optical parking and
maneuvering aid. It shows the area behind the
vehicle with guide lines in the multimedia sys-
tem.
The area behind the vehicle is displayed as a
mirror image, as in the rear view mirror.
iThe text shown in the multimedia system
depends on the language setting. The follow-
ing are examples of rear view camera displays
in the multimedia system.
Important safety notes
The rear view camera is only an aid. It is not a
replacement for your attention to your immedi-
ate surroundings. You are always responsible
for safe maneuvering and parking. Make sure
that there are no persons, animals or objects in
the maneuvering area while maneuvering and
parking in parking spaces.
Under the following circumstances, the rear
view camera will not function, or will function in
a limited manner:
Rif the trunk lid is open
Rin heavy rain, snow or fog
Rat night or in very dark places
Rif the camera is exposed to very bright light
Rif the area is lit by fluorescent bulbs or LED
lighting (the display may flicker)
Rif there is a sudden change in temperature,
e.g. when driving into a heated garage in win- ter
Rif the camera lens is dirty or obstructed.
Observe the notes on cleaning
(
Ypage 313)
Rif the rear of your vehicle is damaged. In this
case, have the camera position and setting
checked at a qualified specialist workshop
The field of vision and other functions of the rear
view camera may be restricted due to additional
accessories on the rear of the vehicle (e.g.
license plate holder, rear bicycle rack).
The rear view camera is protected from rain-
drops and dust by means of a flap. When the rear view camera is acti vated
, this flap opens.
The flap closes again when:
Ryou have finished the maneuvering process
Ryou switch off the engine
Ryou open the trunk
Observe the notes on cleaning (
Ypage 313).
For technical reasons, the flap may remain open
briefly after the rear view camera has been
deactivated.
Activating/deactivating the rear view
camera
XTo activate: make sure that the Activa‐
tion by R gearfunction is selected in the
multimedia system (see the Digital Operator's
Manual).
XEngage reverse gear.
The rear view camera flap opens. The multi-
media system shows the area behind the vehi-
cle with guide lines.
The image from the rear view camera is avail- able throughout the maneuvering process.
XTo deactivate: shift the transmission to posi-
tion j.
or
XTo deactivate: Drive forwards at a speed
greater than 7 mph (12 km/h).
Driving systems191
Driving and parking
Z

Display messagesPossible causes/consequences andMSolutions
The yellow!warning lamp lights up and th ered F (USAonly)
or ! (Canada only) indicator lamp flashes .
It is no tpossibl eto apply th eelectric parking brak emanually.
XShift th etransmission to position j.
XVisitaqualified specialist workshop .
$(USAonly)
J(Canada only)
Check Brake Fluid
Level
There is no tenough brak efluid in th ebrak efluid reservoir .
In addition ,th e$ (USAonly) or J(Canada only) warning lamp
lights up in th einstrumen tcluste rand awarning tone sounds.
GWARNIN G
The braking effec tmay be impaired.
There is aris kof an accident.
XPull ove rand stop th evehicl esafely as soo nas possible, payin g
attention to roa dand traffic conditions. Do no tcontinu edrivin g
under any circumstances.
XSecur eth evehicl eagainst rollin gaway (Ypage 161).
XConsult aqualified specialist workshop .
XDo notadd brak efluid .This does no tcorrec tth emalfunction .
#
CheckBrakePadWear
The brak epads/linings hav ereached their wear limit.
US Aonly: th e$ red brak esystem warning lamp is lit while th e
engin eis running.
XVisit aqualified specialist workshop .
G
Inoperative
Oneor mor emain features of th embrace system are malfunctioning .
XVisitaqualified specialist workshop .
ActiveBrakeAssistFunctionsCurrentlyLimitedSee Opera‐tor's Manual
Active Brake Assis tis temporarily inoperative.
Possibl ecauses are:
RThe radar sensor system is temporarily inoperative, e.g. due to
electromagneti cradiation emitted by nearby TV or radi ostation sor
other source sof electromagneti cradiation .
RThe system is outside th eoperating temperature range.
RThe on-boar dvoltag eis to olow.
Whe nth ecauses state dabov eno longer apply, th edisplay message
disappears.
Active Brake Assis tis operational again .
If th edisplay message does no tdisappear :
XPull overand stop th evehicl esafely as soo nas possible, payin g
attention to roa dand traffic conditions.
XSecur eth evehicl eagainst rollin gaway (Ypage 161).
XRestart th eengine.
236Display messages
On-board computer and displays

Engine
Warning/
indicator
lampNSignal type
Possible causes/consequences and M
Solutions
;NThe yellow Check Engine warning lamp lights up while the engine is running.
There may be a malfunction, for example:
Rin the engine management
Rin the fuel injection system
Rin the exhaust system
Rin the ignition system (for vehicles with gasoline engines)
Rin the fuel system
The emission limit values may be exceeded and the engine may be in emergency
mode.
XVisit a qualified specialist workshop immediately.
In some states, you must immediately visit a qualified specialist workshop as soon as the yellow Check Engine warning lamp lights up. This is due to the legal require-
ments in effect in these states. If in doubt, check whether such legal regulations
apply in the state in which you are currently driving.
Vehicles with a diesel engine: the fuel tank has been run dry (
Ypage 158).
XStart the engine three to four times after refueling.
If the yellow Check Engine warning lamp goes out, emergency running mode is
canceled. The vehicle need not be checked.
8N The yellow reserve fuel warning lamp lights up while the engine is running.
The fuel level has dropped into the reserve range.
XRefuel at the nearest gas station.
8N The yellow reserve fuel warning lamp flashes while the vehicle is in motion.
In addition, the ;Check Engine warning lamp may light up.
The fuel filler cap is not closed correctly or the fuel system is leaking.
XCheck that the fuel filler cap is correctly closed.
XIf the fuel filler cap is not correctly closed: close the fuel filler cap.
XIf the fuel filler cap is closed:visit a qualified specialist workshop.
?NThe red coolant warning lamp lights up while the engine is running and the
coolant temperature gauge is at the start of the scale.
The temperature sensor for the coolant temperature gauge is malfunctioning.
The coolant temperature is no longer being monitored. There is a risk of engine
damage if the coolant temperature is too high.
XPull over and stop the vehicle safely and switch off the engine, paying attention
to road and traffic conditions. Do not continue driving under any circumstances.
XSecure the vehicle against rolling away (Ypage 161).
XConsult a qualified specialist workshop.
Warning and indicator lamps in the instrument cluster265
On-board computer and displays
Z

battery charger which has been tested and
approved by Mercedes-Benz. A battery charger
unit specially adapted for Mercedes-Benz vehi-
cles and tested and approved by Mercedes-
Benz is available as an accessory. It permits the
charging of the battery in its installed position.
Contact an authorized Mercedes-Benz Center
for further information and availability. Read the
battery charger's operating instructions before
charging the battery.
All vehicles except vehicles with a lithium-
ion battery:if the warning and indicator lamps
on the instrument cluster do not light up at low
temperatures, it is very likely that the dis- charged battery has frozen. In this case you may
neither jump-start the vehicle nor charge the
battery. The service life of a thawed-out battery
may be shorter. The starting characteristics can
be impaired, particularly at low temperatures.
Have the thawed-out battery checked at a quali-
fied specialist workshop.
Vehicles with a lithium-ion battery: at low
temperatures, do not charge a battery which has
been removed using a battery charger. Allow the
battery to warm up gently first, if necessary.
Otherwise, the service life can be shortened and
the starting characteristics impaired, especially at low temperatures.
Jump-starting
Hybrid vehicles: make sure that you read the separate operating instructions. You could otherwise
fail to recognize dangers, e.g. due to high voltage.
For the jump-starting procedure, use only the jump-starting connection point in the engine com-
partment, consisting of a positive terminal and a ground point.
All vehicles except vehicles with a lithium-ion battery:
GWARNING
Battery acid is caustic. There is a risk of injury.
Avoid contact with skin, eyes or clothing. Do not inhale any battery gases. Do not lean over the
battery. Keep children away from batteries. Wash away battery acid immediately with plenty of
clean water and seek medical attention.
GWARNING
During charging and jump-starting, explosive gases can escape from the battery. There is a risk of an explosion.
Particularly avoid fire, open flames, creating sparks and smoking. Ensure there is sufficient ven-
tilation while charging and jump-starting. Do not lean over a battery.
GWARNING
During the charging process, a battery produces hydrogen gas. If a short circuit occurs or sparks
are created, the hydrogen gas can ignite. There is a risk of an explosion.
RMake sure that the positive terminal of a connected battery does not come into contact with
vehicle parts.
RNever place metal objects or tools on a battery.
RIt is important that you observe the described order of the battery terminals when connecting
and disconnecting a battery.
RWhen jump-starting, make sure that the battery poles with identical polarity are connected.
RIt is particularly important to observe the described order when connecting and disconnecting
the jumper cables.
RNever connect or disconnect the battery terminals while the engine is running.
Jump-starting325
Breakdown assistance
Z

GWARNING
A discharged battery can freeze at temperatures below freezing point. When jump-starting the
vehicle or charging the battery, gases can escape from the battery. There is a risk of an explosion. Allow the frozen battery to thaw out before charging it or jump-starting.
If the warning and indicator lamps do not light up on the instrument cluster when temperatures are low, it is probably because the discharged battery has frozen. In this case, you may neither charge
the battery nor jump-start the vehicle. The service life of a thawed-out battery may be shorter. The
starting characteristics can be impaired, particularly at low temperatures. Have the thawed-out
battery checked at a qualified specialist workshop.
All vehicles:
!Vehicles with a gasoline engine: avoid repeated and lengthy starting attempts. Otherwise, the
catalytic converter could be damaged by non-combusted fuel.
Do not start the vehicle using a rapid charging device. If your vehicle's battery is discharged, the
engine can be jump-started from another vehicle or from a second battery using jumper cables.
Observe the following points:
RThe battery is not accessible in all vehicles. If the other vehicle's battery is not accessible, jump-
start the vehicle using a second battery or a jump-starting device.
RVehicles with a gasoline engine: only jump-start the vehicle when the engine and exhaust
system are cold.
RAll vehicles except vehicles with a lithium-ion battery: do not start the engine if the battery
is frozen. Let the battery thaw first.
RJump-starting may be performed only using batteries with a nominal voltage of 12 V.
ROnly use jumper cables which have a sufficient cross-section and insulated terminal clamps.
RIf the battery is fully discharged, leave the battery that is being used to jump-start connected for
a few minutes before attempting to start. This charges the battery slightly.
RMake sure that the two vehicles do not touch.
Make sure that:
RThe jumper cables are not damaged.
RBare parts of the terminal clamp do not come into contact with other metal parts while the jumper
cables are connected to the battery.
RThe jumper cables cannot come into contact with parts that can move when the engine is running,
such as the V-belt pulley or the fan.
XSecure the vehicle by applying the electric parking brake.
XShift the transmission to position j.
XMake sure that the ignition is switched off. All indicator lamps in the instrument cluster must be
off. When using the SmartKey, turn the SmartKey to position uin the ignition lock and remove it
(
Ypage 136).
XSwitch off all electrical consumers, e.g. rear window defroster, lighting, etc.
XOpen the hood.
326Jump-starting
Breakdown assistance