check engine MERCEDES-BENZ C CLASS 2016 Owner's Guide

Let the engine cool down before you open the
cap. Wear gloves and eye protection. Slowly
open the cap to relieve pressure.
G WARNING
Windshield washer concentrate could ignite if
it comes into contact with hot engine compo-
nents or the exhaust system. There is a risk of
fire and injury.
Make sure that no windshield washer con-
centrate is spilled next to the filler neck.
Checking coolant level
X
Park the vehicle on a level surface.
Only check the coolant level when the vehicle
is on a level surface and the engine has cooled
down. X
Turn the SmartKey to position 2 in the ignition
lock ( Y
page 146).
or X
On vehicles with KEYLESS-GO, press the
Start/Stop button twice ( Y
page 146).X
Check the coolant temperature display in the
instrument cluster ( Y
page 236).
The coolant temperature must be below
158 ‡ (70 †). X
Turn the SmartKey to position 0 in the ignition
lock ( Y
page 146).
or X
On vehicles with KEYLESS-GO, pull the Start/
Stop button from the ignition lock
( Y
page 146). X
Slowly turn cap C half a turn counter-clock-
wise to allow excess pressure to escape. X
Turn cap C further counter-clockwise and
remove it.
If the coolant is at the level of marker bar

ESP ®
(Electronic Stability Program). The oper-
ating safety of your vehicle may be restricted.
You could lose control of the vehicle, for
example: R
when braking R
in the event of abrupt steering maneuvers
and/or when the vehicle's speed is not
adapted to the road conditions
There is a risk of an accident.
In the event of a short circuit or a similar inci-
dent, contact a qualified specialist workshop
immediately. Do not drive any further. You
should have all work involving the battery car-
ried out at a qualified specialist workshop.
For further information about ABS and ESP ®
,
see ( Y
page 68) and ( Y
page 73).
All vehicles except vehicles with a lithium-
ion battery:
G WARNING
Electrostatic build-up can lead to the creation
of sparks, which could ignite the highly explo-
sive gases of a battery. There is a risk of an
explosion.
Before handling the battery, touch the vehicle
body to remove any existing electrostatic
build-up.
The highly flammable gas mixture forms when
charging the battery as well as when jump-start-
ing.
Always make sure that neither you nor the bat-
tery is electrostatically charged. A build-up of
electrostatic charge can be caused, for exam-
ple: R
by wearing clothing made from synthetic
fibers R
due to friction between clothing and seats R
if you push or pull the battery across the car-
pet or other synthetic materials R
if you wipe the battery with a cloth
G WARNING
During the charging process, a battery produ-
ces hydrogen gas. If a short circuit occurs or
sparks are created, the hydrogen gas can
ignite. There is a risk of an explosion. R
Make sure that the positive terminal of a
connected battery does not come into con-
tact with vehicle parts. R
Never place metal objects or tools on a bat-
tery. R
It is important that you observe the descri-
bed order of the battery terminals when
connecting and disconnecting a battery. R
When jump-starting, make sure that the
battery poles with identical polarity are
connected. R
It is particularly important to observe the
described order when connecting and dis-
connecting the jumper cables. R
Never connect or disconnect the battery
terminals while the engine is running.
G WARNING
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 batter-
ies. Wash away battery acid immediately with
plenty of clean water and seek medical atten-
tion.
All vehicles:
H Environmental note
Batteries contain dangerous
substances. It is against the
law to dispose of them with
the household rubbish. They
must be collected separately
and recycled to protect the
environment.
Dispose of batteries in an
environmentally friendly
manner. Take discharged
batteries to a qualified spe-
cialist workshop or a special
collection point for used bat-
teries.
! Have the battery checked regularly at a
qualified specialist workshop.348
Battery (vehicle)
Breakdown assistance

Observe the service intervals in the Mainte-
nance Booklet or contact a qualified specialist
workshop for more information.
! Always have work on batteries carried out at
a qualified specialist workshop. Should it, in
exceptional circumstances, be absolutely
necessary to disconnect the 12-volt battery
yourself, observe the following: R
secure the vehicle to prevent it from rolling
away. R
switch off the ignition. R
always disconnect the negative terminal
clamp first, followed by the positive termi-
nal clamp.
After the battery has been disconnected, the
transmission is locked in position P .
After the work has been done, install the bat-
tery and replace the cover of the positive ter-
minal clamp firmly.
Comply with safety precautions and take pro-
tective measures when handling batteries.
Risk of explosion.
Fire, open flames and smoking are
prohibited when handling the bat-
tery. Avoid creating sparks.
Electrolyte or battery acid is corro-
sive. Avoid contact with skin, eyes or
clothing.
Wear suitable protective clothing,
especially gloves, apron and face-
guard.
Immediately rinse electrolyte or acid
splashes off with clean water. Con-
tact a physician if necessary.
Wear eye protection.
Keep children away.
Observe this Operator's Manual.
For safety reasons, Mercedes-Benz recom-
mends that you only use batteries which have been tested and approved for your vehicle by
Mercedes-Benz. These batteries provide
increased impact protection to prevent vehicle
occupants from suffering acid burns should the
battery be damaged in the event of an accident.
In order for the battery to achieve the maximum
possible service life, it must always be suffi-
ciently charged.
The vehicle battery, like other batteries, can dis-
charge over time if you do not use the vehicle. In
this case, have the battery disconnected at a
qualified specialist workshop. You can also
charge the battery with a charger recommended
by Mercedes-Benz. Contact a qualified special-
ist workshop for further information.
Have the battery condition of charge checked
more frequently if you use the vehicle mainly for
short trips or if you leave it standing idle for a
lengthy period. Consult a qualified specialist
workshop if you wish to leave your vehicle
parked for a long period of time.
Remove the SmartKey if you park the vehicle
and do not require any electrical consumers.
The vehicle will then use very little energy, thus
conserving battery power.
PLUG-IN HYBRID vehicles: if the battery
charge is sufficient, the high-voltage battery can
also supply the 12 V battery. This only happens
if the condition of charge of the 12 V battery
requires this, e.g. after using electrical consum-
ers for an extended period with the engine
switched off. As the on-board voltage is contin-
uously monitored this can also be performed
when the engine is switched off. The condition of
charge of the 12 V battery and the on-board
voltage are thereby kept stable for a longer
period.
High-voltage battery – important
safety notes Only PLUG-IN HYBRID vehicles are equipped
with a high-voltage battery.
G DANGER
The vehicle's high-voltage electrical system is
under high voltage. If you modify components
in the vehicle's high-voltage electrical system
or touch damaged components, you may be
electrocuted. The components in the vehi-
cle's high-voltage electrical system may beBattery (vehicle) 349
Breakdown assistance Z

damaged in an accident, although the damage
is not visible. There is a risk of fatal injury.
Following an accident, do not touch any high-
voltage components and never modify the
vehicle's high-voltage electrical system. Have
the vehicle towed away after an accident and
the vehicle's high-voltage electrical system
checked by a qualified specialist workshop.
G WARNING
In the event of a vehicle fire, the internal pres-
sure of the high-voltage battery can exceed a
critical value. In this case flammable gas
escapes through a ventilation valve on the
underbody. The gas can ignite. There is a risk
of injury.
Leave the danger zone immediately. Secure
the danger area at a suitable distance, whilst
observing legal requirements.
G WARNING
If the housing of the high-voltage battery has
been damaged, electrolyte and gases may
leak out. These are poisonous and caustic.
There is a risk of injury.
Avoid contact with skin, eyes or clothing.
Immediately rinse electrolyte splashes off
with water and seek medical attention
straight away.
! Exhaustive discharge caused by the vehicle
standing idle for lengthy periods can damage
the high-voltage battery. If the vehicle is idle
for lengthy periods leave the high-voltage bat-
tery connected to a charging station.
Consult an authorized Mercedes-Benz Center if
you wish to leave your vehicle parked for a long
period of time.
Charging the 12 V battery
Vehicles with a lithium-ion battery:
! Only use battery chargers with a maximum
charging voltage of 14.4 V.
All other vehicles: G WARNING
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
ventilation while charging and jump-starting.
Do not lean over a battery.
G WARNING
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 batter-
ies. Wash away battery acid immediately with
plenty of clean water and seek medical atten-
tion.
G WARNING
A discharged battery can freeze at tempera-
tures below freezing point. When jump-start-
ing 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.
! Only use battery chargers with a maximum
charging voltage of 14.8 V.
All vehicles:
! Only charge the battery using the jump-
starting connection point.
The jump-starting connection point is in the
engine compartment ( Y
page 352).X
Open the hood. X
Connect the battery charger to the positive
terminal and ground point in the same order
as when connecting the donor battery in the
jump-starting procedure ( Y
page 352).
Keep away from fire and open flames. Do not
lean over a battery. Never charge the battery if it
is still installed in the vehicle, unless you use a
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 the350
Battery (vehicle)
Breakdown assistance

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 indicator/warning lamps in
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.
PLUG-IN HYBRID vehicles: if the battery
charge is sufficient, the high-voltage battery can
also supply the 12 V battery. This only happens
if the condition of charge of the 12 V battery
requires this, e.g. after using electrical consum-
ers for an extended period with the engine
switched off. As the on-board voltage is contin-
uously monitored this can also be performed
whe n the e ngine is switched off. The condition of
charge of the 12 V battery and the on-board
voltage are thereby kept stable for a longer
period. Battery (vehicle) 351
Breakdown assistance Z

Jump-starting 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:
G WARNING
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.
G WARNING
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.
G WARNING
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. R
Make sure that the positive terminal of a connected battery does not come into contact with
vehicle parts. R
Never place metal objects or tools on a battery. R
It is important that you observe the described order of the battery terminals when connecting
and disconnecting a battery. R
When jump-starting, make sure that the battery poles with identical polarity are connected. R
It is particularly important to observe the described order when connecting and disconnecting
the jumper cables. R
Never connect or disconnect the battery terminals while the engine is running.
G WARNING
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.
! Avoid repeated and lengthy starting attempts. Otherwise, the catalytic converter could be
damaged by the non-combusted fuel.
If, at low temperatures, the indicator lamps/warning lamps in the instrument cluster do not light up,
it is highly likely that 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:352
Jump-starting
Breakdown assistance

Tire-mounting tools should not be used near
the valve. This could damage the electronic
components.
Only have tires changed at a qualified spe-
cialist workshop.
Always observe the instructions and safety
notes in the "Mounting a wheel" section
( Y
page 380).
The wear patterns on the front and rear tires
differ, depending on the operating conditions.
Rotate the wheels before a clear wear pattern
has formed on the tires. Front tires typically
wear more on the shoulders and the rear tires in
the center.
On vehicles that have the same size front and
rear wheels, you can rotate the wheels accord-
ing to the intervals in the tire manufacturer's
warranty book in your vehicle documents. If no
warranty book is available, the tires should be
rotated every 3,000 to 6,000 miles (5,000 to
10,000 km). Earlier may be necessary, depend-
ing on the degree of tire wear. Do not change the
direction of wheel rotation.
Clean the contact surfaces of the wheel and the
brake disc thoroughly every time a wheel is rota-
ted. Check the tire pressure and, if necessary,
restart the tire pressure loss warning system
( Y
page 367) or the tire pressure monitor
( Y
page 369).
Direction of rotation Tires with a specified direction of rotation have
additional benefits, e.g. if there is a risk of hydro-
planing. These advantages can only be gained if
the tires are installed corresponding to the
direction of rotation.
An arrow on the sidewall of the tire indicates its
correct direction of rotation.
Storing wheels Store wheels that are not being used in a cool,
dry and preferably dark place. Protect the tires
from oil, grease, gasoline and diesel. Mounting a wheel
Preparing the vehicle X
Stop the vehicle on solid, non-slippery and
level ground. X
Apply the electric parking brake manually. X
Bring the front wheels into the straight-ahead
position. X
Shift the transmission to position P .X
Make sure that the vehicle level is set to "Nor-
mal" on vehicles with AIRMATIC ( Y
page 196).X
Switch off the engine. X
Vehicles without KEYLESS-GO: remove the
SmartKey from the ignition lock. X
Vehicles with KEYLESS-GO start-function
or KEYLESS-GO: open the driver's door.
The on-board electronics now have status 0 .
This is the same as the SmartKey having been
removed. X
Vehicles with KEYLESS-GO start-function
or KEYLESS-GO: remove the Start/Stop but-
ton from the ignition lock ( Y
page 146).X
Make sure that the engine cannot be started
via your smartphone ( Y
page 149).X
If included in the vehicle equipment, remove
the tire-change tool kit from the vehicle. X
Safeguard the vehicle against rolling away.
Securing the vehicle to prevent it from
rolling away
If your vehicle is equipped with a wheel chock, it
can be found in the tire-change tool kit
( Y
page 343).
The folding wheel chock is an additional safety
measure to prevent the vehicle from rolling
away, for example when changing a wheel.380
Changing a wheel
Wheels and tires

i The coolant is checked with every mainte-
nance interval at a qualified specialist work-
shop.
Filling capacities Model Capacity
C 400 4MATIC
Mercedes-Benz
C 450 AMG 4MATIC 11.5 US qt (10.9 l)
Mercedes ‑ AMG
vehicles 11.7 US qt (11.1 l)
Al l ot her models
8.5 US qt (8.0 l)
Windshield/headlamp cleaning sys-
tem
Important safety notes
G WARNING
Windshield washer concentrate could ignite if
it comes into contact with hot engine compo-
nents or the exhaust system. There is a risk of
fire and injury.
Make sure that no windshield washer con-
centrate is spilled next to the filler neck.
! Only use washer fluid that is suitable for
plastic lamp lenses, e.g. MB SummerFit or MB
WinterFit. Unsuitable washer fluid could dam-
age the plastic lenses of the headlamps.
! Do not add distilled or de-ionized water to
the washer fluid container. Otherwise, the
level sensor may be damaged.
! Only MB SummerFit and MB WinterFit
washer fluid should be mixed together. The
spray nozzles may otherwise become
blocked.
When handling washer fluid, observe the impor-
tant safety notes on service products
( Y
page 388).
At temperatures above freezing: X
Fill the washer fluid reservoir with a mixture of
water and windshield washer fluid, e.g. MB
SummerFit.
Add 1 part MB SummerFit to 100 parts water. At temperatures below freezing: X
Fill the washer fluid reservoir with a mixture of
water and washer fluid, e.g. MB WinterFit.
For the correct mixing ratio refer to the infor-
mation on the antifreeze reservoir.
i Add windshield washer fluid, e.g. MB Sum-
merFit or MB WinterFit, to the washer fluid all
year round.
Climate control system refrigerant
Important safety notes The climate control system of your vehicle is fil-
led with refrigerant R ‑ 134a.
The instruction label regarding the refrigerant
type used can be found on the radiator cross
member.
! Only the refrigerant R ‑ 134a and the PAG oil
approved by Mercedes-Benz may be used.
The approved PAG oil may not be mixed with
any other PAG oil that is not approved for
R-134a refrigerant. Otherwise, the climate
control system may be damaged.
Service work, such as topping up refrigerant or
replacing components, may only be carried out
by a qualified specialist workshop. All applicable
regulations, as well as SAE standard J639, must
be adhered to.
Always have work on the climate control system
carried out at a qualified specialist workshop.
Refrigerant instruction label
Example: refrigerant instruction label
C
Warning symbol
D
Refrigerant filling capacity