2018 MERCEDES-BENZ CLS ECU

Locking/unlocking the driver's door
with the mechanical key
i If you want to centrally lock the vehicle using
the mechanical key, begin by pressing the
locking button for the interior locking mech-
anism while the driver's door is open. Then
lock the driver's door using the mechanical
key.
X
To unlock: turn the mechanical key counter-
clockwise as far as it will go to position G .X
To lock: turn the mechanical key clockwise as
far as it will go to position G .
If you use the mechanical key to unlock and
open the driver's door, the anti-theft alarm sys-
tem will be triggered. Switch off the alarm
( Y
page 75).
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 328).
You should preferably place luggage or loads in
the trunk. Observe the loading guidelines
( Y
page 242).
Do not leave the SmartKey in the trunk. You
could otherwise lock yourself out.
Vehicles without the trunk lid remote clos-
ing feature: the trunk lid can be: R
opened and closed manually from outside R
opened automatically from outside R
opened automatically from inside R
locked separately R
opened with the emergency release button R
unlocked with the mechanical key
Vehicles with the trunk lid remote closing
feature: the trunk lid can be: R
opened and closed manually from outside R
opened/closed automatically from outside R
opened/closed automatically from inside R
locked separately R
opened with the emergency release button R
unlocked with the mechanical key
Trunk lid reversing feature The trunk lid is equipped with an automatic
reversing feature. It reacts if a solid object
obstructs or restricts the trunk lid during the
closing procedure. The trunk lid opens again
automatically. The automatic reversing feature
is only an aid and is not a substitute for your
attentiveness when closing the trunk. Trunk 83
Opening and closing Z

It is only possible to shift the transmission from
position P to the desired position if you depress
the brake pedal. If the brake pedal is not
depressed, the DIRECT SELECT lever can still be
moved but the parking lock remains engaged.
i Upshifts take place at higher engine speeds
after a cold start. This helps the catalytic con-
verter to reach its operating temperature
more quickly.
Hill start assist Hill start assist helps you when pulling away for-
wards or in reverse on an uphill gradient. It holds
the vehicle for a short time after you have
removed your foot from the brake pedal. This
gives you enough time to move your foot from
the brake pedal to the accelerator pedal and to
depress it before the vehicle begins to roll.
G WARNING
After a short time, hill start assist will no lon-
ger brake your vehicle and it could roll away.
There is a risk of an accident and injury.
Therefore, quickly move your foot from the
brake pedal to the accelerator pedal. Never
leave the vehicle when it is held by hill start
assist.
Hill start assist is not active if: R
you are pulling away on a level road or on a
downhill gradient. R
the transmission is in position N .R
the parking brake is applied. R
ESP ®
is malfunctioning.
ECO start/stop function
Introduction The ECO start/stop function switches the
engine off automatically if the vehicle is stopped
under certain conditions.
The engine starts automatically when the driver
wants to pull away again. The ECO start/stop
function thereby helps you to reduce the fuel
consumption and emissions of your vehicle. Important safety notes
G WARNING
If the engine is switched off automatically and
you exit the vehicle, the engine is restarted
automatically. The vehicle may begin moving.
There is a risk of accident and injury.
If you wish to exit the vehicle, always turn off
the ignition and secure the vehicle against
rolling away.
General notes
C
ECO start/stop display
The ECO start/stop function is activated when
you start the engine.
If the engine has been switched off automati-
cally by the ECO start/stop function, the

R
the system detects that the windshield is not
fogged up when the air-conditioning system is
switched on R
the hood is closed R
the driver's door is closed and the driver's
seat belt is fastened
i All of the vehicle's systems remain active
when the engine is stopped automatically.
i The HOLD function can also be activated if
the engine has been switched off automati-
cally. It is then not necessary to continue
applying the brakes during the automatic stop
phase. When you depress the accelerator
pedal, the engine starts automatically and the
braking effect of the HOLD function is deac-
tivated.
Automatic engine switch-off can take place a
maximum of four times in a row (initial stop, then
three subsequent stops).
Mercedes-AMG vehicles: the number of con-
secutive automatic engine switch-offs is unlimi-
ted.
All other models: automatic engine switch-off
can take place a maximum of four times in a row
(initial switch-off, then three subsequent switch-
offs).
Automatic engine start The engine starts automatically if: R
you switch off the ECO start/stop function by
pressing the ECO button R
in transmission position D or N the brake
pedal is released and the HOLD function is not
active R
you depress the accelerator pedal R
you engage reverse gear RR
you move the transmission out of position PR
you switch to drive program S , S+ or M
(Mercedes-AMG vehicles) R
you unfasten your seat belt or open the driv-
er's door R
the vehicle starts to roll R
the brake system requires this R
the temperature in the vehicle interior devi-
ates from the set range R
the system detects moisture on the wind-
shield when the air-conditioning system is
switched on R
the battery's condition of charge is too low i Shifting the transmission to position P does
not start the engine.
Deactivating or activating the ECO
start/stop function Mercedes-AMG vehicles X
To deactivate: in drive program C , press ECO
button C .
or X
Switch to drive program S , S+ or M
( Y
page 134).
Indicator lamp D goes out.X
To activate: press ECO button C .
Indicator lamp D lights up.
If drive program S , S+ or M is active, the auto-
matic transmission switches to drive program
C .
If indicator lamp D is off, the ECO start/stop
function has been deactivated manually or as
the result of a malfunction. The engine will then
not be switched off automatically when the vehi-
cle stops.
All other models Driving 127
Dr ivi ng an d parking Z

X
Vehicles with KEYLESS-GO: remove the
Start/Stop button from the ignition lock. X
Insert the Smartkey into the ignition lock. X
All vehicles: switch the ignition on.X
Depress the brake pedal and keep it
depressed. X
Shift to neutral N .X
Release the brake pedal. X
Release the parking brake. X
Switch off the ignition and leave the Smartkey
in the ignition lock.
Engaging drive position D X
If the transmission is in position R or N : push
the DIRECT SELECT lever down past the first
point of resistance. X
If the transmission is in position P : depress
the brake pedal and push the DIRECT SELECT
lever down past the first point of resistance. Transmission positions E Park position
Only shift the transmission into posi-
tion P when the vehicle is stationary
( Y
page 142). The parking lock
should not be used as a brake when
parking. Always apply the 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.132
Automatic transmission
Driving and parking

Problem
Possible causes/consequences and P Solutions
The SmartKey battery is discharged or nearly discharged. X
Unlock the vehicle using the mechanical key ( Y
page 78).X
Open the trunk lid. X
Manually unlock the fuel filler flap using the emergency release
( Y
page 140).
The fuel filler flap is unlocked, but the opening mechanism is jammed. X
Consult a qualified specialist workshop.
Parking
Important safety notes
G WARNING
Flammable material such as leaves, grass or
twigs may ignite if they come into contact with
hot parts of the exhaust system or exhaust
gas flow. There is a risk of fire.
Park the vehicle so that no flammable mate-
rials come into contact with parts of the vehi-
cle which are hot. Take particular care not to
park on dry grassland or harvested grain
fields.
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.
! Always secure the vehicle correctly against
rolling away. Otherwise, the vehicle or its driv-
etrain could be damaged. To ensure that the vehicle is secured against
rolling away unintentionally: R
the parking brake must be applied. R
the transmission must be in position P and the
Smartkey must be removed from the ignition
lock. R
the front wheels must be turned towards the
curb on steep uphill or downhill gradients.
Switching off the engine
Important safety notes
G WARNING
The automatic transmission switches to neu-
tral position N when you switch off the engine.
The vehicle may roll away. There is a risk of an
accident.
After switching off the engine, always switch
to parking position P . Prevent the parked vehi-
cle from rolling away by applying the parking
brake.
Vehicles with automatic transmission X
Apply the parking brake firmly. X
All vehicles (except Mercedes-AMG vehi-
cles): shift the transmission to position P .Parking 141
Driving and parking Z

between your vehicle and the vehicle in front
becomes too small.
i When you change lanes, DISTRONIC PLUS
monitors the left lane on left-hand-drive vehi-
cles or the right lane on right-hand-drive vehi-
cles.
Stopping
G WARNING
When leaving the vehicle, even if it is braked
only by DISTRONIC PLUS, it could roll away if: R
there is a malfunction in the system or in
the voltage supply. R
DISTRONIC PLUS has been deactivated
with the cruise control lever, e.g. by a vehi-
cle occupant or from outside the vehicle. R
the electrical system in the engine com-
partment, the battery or the fuses have
been tampered with. R
the battery is disconnected. R
the accelerator pedal has been depressed,
e.g. by a vehicle occupant.
There is a risk of an accident.
If you wish to exit the vehicle, always turn off
DISTRONIC PLUS and secure the vehicle
against rolling away.
For further information on deactivating
DISTRONIC PLUS ( Y
page 155).
If DISTRONIC PLUS detects that the vehicle in
front has stopped, it will cause your vehicle to
brake and come to a halt.
Once your vehicle is stationary, it remains sta-
tionary and you do not need to depress the
brake.
Depending on the specified minimum distance,
your vehicle will come to a standstill at a suffi-
cient distance behind the vehicle in front. The
specified minimum distance is set using the
control on the cruise control lever.
When DISTRONIC PLUS is activated, the trans-
mission is shifted automatically to position P if:R
the driver's door is open and the driver's seat
belt is unfastened. R
the engine is switched off, unless it is auto-
matically switched off by the ECO start/stop
function. R
a system malfunction occurs. R
the power supply is not sufficient.
Setting a speed X
Press the cruise control lever up C for a
higher speed or down D for a lower speed.X
To adjust the set speed in 1 mph incre-
ments (1 km/h increments): briefly move
the cruise control lever up C or down D to
the pressure point.
Every time the cruise control lever is pressed
up C or down D , the last speed stored is
increased or reduced. X
To adjust the set speed in 5 mph incre-
ments (1 0 km/h increments): briefly move
the cruise control lever up C or down D
beyond the pressure point.
Every time the cruise control lever is pressed
up C or down D , the last speed stored is
increased or reduced.
i If you accelerate to overtake, DISTRONIC
PLUS adjusts the vehicle's speed to the last
speed stored after you have finished overtak-
ing.
Setting a specified minimum distance You can set the specified minimum distance for
DISTRONIC PLUS by varying the time span
between one and two seconds. With this func-
tion, you can set the minimum distance that
DISTRONIC PLUS keeps to the vehicle in front,
dependent on vehicle speed. You can see this
distance in the multifunction display
( Y
page 154).
i Make sure that you maintain a sufficient
distance to the vehicle in front and comply
with the minimum distance as required by
law. Adjust the distance to the vehicle in front
if necessary.Driving systems 153
Driving and parking Z

still not started to steer and have not taken hold
of the steering wheel after five seconds at the
latest, a warning tone also sounds to remind you
to take control of the vehicle. Steering Assist
and Stop&Go Pilot are switched to passive.
DISTRONIC PLUS remains active.
Activating Steering Assist and Stop&Go
Pilot X
Activate the DISTRONIC PLUS with Steering
Assist and Stop&Go Pilot function using the
on-board computer ( Y
page 196).
The DTR+: Steering Assistant On mes-
sage appears in the multifunction display.
Steering Assist and Stop&Go Pilot are active.
Information in the multifunction display
If Steering Assist and Stop&Go Pilot are activa-
ted but not ready for a steering intervention,
steering wheel symbol C appears in gray. If the
system provides you with support by means of
steering interventions, symbol C is shown in
green.
Deactivating Steering Assist and Stop&Go
Pilot X
Deactivate the DISTRONIC PLUS with Steer-
ing Assist and Stop&Go Pilot function using
the on-board computer ( Y
page 196).
The DTR+: Steering Assistant Off mes-
sage appears in the multifunction display.
Steering Assist and Stop&Go Pilot are deac-
tivated.
When DISTRONIC PLUS is deactivated or not
available, Steering Assist and Stop&Go Pilot are
deactivated automatically. HOLD function
General notes The HOLD function can assist the driver in the
following situations: R
when pulling away, especially on steep slopes R
when maneuvering on steep slopes R
when waiting in traffic
The vehicle is kept stationary without the driver
having to depress the brake pedal.
The braking effect is canceled and the HOLD
function deactivated when you depress the
accelerator pedal to pull away.
Important safety notes
G WARNING
When leaving the vehicle, it can still roll away
despite being braked by the HOLD function if: R
there is a malfunction in the system or in
the voltage supply. R
the HOLD function has been deactivated by
pressing the accelerator pedal or the brake
pedal, e.g. by a vehicle occupant. R
the electrical system in the engine com-
partment, the battery or the fuses have
been tampered with. R
the battery is disconnected
There is a risk of an accident.
If you wish to exit the vehicle, always turn off
the HOLD function and secure the vehicle
against rolling away.
! When DISTRONIC PLUS or the HOLD func-
tion is activated, the vehicle brakes automat-
ically in certain situations.
To avoid damage to the vehicle, deactivate
DISTRONIC PLUS and the HOLD function in
the following or similar situations: R
when towing the vehicle R
in the car washDriving systems 157
Driving and parking Z

Display messages
Possible causes/consequences and P Solutions
' (US A only)
M (Canada only)
Check Brake Fluid
Level There is no t enough brak e fluid in th e brak e fluid reservoir .
In addition , th e ' (US A only) or M (Canada only) warning lamp
lights up in th e instrumen t cluste r and a warning tone sounds.
G WARNIN G
The braking effec t may be impaired.
There is a ris k of an accident.X
Pull ove r and stop th e vehicl e safely as soo n as possible, payin g
attention to roa d and traffic conditions. Do no t continu e drivin g
under any circumstances. X
Secur e th e vehicl e against rollin g away ( Y
page 141).X
Consult a qualified specialist workshop .X
Do no t add brak e fluid . This does no t correc t th e malfunction .
& Check Brake Pad Wea r The brak e pads/linings hav e reached their wear limit.X
Visit a qualified specialist workshop .
S mbrace Inoperative On e or mor e main features of th e mbrace system are malfunctioning .X
Visit a qualified specialist workshop .
Collision Preven ‐
tio n Assist Plu s
Currently Unavaila‐
ble See Operator' s
Manual COLLISION PREVENTION ASSIST PLU S is temporarily no t operational.
Possibl e causes are: R
th e radar sensor system is temporarily inoperative, e.g. due to elec -
tromagneti c radiation emitted by nearby TV or radi o station s or
other source s of electromagneti c radiationR
th e system is outside th e operating temperature rangeR
th e on-boar d voltag e is to o low.
Whe n th e causes state d abov e no longer apply, th e display message
disappears.
COLLISION PREVENTION ASSIST PLU S is operational again .
If th e display message does no t disappear :X
Pull ove r and stop th e vehicl e safely as soo n as possible, payin g
attention to roa d and traffic conditions.X
Secur e th e vehicl e against rollin g away ( Y
page 141).X
Restart th e engine.
Collision Preven ‐
tio n Assist Plu s
Inoperative COLLISION PREVENTION ASSIST PLU S is temporarily inoperative due
to a malfunction . Adaptive Brake Assis t may also hav e failed.X
Visit a qualified specialist workshop .
PRE-SAFE
Inoperative See
Operator' s Manual Importan t function s of PRE-SAF E ®
hav e failed. Al l other occupant
safet y systems , e.g. air bags , remain available.X
Visit a qualified specialist workshop .206
Display messages
On-board computer and displays