engine MERCEDES-BENZ CLS-Class 2012 W218 Service Manual

Useful information
i This Operator's Manual describes all
models and all standard and optional
equipment of your vehicle available at the
time of publication of the Operator's
Manual. Country-specific differences are
possible. Please note that your vehicle may
not be equipped with all features
described. This also applies to safety-
related systems and functions.
i Please read the information on qualified
specialist workshops ( Y page 22).
Driving
Important safety notes
GWARNING
Make sure absolutely no objects are
obstructing the pedals' range of movement.
Keep the driver's footwell clear of all
obstacles. If there are any floormats or
carpets in the footwell, make sure the pedals
still have sufficient clearance.
During sudden driving or braking maneuvers
the objects could get caught between the
pedals. You could then no longer brake or
accelerate. This could lead to accidents and
injury.
GWARNING
On slippery road surfaces, never downshift in
order to obtain braking action. This could
result in drive wheel slip and reduced vehicle
control. Your vehicle's ABS will not prevent
this type of loss of control.
GWARNING
It is dangerous to shift the automatic
transmission out of parking position P or
neutral position N if the engine speed is
higher than idle speed. If your foot is not firmly
on the brake pedal, the vehicle could
accelerate quickly forward or in reverse. You
could lose control of the vehicle and hit
someone or something. Only shift into gear
when the engine is idling normally and when
your right foot is firmly on the brake pedal.
! Warm up the engine quickly. Do not use
the engine's full performance until it has
reached operating temperature.
Only shift the automatic transmission to
the desired drive position when the vehicle
is stationary.
Where possible, avoid spinning the drive
wheels when pulling away on slippery
roads. You could otherwise damage the
drive train.
! AMG vehicles: at low engine oil
temperatures (below 68 ‡ (+20 †), the
maximum engine speed is restricted in
order to protect the engine. To protect the
engine and maintain smooth engine
operation, avoid driving at full throttle when
the engine is cold.
SmartKey positions
SmartKey
gTo remove the SmartKey(shift the transmission to position P)1Power supply for some consumers, such
as the windshield wipers2Ignition (power supply for all consumers)
and drive position3To start the engine
If the SmartKey is in position 0 in the ignition
lock for an extended period of time, it can no
132DrivingDriving and parking

longer be turned in the ignition lock. The
steering is then locked. To unlock, remove the
SmartKey and reinsert it into the ignition lock.
The steering is locked when you remove the
SmartKey from the ignition lock.
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.
KEYLESS-GO
General information
Vehicles with KEYLESS-GO are equipped with
a SmartKey featuring an integrated KEYLESS-
GO function and a detachable Start/Stop
button.
The Start/Stop button must be inserted into
the ignition lock and the SmartKey must be in
the vehicle.
Pressing the Start/Stop button several times
in succession corresponds to the different
SmartKey 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
immediately.
The Start/Stop button can be removed from
the ignition lock. Then, you can insert the
SmartKey into the ignition lock.
i You do not have to remove the Start/Stop
button from the ignition lock when you
leave the vehicle. However, you should
always take the SmartKey with you when
leaving the vehicle. The vehicle can be
started with the Start/Stop button and the
electrical equipment can be operated while
the SmartKey is in the vehicle.
:Start/Stop button;Ignition lockXInsert Start/Stop button : into ignition
lock ;.
i
When you insert Start/Stop button :
into ignition lock ;, the system requires a
detection time of approximately two
seconds before you can use Start/Stop
button :.
Start/Stop button
=USA only?Canada onlyXPosition 0: if Start/Stop button : has not
yet been pressed, this corresponds to the
SmartKey being removed from the ignition.XPosition 1: press Start/Stop button :.
You can now activate the windshield
wipers, for example.
i If you then open the driver's door when in
this position, the power supply is
deactivated.
Driving133Driving and parkingZ

XPosition 2 (ignition): press Start/Stop
button : twice.
i
If you press Start/Stop button : once
when in this position and the driver's door
is open, the power supply is deactivated
again.
As soon as the ignition is switched on, all the
indicator lamps in the instrument cluster light
up. If an indicator lamp does not go out after
the engine is started or if it lights up while the
vehicle is in motion, see ( Y page 243).
Starting the engine
Important safety notes
GWARNING
Inhalation of exhaust gas is hazardous to your
health. All exhaust gas contains carbon
monoxide (CO), and inhaling it can cause
unconsciousness and possible death.
Do not run the engine in confined areas (such
as a garage) which are not properly ventilated.
If you think that exhaust gas fumes are
entering the vehicle while driving, have the
cause determined and corrected
immediately. If you must drive under these
conditions, drive only with at least one
window fully open at all times.
! Do not depress the accelerator pedal
when starting the engine.
i The catalytic converter is preheated for
up to 30 seconds after a cold start. During
this time, the engine sound may be
different.
i The catalytic converter is preheated for
up to 30 seconds after a cold start. During
this time, the engine sound may be
different.
Automatic transmissionXShift the transmission to position P.
The transmission position display in the
multifunction display shows P.
i
You can also start the engine when the
transmission is in position N.
Starting procedure with the SmartKey
i To start the engine using the SmartKey
instead of KEYLESS-GO, pull the Start/
Stop button out of the ignition lock.
XTurn the SmartKey to position 3 in the
ignition lock (Y page 132) and release it as
soon as the engine is running.
Using KEYLESS-GO to start the engine
GWARNING
As long as the SmartKey is in your vehicle, the
vehicle can be started. Therefore, never leave
children unattended in the vehicle, as they
could otherwise accidentally start the engine.
When leaving the vehicle, always take the
SmartKey with you and lock the vehicle. Do
not leave children unattended in the vehicle,
or with access to an unlocked vehicle. A
child's unsupervised access to a vehicle could
result in an accident and/or serious personal
injury.
i 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 into
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 function.
XDepress the brake pedal and keep it
depressed.XPress the Start/Stop button ( Y page 133)
once.
The engine starts.134DrivingDriving and parking

Pulling away
Automatic transmissionGWARNING
It is dangerous to shift the automatic
transmission out of parking position P or
neutral position N if the engine speed is
higher than idle speed. If your foot is not firmly
on the brake pedal, the vehicle could
accelerate quickly forward or in reverse. You
could lose control of the vehicle and hit
someone or something. Only shift into gear
when the engine is idling normally and when
your right foot is firmly on the brake pedal.
i It is only possible to shift the transmission
from position P to the desired position if
you depress the brake pedal. Only then is
the parking lock released. If you do not
depress the brake pedal, you can move the
DIRECT SELECT lever but the parking lock
remains engaged.
XDepress the brake pedal and keep it
depressed.XShift the transmission to position D or R.XRelease the parking brake ( Y page 151).XRelease the brake pedal.XCarefully depress the accelerator pedal.
!
If a warning tone sounds and the
Release Park. Brake message appears
in the multifunction display, the parking
brake is still applied. Release the parking
brake.
i The vehicle locks centrally once you have
pulled away. The locking knobs in the doors
drop down.
You can open the doors from the inside at
any time.
You can also deactivate the automatic
locking feature ( Y page 211).
i Upshifts take place at higher engine
speeds after a cold start. This helps the
catalytic converter to reach its operating
temperature more quickly.
Hill start assist
Hill start assist helps you when pulling away
forwards 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 depress it before the vehicle begins to
roll.
GWARNING
Never leave the vehicle when it is held by hill
start assist. After approximately one second,
hill start assist will no longer brake your
vehicle and it could roll away.
XTake your foot off the brake pedal.
i Once you have taken your foot off the
brake pedal, the vehicle is held for around
one second.
XPull away.
Hill start assist will not function if:
R you are pulling away on a level road or a
downhill gradient.
R the transmission is in position N.
R the parking brake is applied.
R ESP ®
is malfunctioning.
ECO start/stop function
General information
The ECO start/stop function is only available
for the CLS 63 AMG.
The ECO start/stop function is only available
in drive program C.
The ECO start/stop function switches the
engine off automatically when the vehicle
stops moving.
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.
Driving135Driving and parkingZ

:ECO symbol;ECO start/stop display message
The ECO start/stop function is activated each
time the engine is switched on. If all the
requirements are fulfilled for automatic
engine switch-off ( Y page 136), green ECO
symbol : is shown in the multifunction
display and Stop/Start active ; appears.
If all the requirements are not fulfilled, ECO
symbol : is shown in yellow and Stop/
Start inactive ; appears.
If the ECO start/stop function is deactivated
( Y page 137), ECO symbol : is not shown.
GWARNING
If the engine is switched off and the ECO
symbol is shown in green in the multifunction
display, the engine has been switched off
automatically. All of the vehicle's systems
remain active. If you open the door, unfasten
your seat belt or remove your foot from the
brake pedal, the engine will automatically
start. The vehicle may begin moving. You
could suffer serious or even fatal injury or
cause an accident resulting in injury or death.
Never leave the vehicle while the ECO symbol
in the multifunction display is shown in green
or yellow. Always secure the vehicle against
rolling away before leaving it.
! Always switch the ignition off and take the
key with you when leaving the vehicle.
Automatic engine switch-off
The ECO start/stop function switches the
engine off automatically if the vehicle is
braked to a standstill and the brake remains
depressed with the transmission in position
D or N.
i
You can still activate the HOLD function
when the vehicle is stationary, even if the
engine has been switched off
automatically. 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 deactivated. Depress the
accelerator pedal carefully, as the engine
must be started first.
The engine is only switched off if:
R the outside temperature is within the range
which is suitable for the system.
R the engine is at normal operating
temperature.
R the set temperature for the vehicle interior
has been reached.
R the battery is sufficiently charged.
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 no engine relevant diagnostics are active.
R the front door is closed and the seat belt is
fastened.
Automatic engine start
The engine is started automatically if you:
R release the brake pedal when HOLD is not
activated and the transmission is in
position D or N
R shift the transmission to position R
R depress the accelerator pedal
R switch off the ECO start/stop function by
pressing the ECO button
R switch to drive program S, S+ or M
R unfasten your seat belt or open the driver's
door
The engine is also started automatically if:
R the vehicle starts to roll.
R the brake system requires this.
136DrivingDriving and parking

Rthe system detects moisture on the
windshield when the air-conditioning
system is switched on.
R the temperature in the vehicle interior
deviates from the set range.
R the charge level of the battery is too low.
Deactivating/activating the ECO start/
stop function
Example: ECO button
Deactivating
XPress button :.
or
XSwitch to drive program S, S+ or
M (Y page 143).
Indicator lamp ; on button :, the ECO
symbol and the Stop/Start active or
Stop/Start inactive message go out in
the multifunction display.
Activating
XPress button :.
or
XSwitch to drive program C(Y page 143).
Indicator lamp ; lights up. If all conditions
for automatic engine switch-off
( Y page 136) are fulfilled, the ECO symbol
is shown in green in the multifunction
display. In addition, the Stop/Start
active message appears in the
multifunction display. If not all conditions
have been fulfilled for automatic engine
switch-off ( Y page 136), the Stop/Start
inactive message is shown in themultifunction display and the ECO symbol
is shown in yellow.
i If you press button : while drive program
S , S+ or M is active, the automatic
transmission shifts to drive program C.
i If indicator lamp ; 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 vehicle stops.
i Every time you start the engine, the ECO
start/stop function is switched on and the
automatic transmission shifts to automatic
drive program C.
Driving137Driving and parkingZ

Problems with the engineProblemPossible causes/consequences and M SolutionsThe 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.XBefore attempting to start the engine again, turn the SmartKey
in the ignition back to position 0 or press the Start/Stop button
repeatedly until all indicator lamps in the instrument cluster go
out.XTry to start the engine again ( Y page 134). 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:
XConsult a qualified specialist workshop, e.g. an authorized
Mercedes-Benz Center.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.XJump-start the vehicle ( Y page 305).
If the engine does not start despite attempts to jump-start it:
XConsult a qualified specialist workshop, e.g. an authorized
Mercedes-Benz Center.The starter motor was exposed to a thermal load that was too high.XAllow the starter motor to cool down for approximately two
minutes.XTry to start the engine again.
If the engine still does not start:
XConsult a qualified specialist workshop, e.g. an authorized
Mercedes-Benz Center.138DrivingDriving and parking

ProblemPossible causes/consequences and M SolutionsThe engine is not
running smoothly and
is misfiring.There is a malfunction in the engine electronics or a mechanical
component of the engine management system.XOnly depress the accelerator pedal slightly.XHave the cause rectified immediately at a qualified specialist
workshop, e.g. an authorized Mercedes-Benz Center.
Otherwise, non-combusted fuel may get into the catalytic
converter and damage it.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.XStop as soon as possible and allow the engine and the coolant
to cool down.XCheck the coolant level ( Y page 282). Observe the warning
notes as you do so and add coolant if necessary.Automatic transmission
Important safety notes
GWARNING
It is dangerous to shift the automatic
transmission out of parking position P or
neutral position N if the engine speed is
higher than idle speed. If your foot is not firmly
on the brake pedal, the vehicle could
accelerate quickly forward or in reverse. You
could lose control of the vehicle and hit
someone or something. Only shift into gear
when the engine is idling normally and when
your right foot is firmly on the brake pedal.
GWARNING
Keep in mind that turning off the engine alone
only will shift the automatic transmission into
neutral position N automatically.
Always shift the automatic transmission into
park position P before turning off the engine.
Otherwise the vehicle could roll away which
could result in an accident and/or serious
personal injury.
Selector lever
Overview of transmission positions
Selector lever in AMG vehicles with P button
PPark position with parking lockRReverse gearNNeutralDDriveAutomatic transmission139Driving and parkingZ

Transmission position and drive
program display:Transmission position display;Drive program display
The current position of the selector lever is
shown by the indicators next to the selector
lever.
The indicators light up when the SmartKey is
inserted into the ignition lock. The indicators
go out when the SmartKey is removed from
the ignition lock.
! If the transmission position display in the
multifunction display is not working, you
should pull away carefully to check whether
the desired transmission position is
engaged. Ideally, you should select
transmission position D and drive program
C . Do not restrict the shift range.
DIRECT SELECT lever
Overview of transmission positions
The DIRECT SELECT lever is on the right of the
steering column.
PPark position with parking lockRReverse gearNNeutralDDrive
i The DIRECT SELECT lever always returns
to its original position. The current
transmission position P, R , N or D appears
in the transmission position display
( Y page 140) in the multifunction display.
Transmission position and drive
program display
The current transmission position and drive
program appear in the multifunction display.
:Transmission position display;Drive program display
i The arrows in the transmission position
display show how and into which
transmission positions you can change
using the DIRECT SELECT lever.
! If the transmission position display in the
multifunction display is not working, you
should pull away carefully to check whether
the desired transmission position is
engaged. Ideally, you should select
transmission position D and drive program
E or S. Do not restrict the shift range.
Engaging park position P
XPush the DIRECT SELECT lever in the
direction of arrow P.
i
The automatic transmission shifts
automatically into park position P if you
open the driver's door when the vehicle is
stationary or driving at very low speed, and
the transmission is in position D or R.
! If the engine speed is too high or the
vehicle is moving, do not shift the
140Automatic transmissionDriving and parking

automatic transmission directly from D to
R , from R to D or directly to P. The
automatic transmission could otherwise be
damaged.
HOLD function or DISTRONIC PLUS: the
automatic transmission automatically
switches to transmission position P if the
vehicle is braked by the HOLD function or
DISTRONIC PLUS. In addition, at least one of
the following conditions must be fulfilled:
R the engine is switched off.
R the driver's door is open and the seat belt
is not in the buckle.
Engaging parking position P in AMG
vehiclesXIf the vehicle is stationary, press P
button :.
Engaging reverse gear R
!
Only shift the automatic transmission to
R when the vehicle is stationary.
XWhen the vehicle is stationary, depress the
brake pedal.XPush the DIRECT SELECT lever up past the
first point of resistance.
Neutral N with ECO start/stop function
activated
The ECO start/stop function switches the
engine off automatically if the vehicle is
braked to a standstill when in neutral N and
the brake is still depressed.
For further information on the ECO start/stop
function ( Y page 135).
Shifting to neutral NXWhen the vehicle is stationary, depress the
brake pedal.XPush the DIRECT SELECT lever up or down
to the first point of resistance.
If the engine has been switched off, the
automatic transmission automatically
switches to N.
Remaining in neutral N
If the automatic transmission is to remain in
neutral N, e.g. for washing the vehicle in car
washes with a towing device, please observe
the following instructions:
GWARNING
When leaving the SmartKey in the starter
switch, do not leave children unattended in
the vehicle. It is possible for children to switch
on the ignition which could result in
unsupervised use of vehicle equipment.
Unsupervised use of vehicle equipment could
result in an accident and/or serious personal
injury.
Using the SmartKey:
R make sure that the ignition is switched on.
R when the vehicle is stationary, depress the
brake pedal and keep it depressed.
R shift to neutral N.
R release the brake pedal.
R if applied, release the parking brake.
R switch off the ignition and leave the
SmartKey in the ignition lock.
Using KEYLESS-GO:
R make sure that the ignition is switched on.
R when the vehicle is stationary, depress the
brake pedal and keep it depressed.
R engage park position P.
R release the brake pedal.
R remove the Start/Stop button from the
ignition lock.
Automatic transmission141Driving and parkingZ