ignition MERCEDES-BENZ C CLASS 2016 Service Manual

Starting the engine
Important safety notes
G WARNING
If children are left unsupervised in the vehicle,
they could: R
open the doors, thus endangering other
people or road users. R
get out and disrupt traffic. R
operate the vehicle's equipment.
Additionally, children could set the vehicle in
motion if, for example, they: R
release the parking brake. R
shifting the automatic transmission out of
park position PR
Start the engine.
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 or animals unattended in the
vehicle. Always keep the SmartKey out of
reach of children.
G WARNING
Combustion engines emit poisonous exhaust
gases such as carbon monoxide. Inhaling
these exhaust gases leads to poisoning. There
is a risk of fatal injury. Therefore never leave
the engine running in enclosed spaces with-
out sufficient ventilation.
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.
! Do not depress the accelerator when start-
ing the engine. General notes The catalytic converter is preheated for up to
30 seconds after a cold start. The sound of the
engine may change during this time.
Automatic transmission X
Shift the transmission to position P
( Y
page 156).
The transmission position display in the mul-
tifunction display shows P ( Y
page 157).
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 146).
If the engine will not start: X
Remove the SmartKey from the ignition lock. X
Reinsert the SmartKey into the ignition lock
after a short waiting period. X
Turn the SmartKey to position 2 in the ignition
lock ( Y
page 146).
The indicator lamps in the instrument cluster
light up ( Y
page 286). X
Turn the SmartKey to position 3 in the ignition
lock ( Y
page 146) and release it as soon as the
engine is running.
Starting procedure with the Start/Stop
button The Start/Stop button is only available on vehi-
cles with KEYLESS-GO or the KEYLESS-GO start
function.
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 the148
Driving
Driving and parking

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 146).
The engine starts.
Starting procedure via smartphone Observe the important safety notes on starting
the engine ( Y
page 148).
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 selectedR
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- vice or maintenance work. There is a risk of
injury.
Always secure the engine against uninten-
tional starting before carrying out mainte-
nance or repair work.
Make sure that the engine cannot be started via
your smartphone before carrying out mainte-
nance or repairs. You can prevent an engine
start via your smartphone, for example, if you: R
switch on the hazard warning lamps R
do not lock the doors R
open the hood.
Pulling away
General notes
G WARNING
If the engine speed is above the idling speed
and you engage transmission position D or R ,
the vehicle could pull away suddenly. There is
a risk of an accident.
When engaging transmission position D or R ,
always firmly depress the brake pedal and do
not simultaneously accelerate.
Depress the accelerator carefully when pulling
away.
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, see the Digital Operator's Manual.
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,
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.
Information on the automatic release of the
electric parking brake ( Y
page 178).Driving 149
Driving and parking Z

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 electric parking brake is applied. R
ESP ®
is malfunctioning.
ECO start/stop function (all vehicles
except PLUG ‑ IN HYBRID)
Introduction This section describes the ECO start/stop func-
tion for all vehicles except PLUG-IN HYBRID
vehicles. Information on the ECO start/stop
function on PLUG-IN HYBRID vehicles
( Y
page 231).
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-
ever you start the engine using the SmartKey or
the Start/Stop button.
If the engine has been switched off automati-
cally by the ECO start/stop function, the

Problems with the engine Problem
Possible causes/consequences and P Solutions
The 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.
Before attempting to start the engine again: X
Turn the SmartKey back to position 0 in the ignition lock.
or X
Press the Start/Stop button repeatedly until all indicator lamps in
the instrument cluster go out. X
Try to start the engine again ( Y
page 148). 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: X
Consult a qualified specialist workshop.
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 352).
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
Try to start the engine again ( Y
page 148).
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 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 333). Observe the warning notes
as you do so and add coolant if necessary. Driving 153
Driving and parking Z

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 or animals unattended in the
vehicle. Always keep the SmartKey out of
reach of children. X
If the transmission is in position D or R : push
the DIRECT SELECT lever up or down to the
first point of resistance. X
If the transmission is in position P : depress
the brake pedal and push the DIRECT SELECT
lever up or down to the first point of resist-
ance.
If you switch the engine off with the transmis-
sion in position R or D , the automatic transmis-
sion shifts to N automatically.
With the SmartKey: if you then open the driv-
er's door or the front-passenger door or remove
the SmartKey from the ignition, the automatic
transmission shifts to P automatically.
With the Start/Stop button: if you then open
the driver's door or the front-passenger door,
the automatic transmission shifts to P automat-
ically.
If you want the automatic transmission to
remain in neutral N , e.g. when having the vehicle
cleaned in an automatic car wash with a towing
system: X
Vehicles with the Start-Stop button:
remove the Start-Stop button from the igni-
tion 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 electric 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 position and drive pro-
gram display The current transmission position and drive pro-
gram appear in the multifunction display.
C
Status symbol drive program D
Transmission position

If you or others come into contact with fuel,
observe the following: R
Wash away fuel from skin immediately
using soap and water. R
If fuel comes into contact with your eyes,
immediately rinse them thoroughly with
clean water. Seek medical assistance with-
out delay. R
If fuel is swallowed, seek medical assis-
tance without delay. Do not induce vomit-
ing. R
Immediately change out of clothing which
has come into contact with fuel.
G WARNING
Electrostatic buildup can create sparks and
ignite fuel vapors. There is a risk of fire and
explosion.
Always touch the vehicle body before opening
the fuel filler flap or touching the fuel pump
nozzle. Any existing electrostatic buildup is
thereby discharged.
Do not get into the vehicle again during the refu-
eling process. Otherwise, electrostatic charge
could build up again.
! Do not use diesel to refuel vehicles with a
gasoline engine. Do not switch on the ignition
if you accidentally refuel with the wrong fuel.
Otherwise, the fuel will enter the fuel system.
Even small amounts of the wrong fuel could
result in damage to the fuel system and the
engine. Notify a qualified specialist workshop
and have the fuel tank and fuel lines drained
completely.
! Overfilling the fuel tank could damage the
fuel system.
! Take care not to spill any fuel on painted
surfaces. You could otherwise damage the
paintwork.
! Use a filter when refueling from a fuel can.
Otherwise, the fuel lines and/or injection sys-
tem could be blocked by particles from the
fuel can.
If you overfill the fuel tank, fuel could spray out
when the fuel pump nozzle is removed. i Flexible Fuel vehicles can be recognized by
the Ethanol up to E85 sticker on the inside of
the fuel filler flap.
For further information on fuel and fuel quality
( Y
page 388).
Refueling
General information Pay attention to the important safety notes
( Y
page 164).
PLUG-IN HYBRID vehicles: pressure in the fuel
tank must be released before refueling.
Except PLUG-IN HYBRID vehicles: if you
unlock/lock the vehicle from the outside, the
fuel filler flap also unlocks/locks.
The position of the fuel filler cap is displayed

Problems with fuel and the fuel tank Problem
Possible causes/consequences and P Solutions
Fuel is leaking from the
vehicle.
G WARNING
The fuel line or the fuel tank is faulty.
Risk of explosion or fire. X
Apply the electric parking brake. X
Switch off the engine. X
Remove the SmartKey from the ignition lock.
or, in vehicles with KEYLESS-GO start-function or KEYLESS ‑ GOX
Open the driver's door.
The on-board electronics now have status 0 . This is the same as the
SmartKey having been removed. X
Do not restart the engine under any circumstances. X
Consult a qualified specialist workshop.
The fuel filler flap cannot
be opened. The fuel filler flap is not unlocked. X
Unlock the vehicle ( Y
page 81).X
PLUG-IN HYBRID Vehicles: depressurize the fuel tank
( Y
page 165).
The SmartKey battery is discharged or nearly discharged. X
Unlock the vehicle using the mechanical key ( Y
page 83).
The fuel filler flap is unlocked, but the opening mechanism is jammed. X
Consult a qualified specialist workshop.
Charging the high-voltage battery
(PLUG-IN HYBRID vehicles)
Important safety notes
G DANGER
The vehicle's high-voltage electrical system is
under high voltage. If you modify components
in the vehicle's high-voltage electrical system
or touch damaged components, you may be
electrocuted. The components in the vehi-
cle's high-voltage electrical system may be
damaged in an accident, although the damage
is not visible. There is a risk of fatal injury.
Following an accident, do not touch any high-
voltage components and never modify the
vehicle's high-voltage electrical system. Have
the vehicle towed away after an accident and the vehicle's high-voltage electrical system
checked by a qualified specialist workshop.
G WARNING
In the event of a vehicle fire, the internal pres-
sure of the high-voltage battery can exceed a
critical value. In this case flammable gas
escapes through a ventilation valve on the
underbody. The gas can ignite. There is a risk
of injury.
Leave the danger zone immediately. Secure
the danger area at a suitable distance, whilst
observing legal requirements.
G DANGER
If you use incorrectly installed mains sockets
or adapters, extension cables or similar to
connect the charging cable to a mains socket,168
Charging the high-voltage battery (PLUG-IN HYBRID vehicles)
Driving and parking

Indicator
lamp
Lights up
orange A charging break for the high-
voltage battery is taking
place.
The indicator lamp goes out
after approximately
90 seconds.
Lights up
green The high-voltage battery is
fully charged.
The indicator lamp goes out
after approximately
90 seconds.
i If the indicator lamp is off, lock or unlock the
vehicle. The indicator lamp then displays the
current status of the charging process again.
Connecting the charging cable
X
Shift the transmission to position P .X
Switch the ignition off. X
Press the charge socket flap in the direction
of arrow C .
The charge socket flap swings up. X
Press fastener D to the left.
Socket cap

Connecting the charging cable
X
Shift the transmission to position P .X
Switch the ignition off. X
Press the charge socket flap in direction of
arrow C .
The charge socket flap swings up. X
Press fastener D to the left.
Socket cap

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 electric 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. R
the empty vehicle must be secured at the
front axle with a wheel chock or similar, for
example, on uphill or downhill gradients. R
a laden vehicle must also be secured at the
rear axle with a wheel chock or similar, for
example, on 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 electric parking brake. X
Shift the transmission to position P .X
With the SmartKey: turn the SmartKey to
position 0 in the ignition lock and remove it.
The immobilizer is activated. X
With the Start/Stop button: press the
Start/Stop button ( Y
page 146).
The engine stops and all the indicator lamps in
the instrument cluster go out.
When the driver's door is closed, this corre-
sponds to SmartKey position 1 . When the
driver's door is open, this corresponds to
SmartKey position 0 : "SmartKey removed".
If you switch the engine off with the transmis-
sion in position R or D , the automatic transmis-
sion shifts to N automatically.
With the SmartKey: if you then open the driv-
er's door or the front-passenger door or remove
the SmartKey from the ignition, the automatic
transmission shifts to P automatically.
With the Start/Stop button: if you then open
the driver's door or the front-passenger door,
the automatic transmission shifts to P automat-
ically.
If you want the automatic transmission to
remain in neutral N , e.g. when having the vehicle
cleaned in an automatic car wash with a towing
system: X
Vehicles with the Start-Stop button:
remove the Start-Stop button from the igni-
tion lock. X
Insert the SmartKey into the ignition lock. X
All vehicles: switch the ignition on.Parking 177
Driving and parking Z