Get Maintenance and care Guide for Mercedes C Class 4 Door Fourth Generation (2014-2021)

Maintenance and care 371

Information on regular maintenance work

Mercedes-Benz recommends avoiding such

operating conditions.

You can obtain information concerning the serv‐

icing of your vehicle from a qualified specialist

workshop, e.g. a Mercedes-Benz Service Centre.

ASSYST PLUS service interval display

Function of the ASSYST PLUS service interval

display

NOTE Premature wear through failure to

observe service due dates

*

The ASSYST PLUS service interval display on the

instrument display provides information on the

remaining time or distance before the next

service due date.

You can hide this service display using the back

button on the left-hand side of the steering

wheel.

Depending on how the vehicle is used, the

ASSYST PLUS service interval display may

shorten the service interval, e.g. in the following

cases:

Service work which is not carried out at the

right time or incompletely can lead to

increased wear and damage to the vehicle.

Displaying the service due date

#

Always observe the prescribed service

intervals.

On-board computer:

4

5

Service

ASSYST PLUS

#

Always have the prescribed service

The next service due date is displayed.

work carried out at a qualified specialist

workshop.

#

To exit the display: press the back button

on the left-hand side of the steering wheel.

Bear in mind the following related topic:

Special service requirements

R

Operating the on-board computer

(/ page 245).

R

mainly short-distance driving

The prescribed service interval is based on nor‐

mal operation of the vehicle. Maintenance work

will need to be performed more often if the vehi‐

cle is operated under arduous conditions or

increased loads.

R

when the engine is often left idling for long

periods

R

in the event of frequent cold start phases

R

vehicles with a diesel particulate filter: in

The ASSYST PLUS service interval display is only

an aid. The driver of the vehicle bears responsi‐

bility as regards to whether maintenance work

needs to be performed more often than speci‐

the event of frequently interrupted regenera‐

tion of the diesel particulate filter

372 Maintenance and care

Battery disconnection periods

Resetting the active bonnet

fied based on the actual operating conditions

and/or loads.

Examples of arduous operating conditions:

The ASSYST PLUS service interval display

can only calculate the service due date when

the battery is connected.

&

WARNING Risk of burns from hot com‐

ponent parts in the engine compartment

R

regular city driving with frequent intermedi‐

ate stops

Certain component parts in the engine com‐

partment can be very hot, e.g. the engine,

the cooler and parts of the exhaust system.

#

Note down the service due date displayed on

R

mainly short-distance driving

the instrument display before disconnecting

the battery (/ page 371).

R

frequent operation in mountainous terrain or

on poor road surfaces

#

Allow the engine to cool down and only

touch component parts described in

the following.

R

when the engine is often left idling for long

periods

Engine compartment

Active bonnet (pedestrian protection)

R

operation in particularly dusty conditions

Operation of the active bonnet (pedestrian

protection)

In certain accident situations, the actuation of

the active bonnet reduces the risk of injury to

pedestrians. The rear area of the bonnet is

raised by approximately 85 mm.

For the drive to the workshop, reset the actuated

active bonnet yourself (/ page 372).

After the active bonnet has been actuated,

pedestrian protection may be limited.

and/or if air-recirculation mode is frequently

used

In these or similar operating conditions, have the

interior air filter, engine air cleaner, engine oil

and oil filter etc. changed more frequently. The

tyres must be checked more frequently if the

vehicle is operated under increased loads. Fur‐

ther information can be obtained at a qualified

specialist workshop.

Have the full functionality of the active bonnet

restored in a qualified specialist workshop.

Maintenance and care 373

#

With your hand flat, push down active bonnet

1 in the area around the hinges on both

sides (arrows).

In doing so, the actuator is depressurised

and you may hear a hissing sound.

&

WARNING Risk of accident and injury

when opening and closing the bonnet

WARNING Risk of injury due to moving

parts

The bonnet may suddenly drop into the end

position.

There is a risk of injury for anyone in the bon‐

net's range of movement.

Components in the engine compartment may

continue running or start up suddenly, even if

the ignition is switched off.

Make sure of the following before performing

tasks in the engine compartment:

The engine bonnet must engage in position.

If the active bonnet can be raised slightly at

the rear in the area of the hinges, repeat the

step until it engages correctly.

#

Open or close the bonnet only when

there is nobody in the bonnet's range of

movement.

#

Switch the ignition off.

Never reach into the danger zone sur‐

#

rounding moving components, e.g. the

rotation area of the fan.

Remove jewellery and watches.

Keep items of clothing and hair away

from moving parts.

Opening and closing the bonnet

&

WARNING Danger of burns when open‐

ing the bonnet

#

&

WARNING Risk of accident due to driv‐

ing with the bonnet unlocked

#

If you open the engine bonnet when the

engine has overheated or during a fire in the

engine compartment, you could come into

contact with hot gases or other escaping

operating fluids.

The bonnet may open and block your view.

#

Never release the bonnet when driving.

&

WARNING Risk of injury from touching

components under voltage

#

Before every trip, ensure that the

engine bonnet is locked.

#

Before opening the bonnet, allow the

engine to cool down.

In the event of a fire in the engine com‐

partment, keep the engine bonnet

closed and call the fire service.

The ignition system and the fuel injection

system work under high voltage. You could

receive an electric shock.

#

374 Maintenance and care

#

Never touch components of the ignition

system or the fuel injection system

when the ignition is switched on.

NOTE Plug-in hybrid

*

#

Observe the notes in the Supplement.

You could otherwise fail to recognise

dangers.

&

WARNING Risk of burns from hot com‐

ponent parts in the engine compartment

Opening the bonnet

Certain component parts in the engine com‐

partment can be very hot, e.g. the engine,

the cooler and parts of the exhaust system.

#

Allow the engine to cool down and only

touch component parts described in

the following.

&

WARNING Risk of injury from using the

windscreen wipers while the engine bon‐

net is open

#

Push handle 1 of the bonnet catch upwards

and lift the bonnet by approximately 40 cm.

When the engine bonnet is open, and the

windscreen wipers are set in motion, you can

be trapped by the wiper linkage.

Closing the bonnet

#

Lower the bonnet to a height of around

20 cm and then allow it to fall, applying a lit‐

tle force as you let it go.

#

Always switch off the windscreen wip‐

ers and ignition before opening the

engine bonnet.

#

To release the bonnet, pull on handle 1.

Maintenance and care 375

Park the vehicle on a level surface.

#

R

If the bonnet can still be lifted slightly, open

the bonnet again and close it with a little

more force until it engages correctly.

The engine has an oil dipstick. If not, the

engine oil level can be checked only with the

on-board computer (/ page 375) .

Pull oil dipstick 1 out and wipe off.

Slowly slide oil dipstick 1 into the guide

tube to the stop, and pull it out again after

approximately three seconds.

Depending on the engine, the oil dipstick may be

installed in the engine compartment in different

locations.

The waiting time before checking the oil level

when the engine is at normal operating tempera‐

ture is five minutes.

Engine oil

R

oil level is correct: oil level is between 2

and 3.

Checking the engine oil level using the oil

dipstick

R

oil level too low: oil level is at 3 or

below.

&

WARNING Risk of burns from hot com‐

ponent parts in the engine compartment

oil level too high: oil level is above 2.

#

Certain component parts in the engine com‐

partment can be very hot, e.g. the engine,

the cooler and parts of the exhaust system.

If the oil level is too low, top up with 1 litre of

engine oil.

If the oil level is too high, drain off excess

engine oil. Consult a qualified specialist

workshop.

#

Allow the engine to cool down and only

touch component parts described in

the following.

Checking the engine oil level using the on-

board computer

Requirements:

NOTE Plug-in hybrid

*

#

Observe the notes in the Supplement.

You could otherwise fail to recognise

dangers.

R

The engine has an oil level sensor. If not, the

engine oil level can be checked only with the

oil dipstick (/ page 375).

R

the engine has been warmed up.

Requirements:

376 Maintenance and care

#

R

Topping up engine oil

the vehicle is parked on a level surface.

The engine is running at idle speed.

Add 1 l of engine oil.

R

Reduce engine oil level and the bar display

for indicating the oil level on the multifunc‐

tion display is orange and is above "max":

&

WARNING Risk of burns from hot com‐

ponent parts in the engine compartment

The engine oil level is determined during driving.

Determining the engine oil level can take up to

30 minutes with a normal driving style and even

longer with an active driving style.

Certain component parts in the engine com‐

partment can be very hot, e.g. the engine,

the cooler and parts of the exhaust system.

#

Drain off any excess engine oil that has been

added. To do so, consult a qualified specialist

workshop.

On-board computer:

4

#

Allow the engine to cool down and only

R

For engine oil level turn on ignition

5

Service

Engine oil level

touch component parts described in

the following.

#

You will see one of the following messages on

the multifunction display:

Switch on the ignition to check the engine oil

level.

R

&

Engine oil level Measuring now: measure‐

ment of the oil level is not yet possible.

WARNING Risk of fire and injury from

engine oil

Engine oil level System inoperative: The oil

level sensor is defective or not connected.

#

If engine oil comes into contact with hot

component parts in the engine compart‐

ment, it may ignite.

#

Repeat the request after a maximum of

Consult a qualified specialist workshop.

30 minutes' driving.

R

Engine oil level System currently unavail.

R

Engine oil level OK and the bar display for

#

Close the bonnet.

#

Make sure that no engine oil is spilled

next to the filler opening.

indicating the oil level on the multifunction

display is green and is between "min" and

"max": the oil level is correct.

#

Allow the engine to cool off and thor‐

oughly clean the engine oil from compo‐

nent parts before starting the vehicle.

R

Engine oil level Add 1.0 l and the bar display

for indicating the oil level on the multifunc‐

tion display is orange and is below "min":

Maintenance and care 377

Checking the coolant level

the vehicle is new or if you frequently drive

at high engine speeds.

NOTE Engine damage caused by an

incorrect oil filter, incorrect oil or addi‐

tives

*

&

WARNING Risk of burns from hot com‐

ponent parts in the engine compartment

#

Do not use engine oils or oil filters

which do not correspond to the specifi‐

cations explicitly prescribed for the

service intervals.

Follow the instructions on the service

interval display for changing the engine

oil and observe the prescribed change

intervals.

Certain component parts in the engine com‐

partment can be very hot, e.g. the engine,

the cooler and parts of the exhaust system.

#

Allow the engine to cool down and only

#

touch component parts described in

the following.

&

WARNING Risk of scalding from hot

coolant

#

Do not use additives.

If you open the cap, you could be scalded.

NOTE Damage caused by topping up too

much engine oil

*

#

Let the motor cool down before opening

the cap.

Too much engine oil can damage the engine

or the catalytic converter.

#

When opening the cap, wear protective

gloves and safety glasses.

#

Turn cap 1 anti-clockwise and remove it.

#

Have excess engine oil removed at a

qualified specialist workshop.

Top up the engine oil.

Replace cap 1 and turn it clockwise until it

engages.

#

Open the cap slowly to release pres‐

sure.

% Depending on driving style, the vehicle con‐

sumes up to 0.8 l of oil per 1000 km. The oil

consumption may be higher than this when

#

Check the oil level again (/ page 375).

378 Maintenance and care

#

Continue turning cap 1 anti-clockwise and

#

Allow the engine to cool down and only

touch component parts described in

the following.

remove it.

The coolant level is correct in the following

cases:

&

WARNING ‑ Risk of fire and injury due to

windscreen washer concentrate

R

if the engine is cold, the coolant is up to

marker bar 2.

Windscreen washer concentrate is highly

flammable. It could ignite if it comes into

contact with hot engine component parts or

the exhaust system.

R

if the engine is warm, the coolant is up to

1.5 cm over the marker bar 2.

#

If necessary, top up with coolant that has

been approved for Mercedes-Benz.

#

Make sure that no windscreen washer

R

Further information on coolant

concentrate spills out next to the filler

opening.

(/ page 437).

Topping up the windscreen washer system

#

Park the vehicle on a level surface.

#

&

WARNING Risk of burns from hot com‐

ponent parts in the engine compartment

Check the coolant temperature display in the

instrument cluster.

The coolant temperature must be below

70°C.

Slowly turn cap 1 anti-clockwise to release

overpressure.

Certain component parts in the engine com‐

partment can be very hot, e.g. the engine,

the cooler and parts of the exhaust system.

#

Maintenance and care 379

Active Parking Assist

Cleaning and care

R

Information on washing the vehicle in a car

wash

To avoid damage to the vehicle, deactivate

these systems in the following or similar sit‐

uations:

&

WARNING Risk of an accident due to

reduced braking power after washing the

vehicle

#

during towing

#

in a car wash

Braking efficiency is reduced after washing

the vehicle.

NOTE Damage due to unsuitable car

wash

*

#

After the vehicle has been washed,

#

Before driving into a car wash make

sure that the car wash is suitable for

the vehicle dimensions.

brake carefully while paying attention to

the traffic conditions until braking

power has been fully restored.

#

Ensure there is sufficient ground clear‐

ance between the underbody and the

guide rails of the car wash.

Ensure that the clearance width of the

car wash, in particular the width of the

guide rails, is sufficient.

NOTE Damage from automatic braking

*

#

Remove cap 1 by the tab.

If one of the following functions is switched

on, the vehicle brakes automatically in cer‐

tain situations:

Top up the washer fluid.

Keeping the air-water duct free

R

Active Brake Assist

Active Distance Assist DISTRONIC

HOLD function

#

Keep the area between the bonnet and the

windscreen free of deposits, e.g. ice, snow

and leaves.

R

380 Maintenance and care

To avoid damage to your vehicle when using a

car wash, ensure the following beforehand:

% If, after the car wash, you remove the wax

from the windscreen and wiper rubbers, this

will prevent smearing and reduce wiper

noise.

To avoid damage to your vehicle, observe the fol‐

lowing when using a high-pressure cleaner:

R

Active Distance Assist DISTRONIC is deacti‐

vated.

keep the key at least 3 m away from the vehi‐

cle. Otherwise the boot lid could open unin‐

tentionally.

R

The HOLD function is switched off.

Information on using a high-pressure cleaner

R

maintain a distance of at least 30 cm to the

vehicle.

R

the 360° Camera or the reversing camera is

switched off.

&

WARNING Risk of an accident when

using high-pressure cleaners with round-

spray nozzles

R

vehicles with decorative foil: parts of your

R

the side windows and sliding sunroof are

completely closed.

vehicle are covered with a decorative foil.

Maintain a distance of at least 70 cm

between the foil-covered parts of the vehicle

and the nozzle of the high-pressure cleaner.

Move the high-pressure cleaner nozzle

around whilst cleaning. The water tempera‐

ture of the high-pressure cleaner must not

exceed 60°C.

R

the blower for the ventilation/heating is

switched off.

The water jet can cause externally invisible

damage.

Components damaged in this way may unex‐

pectedly fail.

R

the windscreen wiper switch is in position

g.

R

the key is at a minimum distance of 3 m

#

Do not use a high-pressure cleaner with

round-spray nozzles.

away from the vehicle. Otherwise the boot lid

could open unintentionally.

R

observe the information on the correct dis‐

#

Have damaged tyres or chassis parts

replaced immediately.

tance in the equipment manufacturer's oper‐

ating instructions.

R

in car washes with a conveyor system: neu‐

tral i is engaged.

R

do not direct the nozzle of the high-pressure

% In car washes with a conveyor system: if you

leave the vehicle while it is being washed,

make sure the key is located in the vehicle.

The park position j is otherwise automati‐

cally engaged.

cleaner directly at sensitive parts, e.g. tyres,

gaps, electrical components, batteries, light

sources and ventilation slits.

Maintenance and care 381

Washing the vehicle by hand

Paint

R

Do not use car wash programmes with a final

hot wax treatment.

Do not use paint cleaners, buffing or polish‐

ing products, gloss preservers, e.g. wax.

Always have paintwork repairs carried out at

a qualified specialist workshop.

R

Insect remains: soak with insect remover and

rinse off the treated areas afterwards.

NOTE Engine damage due to water

ingress

*

R

Bird droppings: soak with water and rinse off

afterwards.

Tree resin, oils, fuels and greases: remove by

rubbing gently with a cloth soaked in petro‐

leum ether or lighter fluid.

#

Take care not to point the water jet

directly towards the air inlet grille below

the bonnet.

Notes on cleaning decorative foils

observe the legal requirements, e.g. in a number

of countries, washing by hand is only permitted

in specially designated wash bays.

R

Coolant and brake fluid: remove with a damp

cloth and clean water.

Observe the notes on matt finish care in the

chapter "Notes on paintwork/matt finish paint‐

work care" (/ page 381). They also apply to

matt decorative foils.

Observe the notes on cleaning decorative foils to

avoid vehicle damage.

R

Tar stains: use tar remover.

Wax: use silicone remover.

Do not attach stickers, films or similar mate‐

rials.

#

Use a mild cleaning agent, e.g. car shampoo.

#

Wash the vehicle with lukewarm water using

a soft car sponge. When doing so, do not

expose the vehicle to direct sunlight.

R

Remove dirt immediately, where possible.

#

Carefully hose the vehicle off with water and

dry using a chamois.

Cleaning

R

For cleaning, use plenty of water and a mild

cleaning agent without additives or abrasive

substances, e.g. a car shampoo approved for

Mercedes-Benz.

Remove dirt immediately, where possible,

whilst avoiding rubbing too hard. There is

otherwise a risk of damaging the decorative

foil irreparably.

Matt finish

R

Only use care products approved for

Mercedes-Benz.

Notes on paintwork/matt finish paintwork

care

R

Do not polish the vehicle and light-alloy

wheels.

Only use car washes that correspond to the

latest engineering standards.

R

Observe the notes on cleaning and care to avoid

damaging the paintwork.

382 Maintenance and care

R

Notes on care of car parts

If there is dirt on the finish or if the decora‐

tive foil is dull: use the Paint Cleaner recom‐

mended and approved for Mercedes-Benz.

Insect remains: soak with insect remover and

rinse off the treated areas afterwards.

Bird droppings: soak with water and rinse off

afterwards.

To prevent water stains, dry a foil-wrapped

vehicle with a soft, absorbent cloth after

every car wash.

Do not treat matt or structured decorative

foils with wax. Permanent stains may occur.

&

WARNING Risk of entrapment if the

windscreen wipers are switched on while

the windscreen is being cleaned

Scratches, corrosive deposits, areas affected by

corrosion and damage caused by incorrect care

cannot always be completely repaired. In such

cases, visit a qualified specialist workshop.

You can obtain more information on care and

cleaning products from the manufacturer.

In the case of foil-wrapped surfaces, optical dif‐

ferences may occur between the surfaces that

were not protected by a decorative foil after

removing a decorative foil.

% Have work or repairs to decorative foils car‐

ried out at a qualified specialist workshop,

e.g. in a Mercedes-Benz Service Centre.

R

If the windscreen wipers are set in motion

while you are cleaning the windscreen or

wiper blades, you can be trapped by the

wiper arm.

#

Always switch off the windscreen wip‐

ers and the ignition before cleaning the

windscreen or wiper blades.

Avoiding damage to the decorative foil

R

The service life and colouring of decorative

foils are impaired by:

&

WARNING Risk of burns from the tail‐

pipe and tailpipe trims

-

sunlight

-

temperature, e.g. hot air blower

The exhaust tailpipe and tailpipe trims can

become very hot. If you come into contact

with these parts of the vehicle, you could

burn yourself.

-

weather conditions

-

stone chippings and dirt

-

chemical cleaning agents

#

Always be particularly careful around

-

oily products

the tailpipe and the tailpipe trims and

supervise children especially closely in

this area.

R

Do not use polish on matt decorative foil.

Polishing will have the effect of shining the

foil-wrapped surface.

Maintenance and care 383

Wiper blades

Tailpipes

#

Allow vehicle parts to cool down before

touching them.

R

Fold out the wiper blades and clean them

using a damp cloth.

Clean with a cleaning agent recommended

for Mercedes-Benz, especially in the winter

and after washing the vehicle.

To avoid damage to the vehicle, observe the

notes on cleaning and care of the following vehi‐

cle parts.

R

Do not clean the wiper blades too often.

R

Do not use acidic cleaning agents.

Exterior lighting

R

Trailer hitch

Clean the lenses with a wet sponge and mild

cleaning agent, e.g. car shampoo.

Only use cleaning agents or cleaning cloths

that are suitable for plastic lenses.

Wheels and rims

R

Remove traces of rust on the ball, e.g. with a

wire brush.

R

Use water and acid-free wheel cleaners.

R

Do not use acidic wheel cleaners to remove

R

Remove dirt with a lint-free cloth.

After cleaning, oil or grease the ball head

lightly.

brake dust. This could damage wheel bolts

and brake components.

Sensors

R

Clean the sensors in the front and rear

R

To avoid corrosion of the brake discs and

R

bumpers with a soft cloth and car shampoo

Observe the notes on care in the trailer hitch

manufacturer's operating instructions.

Do not clean the ball neck with a high-pres‐

sure cleaner or solvent.

brake pads, drive the vehicle for a few

minutes after cleaning before parking it. The

brake discs and brake pads warm up and dry

out.

(/ page 184).

R

When using a high-pressure cleaner, maintain

a minimum distance of 30 cm.

Reversing camera and 360° Camera

Windows

R

Open the camera cover with the multimedia

system (/ page 221).

R

Clean windows inside and outside with a

damp cloth and with a cleaning agent recom‐

mended for Mercedes-Benz.

R

Use clean water and a soft cloth to clean the

camera lens.

R

Do not use dry cloths or abrasive or solvent-

R

Do not use a high-pressure cleaner.

based cleaning agents to clean the inside of

windows.

384 Maintenance and care

Notes on care of the interior

Seat belts

R

Black piano-lacquer look: clean with a damp

cloth and soapy water.

For heavy soiling: use a care product recom‐

mended for Mercedes-Benz.

Do not use solvent-based cleaning agents,

polishes or waxes.

R

Clean with lukewarm and soapy water.

&

WARNING Risk of injury from plastic

parts breaking off after the use of sol‐

vent-based care products

R

Do not use chemical cleaning agents.

Do not dry seat belts by heating them to over

80°C or exposing them to direct sunlight.

Care and cleaning products containing sol‐

vents can cause surfaces in the cockpit to

become porous. When the airbags are

deployed, plastic parts may break away.

Display

R

Roof lining

R

Switch off the display and let it cool down.

Clean with a brush or dry shampoo.

R

Clean the surface carefully with a microfibre

cloth and a suitable display care product

(TFT-LCD).

#

Carpet

R

Do not use any care or cleaning prod‐

ucts containing solvents to clean the

cockpit.

Use a carpet and textile cleaning agent rec‐

ommended for Mercedes-Benz.

R

Do not use any other agents.

Plastic trim

Genuine leather seat covers

&

WARNING Risk of injury or death from

bleached seat belts

R

Clean with a damp microfibre cloth.

Clean with a damp cloth and then wipe with a

dry cloth.

R

For heavy soiling: use a care product recom‐

mended for Mercedes-Benz.

Do not attach stickers, films or similar mate‐

rials.

Do not allow cosmetics, insect repellent or

sun cream to come in contact with the plas‐

tic trim.

R

Bleaching or dyeing seat belts can severely

weaken them.

This can, for example, cause seat belts to

tear or fail in an accident.

Leather care: use a leather care agent that

has been recommended for Mercedes-Benz.

R

Do not allow the leather to become too

damp.

#

R

Never bleach or dye seat belts.

Do not use a microfibre cloth.

DINAMICA seat covers

To avoid damage to the vehicle, observe the

notes on cleaning and care.

Real wood and trim elements

R

Clean with a damp cloth.

R

Clean with a microfibre cloth.

Maintenance and care 385

R

Do not use a microfibre cloth.

Imitation leather seat covers

R

Clean with a damp cloth and 1% soapy water.

R

Do not use a microfibre cloth.

Cloth seat covers

R

Clean with a damp microfibre cloth and 1%

soap solution and allow to dry.

Maintenance and care for Your Mercedes C Class 4 Door Fourth Generation (2014-2021)

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