Page 140 of 214

ProblemPossible causes/consequences and0050Solutions
00B3
The red oil pressure
indicator lamp is lit
while the engine is
running. A warning
tone also sounds.The engine oil pressure is too low. There is a risk of engine dam-
age.
XPull over and stop the vehicle safely as soon as possible, paying
attention to road and traffic conditions. Do not continue driv-
ing under any circumstances.
XSwitch off the engine.
XSecure the vehicle against rolling away (Ypage 100).
XCheck the oil level (Ypage 150).
XIf necessary, add engine oil (Ypage 150).
Information on approved engine oils can also be obtained from any
qualified specialist workshop.
00AC
The red coolant tem-
perature warning lamp
comes on while the
engine is running. A
warning tone also
sounds.The coolant temperature has exceeded 230 ‡(110 †). The airflow to
the engine radiator may be blocked or the coolant level may be too
low.
GWARNING
The engine is not being cooled sufficiently and may be damaged.
Do not drive when your engine is overheated. This can cause some
fluids which may have leaked into the engine compartment to catch
fire.
Steam from an overheated engine can cause serious burns, which
can occur just by opening the engine compartment cover.
There is a risk of injury.
XPull over and stop the vehicle safely as soon as possible, paying attention to road and traffic conditions. Do not continue driv-
ing under any circumstances.
XSwitch off the engine.
XSecure the vehicle against rolling away (Ypage 100).
XLeave the vehicle and keep a safe distance from the vehicle until
the engine has cooled down.
XCheck the coolant level and top up the coolant. Observe the notes
as you do so (Ypage 210).
XIf you need to add coolant more often than usual, have the engine
coolant system checked.
XMake sure that the air supply to the engine radiator is not
blocked, e.g. by snow, slush or ice.
XDo not start the engine again until the coolant temperature is
below 230 ‡(110 †). Otherwise, the engine could be damaged.
Avoid subjecting the engine to heavy loads, e.g. driving in
mountainous terrain, and stop-and-go traffic.
138Warning and indicator lamps in the instrument cluster
>> On-board computer and displays.
Page 212 of 214

Engine oil viscosity
Viscosity describes the flow characteristics
of a fluid. If an engine oil has a high viscos-
ity, this means that it is thick; a low viscos-
ity means that it is thin.
Select an engine oil with an SAE (viscosity)
classification suitable for the prevailing
outside temperatures. The table shows you
which SAE classifications are to be used. The
low-temperature properties of engine oils
can be significantly impaired during oper-
ation due to, for example, aging or soot and
fuel accretion. It is therefore strongly rec-
ommended that you carry out regular oil
changes using an approved engine oil with
the appropriate SAE classification.
Brake fluid
When handling brake fluid, observe the
important safety notes on service products
(
Ypage 207).
The brake fluid change intervals can be found
in the Maintenance Booklet.
Only use brake fluid approved by Mercedes-
Benz according to MB Approval 331.0.
Information about approved brake fluid can
be obtained at any qualified specialist work-
shop or on the Internet at
http://bevo.mercedes-benz.com.
iHave the brake fluid regularly replaced at
a qualified specialist workshop and the
replacement confirmed in the Maintenance
Booklet.
Coolant
General notes
!Only add coolant that has been premixed
with the desired antifreeze protection.
You could otherwise damage the engine.
Further information on coolants can be
found in the Mercedes-Benz Specifications
for Service Products, MB BeVo 310.1, e.g. on
the Internet at
http://bevo.mercedes-benz.com. Or con-
tact a qualified specialist workshop.
!Always use a suitable coolant mixture,
even in countries where high temperatures
prevail.
Otherwise, the engine cooling system is not sufficiently protected from corrosion and
overheating.
iHave the coolant regularly replaced at a
qualified specialist workshop and the
replacement confirmed in the Maintenance
Booklet.
Comply with the important safety precautions
for service products when handling coolant
(
Ypage 207).
The coolant is a mixture of water and anti-
freeze/corrosion inhibitor. It performs the
following tasks:
Rcorrosion protection
Rantifreeze protection
Rraising the boiling point
If the coolant has antifreeze protection down
to -35 ‡(-37 †), the boiling point of the cool-
ant during operation is approximately 266 ‡
(130 †).
The antifreeze/corrosion inhibitor concen-
tration in the engine cooling system should:
Rbe at least 50 %. This will protect the
engine cooling system against freezing
down to around -13‡(-25 †).
Rnot exceed 50 % (antifreeze protection down
to-35 ‡[-37 †]). Otherwise, heat will not be
dissipated as effectively.
smart recommends an antifreeze/corrosion
inhibitor concentrate in accordance with MB
Specifications for Operating Fluids 310.1 or
325.6.
Antifreeze/corrosion inhibitor concentrate
in accordance with MB Specifications for
210Service products and filling capacities
>> Technical data.
Page 213 of 214

Operating Fluids 310.1 and 325.6 can be mixed
together. An orange discoloration depending
on the mixing ratio does not affect the func-
tion.
iWhen the vehicle is first delivered, it is
filled with a coolant mixture that ensures
adequate antifreeze and corrosion protec-
tion.
iThe coolant is checked with every main-
tenance interval at a qualified specialist
workshop.
Windshield washer system
General notes
!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
important safety notes on service products
(
Ypage 207).
At temperatures above freezing:
XFill the washer fluid reservoir with a mix- ture of water and windshield washer fluid,
e.g. MB SummerFit.
Add 1 part MB SummerFit to 100 parts water.
At temperatures below freezing:
XFill the washer fluid reservoir with a mix-
ture of water and washer fluid, e.g. MB Win-
terFit.
The correct mixing ratio can be taken from
the information on the antifreeze protec-
tion container.
iAdd windshield washer fluid, e.g. MB
SummerFit 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
filled with refrigerant R‑134a.
The instruction label regarding the refrig-
erant type used can be found on the left, on the
underside of the hood.
!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. Other-
wise, 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 must be adhered to,
SAE standard J639 included.
Always have work on the climate control sys-
tem carried out at a qualified specialist
workshop.
Refrigerant instruction label
The refrigerant instruction label:
Ris located at the front on the right on the
body frame.
Rinforms that service work is to be carried
out at a qualified specialist workshop.
Service products and filling capacities211
>> Technical data.
Z