check engine MERCEDES-BENZ CLA 2017 User Guide

Braking assistance appropriate to the situation
can also detect stationary objects, up to vehicle
speeds of around 44 mph 70 km/h. X
Keep the brake pedal depressed until the
emergency braking situation is over.
ABS prevents the wheels from locking.
The brakes will work normally again if: R
you release the brake pedal. R
there is no longer any danger of a collision. R
no obstacle is detected in front of your vehi-
cle.
Braking assistance appropriate to the situation
is then deactivated.
Important safety notes
i Observe the "Important safety notes" sec-
tion for driving safety systems ( Y
page 60).
G WARNING
Adaptive Brake Assist does not react: R
to people or animals R
to oncoming vehicles R
to crossing traffic R
when cornering
As a result, Adaptive Brake Assist may not
intervene in all critical conditions. There is a
risk of an accident.
Always pay careful attention to the traffic sit-
uation and be ready to brake.
G WARNING
Adaptive Brake Assist cannot always clearly
identify objects and complex traffic situa-
tions.
In such cases, Adaptive Brake Assist might: R
intervene unnecessarily R
not intervene
There is a risk of an accident.
Always pay careful attention to the traffic sit-
uation and be ready to brake. Terminate the
intervention in a non-critical driving situation.
Due to the nature of the system, complex but
non-critical driving conditions may also cause
Active Brake Assist to intervene.
Even if Active Brake Assist is not available due to
a malfunction in the radar sensor system, the brake system is still available with full brake
boosting effect and BAS.
ESP ®
(Electronic Stability Program)
General notes
i Observe the "Important safety notes" sec-
tion ( Y
page 60).
ESP ®
monitors driving stability and traction, i.e.
power transmission between the tires and the
road surface.
If ESP ®
detects that the vehicle is deviating from
the direction desired by the driver, one or more
wheels are braked to stabilize the vehicle. The
engine output is also modified to keep the vehi-
cle on the desired course within physical limits.
ESP ®
assists the driver when pulling away on
wet or slippery roads. ESP ®
can also stabilize
the vehicle during braking.
ETS/4ETS (Electronic Traction System)
i Observe the "Important safety notes" sec-
tion ( Y
page 60).
ETS traction control is part of ESP ®
. On vehicles
with 4MATIC, 4ETS is part of ESP ®
.
Traction control brakes the drive wheels indi-
vidually if they spin. This enables you to pull
away and accelerate on slippery surfaces, for
example if the road surface is slippery on one
side. In addition, more drive torque is transfer-
red to the wheel or wheels with traction.
Traction control remains active, even if you
deactivate ESP ®
.
Important safety notes
i Observe the "Important safety notes" sec-
tion ( Y
page 60).
G WARNING
If ESP ®
is malfunctioning, ESP ®
is unable to
stabilize the vehicle. Additionally, further driv-
ing safety systems are deactivated. This
increases the risk of skidding and an accident.
Drive on carefully. Have ESP ®
checked at a
qualified specialist workshop.Driving safety systems 63
Safety Z

Problem
Possible causes/consequences and P Solutions
KEYLESS-GO is malfunctioning. X
Lock/unlock the vehicle using the remote control function of the
SmartKey. X
Have the vehicle and SmartKey checked at a qualified specialist
workshop.
If the vehicle can also not be locked/unlocked using the remote con-
trol function: X
Unlock ( Y
page 76) or lock ( Y
page 76) the vehicle using the
mechanical key. X
Have the vehicle and SmartKey checked at a qualified specialist
workshop.
The engine cannot be
started using the Smart-
Key. The on-board voltage is too low. X
Switch off non-essential consumers, e.g. seat heating or interior
lighting, and try to start the engine again.
If this does not work: X
Check the starter battery and charge it if necessary ( Y
page 273).
or X
Jump-start the vehicle ( Y
page 273).
or X
Consult a qualified specialist workshop.
The engine cannot be
started using the Start/
Stop button. The Smart-
Key is in the vehicle. The vehicle is locked. X
Unlock the vehicle and try to start the vehicle again.
The SmartKey battery is discharged or nearly discharged. X
Check the SmartKey battery ( Y
page 72) and replace it if necessary
( Y
page 72).
If this does not work: X
Start your vehicle with the SmartKey in the ignition lock.
There is interference from a powerful source of radio waves. X
Start your vehicle with the SmartKey in the ignition lock.
You have lost a Smart-
Key. X
Have the SmartKey deactivated at a qualified specialist workshop. X
Report the loss immediately to the vehicle insurers. X
If necessary, have the locks changed as well.
You have lost the
mechanical key. X
Report the loss immediately to the vehicle insurers. X
If necessary, have the locks changed as well.74
SmartKey
Opening and closing

X
Press the locking button on the driver’s door
( Y
page 75). X
Check whether the locking knobs on the
front-passenger door and the rear doors are
still visible. Press down the locking knobs by
hand, if necessary. X
Close the driver's door. X
Take the mechanical key out of the SmartKey
( Y
page 71). X
Insert the mechanical key into the lock of the
driver's door as far as it will go.
X
Turn the mechanical key clockwise as far as it
will go to position G .X
Turn the mechanical key back and remove it. X
Make sure that the doors and the trunk lid are
locked. X
Insert mechanical key into the SmartKey
( Y
page 71).
i If you lock the vehicle as described above,
the fuel filler flap is not locked. The anti-theft
alarm system is not armed.
Trunk
Important safety notes
G WARNING
Combustion engines emit poisonous exhaust
gases such as carbon monoxide. Exhaust
gases can enter the vehicle interior if the
trunk lid is open when the engine is running,
especially if the vehicle is in motion. There is a
risk of poisoning.
Always switch off the engine before opening
the trunk lid. Never drive with the trunk lid
open. G WARNING
If objects, luggage or loads are not secured or
not secured sufficiently, they could slip, tip
over or be flung around and thereby hit vehicle
occupants. There is a risk of injury, particu-
larly in the event of sudden braking or a sud-
den change in direction.
Always store objects so that they cannot be
flung around. Secure objects, luggage or
loads against slipping or tipping before the
journey.
! The trunk lid swings upwards when opened.
Therefore, make sure that there is sufficient
clearance above the trunk lid.
The opening dimensions of the trunk lid can be
found in the "Vehicle data" section
( Y
page 314).
You should preferably place luggage or loads in
the trunk. Observe the loading guidelines
( Y
page 233).
Do not leave the SmartKey in the trunk. You
could otherwise lock yourself out.
The trunk lid can be: R
opened and closed manually from outside R
opened automatically from outside R
opened automatically from inside R
released with the emergency release from the
inside
Opening/closing from outside
Opening
X
Press the 6 button on the SmartKey. X
Pull handle C . X
Raise the trunk lid. Trunk 77
Opening and closing Z

! Do not warm up the engine with the vehicle
stationary. Drive off immediately. Avoid high
engine speeds and driving at full throttle until
the engine has reached its operating temper-
ature.
Only shift the automatic transmission to the
desired drive position when the vehicle is sta-
tionary.
Where possible, avoid spinning the drive
wheels when pulling away on slippery roads.
You could otherwise damage the drive train.
! Mercedes-AMG vehicles: avoid full-load
operation and engine speeds greater than
5000 rpm when the engine is cold. This helps
to protect the engine and avoids uncomfort-
able driving.
SmartKey positions
SmartKey
Z
To remove the SmartKey
(shift the transmission to position P )G
Power supply for some consumers, such as
the windshield wipersH
Ignition (power supply for all consumers)
and drive position
I
To start the engine
i The SmartKey can be turned in the ignition
lock even if it is not the correct SmartKey for
the vehicle. The ignition is not switched on.
The engine cannot be started. Start/Stop button General notes Vehicles with KEYLESS-GO are equipped with
SmartKeys featuring the integrated KEYLESS-
GO function and a detachable Start/Stop but-
ton.
A check which periodically establishes a radio
connection between the vehicle and the Smart-
Key determines whether a valid SmartKey is in
the vehicle. This occurs, for example, when
starting the engine.
When you insert the Start/Stop button into the
ignition lock, the system needs approximately
two seconds recognition time. You can then use
the Start/Stop button.
Pressing the Start/Stop button several times in
succession corresponds to the different Smart-
Key positions in the ignition lock. This is only the
case if you are not depressing the brake pedal.
If you depress the brake pedal and press the
Start/Stop button, the engine starts immedi-
ately.
To start the vehicle without actively using the
SmartKey: R
the Start/Stop button must be inserted in the
ignition lock. R
the SmartKey must be in the vehicle. R
the vehicle must not be locked with the
SmartKey or KEYLESS-GO ( Y
page 70)
Do not keep the KEYLESS-GO key: R
with electronic devices, e.g. a mobile phone
or another SmartKey. R
with metallic objects, e.g. coins or metal foil. R
inside metallic objects, e.g. a metal case
This can affect the functionality of KEYLESS-GO.
If you lock the vehicle with the SmartKey remote
control or with KEYLESS-GO, after a short time: R
you will not be able to switch on the ignition
with the Start/Stop button. R
you will no longer be able to start the engine
with the Start/Stop button until the vehicle is
unlocked again
If you lock the vehicle centrally using the button
on the front door ( Y
page 75), you can continue
to start the engine with the Start/Stop button.
The engine can be switched off while the vehicle
is in motion by pressing and holding the Start/
Stop button for three seconds. This function Driving 121
Driving and parking Z

G WARNING
Flammable materials introduced through
environmental influence or by animals can
ignite if in contact with the exhaust system or
parts of the engine that heat up. There is a risk
of fire.
Carry out regular checks to make sure that
there are no flammable foreign materials in
the engine compartment or in the exhaust
system.
General notes During a cold start, the engine runs at higher
speeds to enable the catalytic converter to
reach its operating temperature. The sound of
the engine may change during this time.
Automatic transmission X
Shift the transmission to position P
( Y
page 129).
The transmission position display in the mul-
tifunction display shows P ( Y
page 129).
i You can start the engine in transmission
position P and N .
Starting procedure with the SmartKey To start the engine using the SmartKey instead
of the Start/Stop button, pull the Start/Stop
button out of the ignition lock. X
Turn the SmartKey to position 3 in the ignition
lock and release it as soon as the engine is
running ( Y
page 121).
Starting procedure with the Start/Stop
button The Start/Stop button can be used to start the
vehicle manually without inserting the SmartKey
into the ignition lock. The Start/Stop button
must be inserted in the ignition lock and the
SmartKey must be in the vehicle. This mode for
starting the engine operates independently of
the ECO start/stop automatic engine start func-
tion.
You can start the engine if a valid SmartKey is in
the vehicle. Switch off the engine and always
take the SmartKey with you when leaving the vehicle, even if you only leave it for a short time.
Pay attention to the important safety notes. X
Depress the brake pedal and keep it
depressed. X
Press the Start/Stop button once
( Y
page 121).
The engine starts.
Starting procedure via smartphone Observe the important safety notes on starting
the engine ( Y
page 122).
You can also start your engine via your smart-
phone from outside the vehicle. In this case, the
previously selected climate control setting is
activated. In this way you can cool or heat the
interior of the vehicle before starting the jour-
ney.
Only start the engine via your smartphone if it is
safe to start and run the engine where your vehi-
cle is parked.
Observe the legal stipulations in the area where
your vehicle is parked. Engine start via smart-
phone may be limited to certain countries or
regions.
You can execute a maximum of two consecutive
starting attempts via your smartphone. If you
insert the SmartKey into the ignition lock, you
can carry out two more starting attempts.
Once you have started the engine, you can
switch the engine off via your smartphone at any
time.
You can only start the engine via your smart-
phone if: R
the SmartKey is in the ignition lock R
park position P is selected R
the accelerator pedal is not depressed R
the anti-theft alarm system is not activated R
the panic alarm is not activated R
the hazard warning lamps are switched off R
the hood is closed. R
the doors are closed and locked R
the windows and sliding sunroof are closed
Also make sure that: R
the fuel tank is sufficiently filled R
the starter battery is sufficiently charged
G WARNING
Limbs could be crushed or trapped if the
engine is started unintentionally during ser- Driving 123
Driving and parking Z

Problem
Possible causes/consequences and P Solutions
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 273).
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
Allow the starter motor to cool down for approximately two minutes. X
Try to start the engine again.
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 warning
lamp may also be on and
a warning tone may
sound. 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 257). Observe the warning notes
as you do so and add coolant if necessary.
DYNAMIC SELECT button (all vehicles
except Mercedes-AMG vehicles) Use the DYNAMIC SELECT button to change the
drive program. Depending on the drive program
selected the following vehicle characteristics
will change: R
the drive (engine and transmission manage-
ment) R
the suspension (vehicles with damping sys-
tem or AMG adaptive sport suspension sys-
tem) R
the steering. R
the availability of the ECO start/stop function R
the climate control
Each time you start the engine with the Smart-
Key or the Start/Stop button, drive program C is
activated. For further information about starting
the engine, see ( Y
page 122). X
Press DYNAMIC SELECT button C as many
times as necessary until the desired drive
program is selected.
The selected drive program appears in the
multifunction display. After five seconds the
display goes out and the status icon of the
selected drive program appears.DYNAMIC SELECT button (all vehicles except Mercedes-AMG vehicles) 127
Driving and parking Z

Transmission positions E Park position
This prevents the vehicle from rolling
away when stopped.
Only shift the transmission into posi-
tion P when the vehicle is stationary.
The parking lock should not be used
as a brake when parking. Always
apply the electronic parking brake in
addition to the parking lock in order
to secure the vehicle.
If the vehicle electronics are malfunc-
tioning, the transmission may be
locked in position P . Have the vehicle
electronics checked immediately at a
qualified specialist workshop.
Park position P is automatically
engaged if: R
you switch off the engine using the
SmartKey and remove the Smart-
Key R
you switch off the engine using the
SmartKey or using the Start/Stop
button and open the driver's door
or front-passenger door R
the driver's door is opened when
the vehicle is stationary or driving
at very low speed and the trans-
mission is in position D or R
F Reverse gear
Only shift the transmission into posi-
tion R when the vehicle is stationary. D Neutral
Do not shift the transmission to N
while driving. Otherwise, the auto-
matic transmission could be dam-
aged.
No power is transmitted from the
engine to the drive wheels.
Releasing the brakes will allow you to
move the vehicle freely, e.g. to push
it or tow it.
If ESP ®
is deactivated or faulty: shift
the transmission to position N if the
vehicle is in danger of skidding, e.g.
on icy roads.
If you switch the engine off with the
transmission in position R or D , the
automatic transmission shifts to N
automatically.
! Rolling in neutral N can damage
the drive train.
: Drive
The automatic transmission changes
gear automatically. All forward gears
are available.
Driving tips
Changing gear The automatic transmission shifts to the indi-
vidual gears automatically when it is in trans-
mission position D . This automatic gear shifting
behavior is determined by: R
the selected drive program R
the position of the accelerator pedal R
the road speed
Accelerator pedal position Your style of driving influences how the auto-
matic transmission shifts gear: R
little throttle: early upshifts R
more throttle: late upshifts132
Automatic transmission
Driving an d parking

Before the engine speed reaches the red area,
an upshift indicator will be shown in the multi-
function display. X
Shift to recommended gear C when mes-
sage D is shown in the multifunction display.
Kickdown X
For maximum acceleration, depress the
accelerator pedal beyond the pressure point.
The automatic transmission shifts to a lower
gear depending on the engine speed. X
Shift back up once the desired speed is
reached. During kickdown, you cannot shift gears using
the steering wheel paddle shifters.
If you apply full throttle, the automatic trans-
mission shifts up to the next gear when the
maximum engine speed is reached. This pre-
vents the engine from overrevving.
Mercedes-AMG vehicles: it is only possible to
use kickdown in temporary manual drive pro-
gram M . When manual drive program M is per-
manently activated, kickdown is not possible.
Problems with the transmission Problem
Possible causes/consequences and P Solutions
The transmission has
problems shifting gear. The transmission is losing oil. X
Have the transmission checked at a qualified specialist workshop
immediately.
The acceleration ability
is deteriorating.
The transmission no lon-
ger shifts into all of the
gears.
Reverse gear can no lon-
ger be engaged. The transmission is in emergency mode. X
Stop the vehicle. X
Shift the transmission to position P .X
Switch off the engine. X
Wait at least ten seconds before restarting the engine. X
Shift the transmission to position D .X
Have the transmission checked at a qualified specialist workshop
immediately.
Refueling
Important safety notes
G WARNING
Fuel is highly flammable. If you handle fuel
incorrectly, there is a risk of fire and explo-
sion. You must avoid fire, open flames, creating
sparks and smoking. Switch off the engine
and, if applicable, the auxiliary heating before
refueling.
G WARNING
Fuel is poisonous and hazardous to health.
There is a risk of injury. Refueling 137
Driving and parking Z

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. 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.
! As the ESP ®
system operates automatically,
the engine and the ignition must be switched
off (the SmartKey must be in position 0 or 1 in
the ignition lock) if: R
the electric parking brake is tested on a
brake dynamometer (for a maximum of
ten seconds) R
the vehicle is towed with the front axle
raised.
Braking triggered automatically by ESP ®
may
seriously damage 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 in t ervals.
You can find a description of Brake Assist (BAS)
on ( Y
page 60).
Mercedes-Benz recommends that you only have
brake pads/linings installed on your vehicle
which have been approved for Mercedes-Benz
vehicles or which correspond to an equivalent
quality standard. Brake pads/linings which have
not been approved for Mercedes-Benz vehicles
or which are not of an equivalent quality could
affect your vehicle's operating safety.
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.
Checking brake lining thickness You can measure the break pad/lining thick-
ness using a test gage. Color-coding (green or
red) on the test gage allows you to determine
whether the brake pad/lining thickness is still
sufficient. The test gage is in the vehicle docu-
ment wallet in the glove box.
Front wheel146
Driving tips
Driving and parking

Important safety notes
G WARNIN G
If you operate information systems and com-
munication equipmen t integrate d in th e vehi-
cle while driving , you will be distracte d from
traffic conditions. You could also lose control
of th e vehicle. Ther e is a ris k of an accident.
Only operate th e equipmen t when th e traffic
situation permits. If you are no t sur e that this
is possible , park th e vehicl e payin g attention
to traffic condition s and operate th e equip-
men t when th e vehicl e is stationary.
You must observ e th e legal requirements for th e
country in whic h you are currentl y driving when
operating th e on-board computer.
G WARNIN G
If th e instrumen t cluste r has faile d or mal-
functioned, you may no t recognize function
restriction s in systems relevan t to safety. The
operating safet y of your vehicl e may be
impaired . Ther e is a ris k of an accident.
Drive on carefully. Hav e th e vehicl e checke d
at a qualified specialist workshop immedi-
ately.
The on-board computer only shows message s or
warning s from certain systems in th e multifunc-
tion display. You should therefor e mak e sur e
your vehicl e is operating safely at all times .
If th e operating safet y of your vehicl e is
impaired , pull ove r as soo n as it is saf e to do so.
Contac t a qualified specialist workshop.
Fo r an overview, see th e instrumen t panel illus-
tration ( Y
page 32).
Displays and operation
Instrument cluster lighting
The ligh t sensor in th e instrumen t cluste r auto -
matically control s th e brightness of th e multi-
function display. In daylight, th e displays in th e
instrumen t cluste r are no t illuminated.
The lighting in th e instrumen t cluster, in th e dis-
plays and th e control s in th e vehicl e interior can
be adjusted usin g th e brightness control knob. The brightness control knob is locate d on th e
botto m lef t of th e instrumen t cluste r
( Y
page 32). X
Turn th e brightness control knob clockwise or
counter-clockwise.
If th e ligh t switch is set to th e X , ` or
X position , th e brightness is dependen t
upon th e brightness of th e ambien t light.
Speedometer with segments The speedometer is divided int o segments on
vehicles wit h Distanc e Pilot DISTRONIC.
The segments in th e speedometer indicat e
whic h spee d range is available. R
Distanc e Pilot DISTRONI C is activated
( Y
page 150):
On e or two segments in th e set spee d range
ligh t up. R
Distanc e Pilot DISTRONI C detects a vehicl e in
fron t moving mor e slowly than th e store d
speed:
The segments between th e spee d of th e vehi-
cle in fron t and th e store d spee d ligh t up.
Tachometer
! Do no t driv e in th e overrevving range, as this
could damag e th e engine.
The red ban d in th e tachometer indicates th e
engine's overrevving range.
The engin e is limite d within a range to protect
th e engin e when th e red ban d is reached.
Outside temperature display You should pay special attention to road condi-
tion s when temperatures are aroun d freezing
point.
Bea r in min d that th e outside temperature dis-
play indicates th e temperature measured and
does no t record th e road temperature.
The outside temperature display is in th e multi-
function display ( Y
page 176).
Ther e is a short delay before a chang e in outside
temperature appear s in th e multifunction dis-
play.174
Displays and operation
On-board computer and displays