light MERCEDES-BENZ C CLASS 2016 Repair Manual

Problems with the engine Problem
Possible causes/consequences and P Solutions
The engine does not
start. The starter motor
can be heard. R
There is a malfunction in the engine electronics. R
There is a malfunction in the fuel supply.
Before attempting to start the engine again: X
Turn the SmartKey back to position 0 in the ignition lock.
or X
Press the Start/Stop button repeatedly until all indicator lamps in
the instrument cluster go out. X
Try to start the engine again ( Y
page 148). Avoid excessively long
and frequent attempts to start the engine as these will drain the
battery.
If the engine does not start after several attempts: X
Consult a qualified specialist workshop.
The engine does not
start. You cannot hear
the starter motor. The on-board voltage is too low because the battery is too weak or
discharged. X
Jump-start the vehicle ( Y
page 352).
If the engine does not start despite attempts to jump-start it: X
Consult a qualified specialist workshop.
The starter motor was exposed to a thermal load that was too high. X
Try to start the engine again ( Y
page 148).
If the engine still does not start: X
Consult a qualified specialist workshop.
The engine is not running
smoothly and is misfir-
ing. There is a malfunction in the engine electronics or in a mechanical
component of the engine management system. X
Only depress the accelerator pedal slightly.
Otherwise, non-combusted fuel may get into the catalytic converter
and damage it. X
Have the cause rectified immediately at a qualified specialist work-
shop.
The coolant temperature
gauge shows a value
above 248 ‡ (120 †). The coolant level is too low. The coolant is too hot and the engine is no
longer being cooled sufficiently. X
Stop as soon as possible and allow the engine and the coolant to
cool down. X
Check the coolant level ( Y
page 333). Observe the warning notes
as you do so and add coolant if necessary. Driving 153
Driving and parking Z

Temporary setting X
To activate: shift the DIRECT SELECT lever to
position D .X
Pull steering wheel paddle shifter C or D .
Further information on activating manual gear-
shifting on PLUG-IN HYBRID vehicles
( Y
page 229).
Temporary setting will be active for a certain
amount of time. Under certain conditions the
minimum amount of time is extended, e.g. in the
case of lateral acceleration, during an overrun
phase or when driving on steep terrain. X
To deactivate: pull steering wheel paddle
shifter D and hold it in place.
or X
Use the DIRECT SELECT lever to switch the
transmission position.
or X
Use the DYNAMIC SELECT switch to change
the drive program.
Permanent setting (Mercedes-AMG
vehicles) X
To activate: shift the DIRECT SELECT lever to
position D . X
Press button C .
Indicator lamp D lights up.X
To deactivate: press button C .
or X
If position D (automatic transmission) is
selected for the transmission in drive pro-
gram I : shift to drive program I with the
DYNAMIC SELECT switch.
Indicator lamp D goes out.
Shifting gears
! Mercedes-AMG vehicles: the automatic
transmission does not shift up automatically
even when the engine limiting speed for the
current gear is reached. When the engine lim-
iting speed is reached, the fuel supply is cut to
prevent the engine from overrevving. Always
make sure that the engine speed does not
reach the red area of the tachometer. There is
otherwise a risk of engine damage.
X
To shift up: pull steering wheel paddle
shifter D .
The automatic transmission shifts up to the
next gear.
All vehicles (except Mercedes-AMG vehi-
cles): if the maximum engine speed on the
currently engaged gear is reached and you
continue to accelerate, the automatic trans-
mission automatically shifts up in order to
prevent engine damage. X
To shift down: pull steering wheel paddle
shifter C .
The automatic transmission shifts down to
the next gear.
Automatic down shifting occurs when coast-
ing.162
Automatic transmission
Driving an d parking

Display D
Light s up
green There are no malfunctions.
The high-voltage battery can
be charged.
Light s up red An impermissible curren t is
bein g supplied to th e control
unit. The high-voltage battery
canno t be charged.
i Fo r information on problem s relating to th e
charging process, see ( Y
page 175).
Setting th e maximum charg e curren t
G WARNIN G
If th e charg e curren t draw via a main s socke t
is to o high during th e charging process, th e
external electrical system may overheat.
There is a ris k of fire.
Befor e beginning th e charging process, chec k
th e maximum permissibl e charg e curren t
locally. Consult a qualified exper t to do so
wher e necessary.
If necessary, adjust your vehicle's settings.
! An excessive charg e curren t can blow a fus e
or lead to overheating of th e external powe r
supply. Chec k whether th e external powe r
supply is compatible wit h th e set charg e cur -
rent. If necessary, lower th e set charg e cur -
ren t or use another powe r socket.
You can set a limi t for th e value s of th e charg e
curren t used in charging th e high-voltage bat -
tery. This act s as a mean s of preventing th e
powe r supply from overloading. You can set this
limi t by usin g th e control s on th e charging cable
or in th e on-boar d computer' s menu. Only set
th e maximum charg e curren t in th e on-boar d
computer men u if there are no charg e curren t
setting s on th e charging cable.
The default standard value in th e vehicl e corre-
spond s to th e maximum charg e curren t value .
The default standard value on th e cha rging cable
i
s th e minimum charg e curren t setting . This cor-
responds to th e minimum available charg e cur -
ren t from th e powe r supply. The value on th e
charging cable can be increased and is descri-
bed in th e followin g section . i The value of th e maximum setting and th e
adjustmen t value may var y depending on th e
country.
Befor e charging th e high-voltage battery, chec k
th e maximum permissibl e charg e curren t for th e
relevan t powe r socket. X
To adjust th e setting: press butto n

Indicator
lamp
Lights up
orange A charging break for the high-
voltage battery is taking
place.
The indicator lamp goes out
after approximately
90 seconds.
Lights up
green The high-voltage battery is
fully charged.
The indicator lamp goes out
after approximately
90 seconds.
i If the indicator lamp is off, lock or unlock the
vehicle. The indicator lamp then displays the
current status of the charging process again.
Connecting the charging cable
X
Shift the transmission to position P .X
Switch the ignition off. X
Press the charge socket flap in the direction
of arrow C .
The charge socket flap swings up. X
Press fastener D to the left.
Socket cap

Problems with the charging process Problem
Possible causes/consequences and P Solutions
The charge socket flap
cannot be opened. The charge socket flap is not unlocked. X
Unlock the vehicle ( Y
page 81).
If the key battery is discharged: X
Unlock the driver's door using the mechanical key ( Y
page 83).
or X
Unlock the vehicle centrally from the inside ( Y
page 88).
The charge socket flap is unlocked, but the opening mechanism is
jammed. X
Lock the vehicle and unlock it again.
If, after that, the opening mechanism is still jammed: X
Consult a qualified specialist workshop.
The high-voltage battery
is not being charged. The indicator lamp on the vehicle socket does not light up or flashes
red.
A malfunction has occurred during the initialization of the charging
process or during charging. X
Disconnect the charging cable connector from the vehicle socket
and plug it back into the vehicle socket.
If the problem persists: X
Use a different charging station.
or X
Consult a qualified specialist workshop.
The high-voltage battery
is not charged during the
charging process when
connected to a power
socket. The electrical outlet is faulty. X
Have the electrical outlet checked to test if it is functioning prop-
erly.
or X
Use a different electrical outlet.
The charging cable con-
nector cannot be
removed from the vehi-
cle socket. The snap fastener on the charging cable connector is locked. X
Press and hold the button on the charging cable connector. The
snap fastener on the vehicle socket is unlocked. X
Remove the charging cable connector from the vehicle socket.
If the snap fastener on the charging cable connector is locked: X
Press and hold the button on the charging cable connector and try
to release the lock.Charging the high-voltage battery (PLUG-IN HYBRID vehicles) 175
Driving and parking Z

X
Depress the brake pedal and keep it
depressed. X
Shift to neutral N .X
Release the brake pedal. X
Release the electric parking brake. X
Switch off the ignition and leave the SmartKey
in the ignition lock.
The engine can be switched off in an emergency
while the vehicle is in motion by pressing and
holding the Start/Stop button for three sec-
onds. This function operates independently of
the ECO start/stop automatic engine switch-off
function.
Electric parking brake
General notes
G WARNING
If you leave children unsupervised in the vehi-
cle, they could set it in motion by, for example: R
release the parking brake. R
shift the automatic transmission out of the
parking position P .R
start the engine.
In addition, they may operate vehicle equip-
ment and become trapped. There is a risk of
an accident and injury.
When leaving the vehicle, always take the
SmartKey with you and lock the vehicle. Never
leave children unsupervised in the vehicle.
The function of the electric parking brake is
dependent on the on-board voltage. If the on-
board voltage is low or there is a malfunction in
the system, it may not be possible to apply the
released parking brake. X
If this is the case, only park the vehicle on
level ground and secure it to prevent it rolling
away. X
Shift the automatic transmission to position
P .
It may not be possible to release an applied
parking brake if the on-board voltage is low or
there is a malfunction in the system. Contact a
qualified specialist workshop.
The electric parking brake performs a function
test at regular intervals while the engine is switched off. The sounds that can b e heard while
th
is is occurring are normal.
Applying or releasing manually X
To apply: push handle C .
When the electric parking brake is applied,
the red I (USA only) or $ (Canada
only) indicator lamp lights up in the instru-
ment cluster.
The electric parking brake can also be applied
when the SmartKey is removed. X
To release: pull handle C .
The red I (USA only) or $ (Canada
only) indicator lamp in the instrument cluster
goes out.
The electric parking brake can only be released: R
when the SmartKey is in position 1 or 2 in the
ignition lock ( Y
page 146) or R
if the ignition was switched on using the
Start/Stop button
Applying automatically The electric parking brake is automatically
applied when the transmission is in position P
and: R
the engine is switched off or R
the driver is not wearing a seat belt and the
driver's door is opened.
To prevent the electric parking brake from being
automatically applied, pull handle C .178
Parking
Driving an d parking

In addition to driving style, the actual consump-
tion is affected by other factors, such as: R
load R
tire pressure R
cold start R
choice of route R
electrical consumers switched on
These factors are not included in the ECO dis-
play.
An economical driving style specially requires
driving at moderate engine speeds.
Achieving a higher value in the categories
"Acceleration" and "Constant": R
observe the gearshift recommendations. R
drive in drive program E .
On long journeys at a constant speed, e.g. on the
highway, only the outer area for "constant" will
change.
The ECO display summarizes the driving style
from the start of the journey to its completion.
Therefore, there are more marked changes in
the outer areas at the start of a journey. On lon-
ger journeys, there are fewer changes. For more
marked changes, perform a manual rest
( Y
page 241).
For further information on the ECO display, see
( Y
page 240).
Braking
Important safety notes
G WARNING
If you shift down on a slippery road surface in
an attempt to increase the engine's braking
effect, the drive wheels could lose their grip.
There is an increased danger of skidding and
accidents.
Do not shift down for additional engine brak-
ing on a slippery road surface.
Downhill gradients
! On long and steep gradients, you must
reduce the load on the brakes by shifting early
to a lower gear. This allows you to take
advantage of the engine braking effect and
helps avoid overheating and excessive wear
of the brakes. When you take advantage of the engine brak-
ing effect, 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 warranty.
Heavy and light loads
G WARNING
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.182
Driving tips
Driving and parking

R
In order to prevent any salt build-up, apply the
brakes occasionally while paying attention to
the traffic conditions. R
Carefully depress the brake pedal and the
beginning and end of a journey. R
Maintain a greater distance to the vehicle
ahead.
Servicing the brakes
! The brake fluid level may be too low, if: R
if the red brake warning lamp lights up in
the instrument cluster and R
you 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.
! A function or performance test should only
be carried out on a 2-axle dynamometer. If
you wish to operate the vehicle on such a
dynamometer, please consult a qualified spe-
cialist workshop in advance. You could oth-
erwise damage the drive train or the brake
system.
! The ESP ®
system operates automatically.
The engine and the ignition must therefore be
switched off (the SmartKey must be in posi-
tion 0 or 1 in the ignition lock or the Start/
Stop button must be in position 0 or 1 ) if the
electric parking brake is tested on a brake
dynamometer.
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) ( Y
page 68)
and BAS PLUS (Brake Assist PLUS) ( Y
page 69). For safety reasons, Mercedes-Benz recom-
mends only installing the following brake disks
and brake pads/linings: R
brake disks that have been approved by
Mercedes-Benz R
brake 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 pa ds/linings when replacing
bra
ke 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
disks, such as when changing wheels, can lead
to a reduction in comfort when driving with light-
weight brake disks. 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: R
Speed R
Braking force R
Environmental 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 Driving tips 183
Driving and parking Z

For more information on driving with snow
chains, see ( Y
page 363).
For more information on driving with summer
tires, see ( Y
page 362).
Observe the notes in the "Winter operation" sec-
tion ( Y
page 362).
Driving systems
Mercedes-Benz Intelligent Drive Mercedes-Benz Intelligent Drive stands for inno-
vative driver assistance and safety systems
which enhance comfort and support the driver in
critical situations. With these intelligent co-ordi-
nated systems Mercedes-Benz has set a mile-
stone on the path towards autonomous driving.
Mercedes-Benz Intelligent Drive embraces all
elements of active and passive safety in one well
thought out system – for the safety of the vehi-
cle occupants and that of other road users.
Further information on driving safety systems
( Y
page 67).
Cruise control
General notes Cruise control maintains a constant road speed
for you. It brakes automatically in order to avoid
exceeding the set speed. Change into a lower
gear in good time on long and steep downhill
gradients. This is especially important if the
vehicle is laden. By doing so, you will make use
of the braking effect of the engine. This relieves
the load on the brake system and prevents the
brakes from overheating and wearing too
quickly.
Use cruise control only if road and traffic con-
ditions make it appropriate to maintain a steady
speed for a prolonged period. You can store any
road speed above 20 mph (30 km/h).
Important safety notes
If you fail to adapt your driving style, cruise con-
trol can neither reduce the risk of an accident
nor override the laws of physics. Cruise control
cannot take into account the road, traffic and
weather conditions. Cruise control is only an
aid. You are responsible for the distance to the vehicle in front, for vehicle speed, for braking in
good time and for staying in your lane.
Do not use cruise control: R
in road and traffic conditions which do not
allow you to maintain a constant speed, e.g. in
heavy traffic or on winding roads R
on slippery road surfaces. Braking or accel-
erating could cause the drive wheels to lose
traction and the vehicle could then skid R
when there is poor visibility, e.g. due to fog,
heavy rain or snow
If there is a change of drivers, advise the new
driver of the speed stored.
i The speed indicated in the speedometer
may differ slightly from the speed stored.
Cruise control lever
C
Activates or increases speed D
Activates or reduces speed

Change into a lower gear in good time on long
and steep downhill gradients. This is especially
impo rtant if the veh icle is laden. By doin g so, you
will make use of the braking effect of the engine.
This relieves the load on the brake system and
prevents the brakes from overheating and wear-
ing too quic kly.
If DI ST RONIC PLUS detects that there is a risk of
a co llisio n, you will be warned visually and
acoustically. DI ST RONIC PLUS cannot prevent a
co llisio n wit hout your intervention. An intermit-
tent warning tone will then sound and the dis-
tance warning lamp will light up in the instru-
ment cluster. Brake immediately in order to
increase the dist ance to the veh icle in front or
take evasive action pro vide d it is safe to do so.
DI ST RONIC PLUS operates in range between
0 mph (0 km/h) and 120 mph (200 km/h).
Do not use DI ST RONIC PLUS while driv ing on
roads wit h steep gradients.
As DI ST RONIC PLUS transmits radar waves, it
can resemble the radar detectors of the respon-
sible authorities. You can refer to the relevant
chapter in the Operator's Manual if questions
are asked about this.
i USA only: This device has been appr oved by
the FCC as a "Vehicular Radar System". The
radar sensor is intended for use in an auto-
motive radar system only. Removal, tamper-
in g , or altering of the device will void any war-
ranties, and is not permitted by the FCC. Do
not tamper with, alter, or use in any non-
approved way.
Any unauthorized mod ific ation to th is device
could void the user's authority to operate the
equipm ent.
i Canada only: This device co mplie s wit h
RSS -210 of In dustry Canada. Operation is
subject to the foll owin g two conditions:
1. This device may not cause harmful inter-
ference, and
2. This device must accept any interference
receive d, inc ludin g interference that may
cause undesired operation of the device.
Removal, tampering, or altering of the device
will void any warranties, and is not permitte d.
Do not tamper wit h, alter, or use in any non-
approved way.
Any unauthorized mod ific ation to th is device
could void the user's authority to operate the
equipm ent. Important safety notes
G WARNING
DISTRONIC PLUS does not react to: R
people or animals R
stationary obstacles on the road, e.g. stop-
ped or parked vehicles R
oncoming and crossing traffic
As a result, DI ST RONIC PLUS may neither give
warnings nor intervene in such situations.
There is a risk of an accident.
Alwa ys pay careful attention to the traff ic sit-
uation and be ready to brake.
G WARNING
DISTRONIC PLUS cannot always clearly iden-
tify other road users and co mple x traffic sit-
uations.
In such cases, DI ST RONIC PLUS may: R
give an unnecessary warning and then
brake the vehicle R
neither give a warning nor intervene R
accelerate or brake unexpect edly
There is a risk of an accident.
Continue to drive carefully and be ready to
brake, in particular when warned to do so by
DISTRONIC PLU S.
G WARNING
DISTRONIC PLUS brakes your vehicle with up
to 50 %o f the maximum possible deceleration.
If this braking force is insufficient, DISTRONIC
PLUS warns you visually and audibly. There is
a risk of an accident.
In such cases, apply the brakes yourself and
try to take evasive action.
! If DISTRONIC PLUS or the HOLD function is
activated, the vehicle brakes automatically in
certain situations.
To prevent damage to the vehicle, deactivate
DISTRONIC PLUS and the HOLD function in
the following or other similar situations: R
when towing the vehicle R
in the car washDriving systems 187
Driving and parking Z