2015 MERCEDES-BENZ A-CLASS HATCHBACK check engine light

Problem
Possible causes/consequences and
M
MSolutions There is a fault with KEYLESS-GO.
X Lock/unlock the vehicle using the remote control function of
the key.
X Have the vehicle and key checked at a qualified specialist work-
shop.
If the vehicle can also not be locked/unlocked using the remote
control function:
X Lock (Y page 91) or unlock (Y page 92) the vehicle using the
emergency key element.
X Have the vehicle and key checked at a qualified specialist work-
shop. The engine cannot be
started using the 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 347).
or
X Jump-start the vehicle (Y page 348).
or
X Consult a qualified specialist workshop. The engine cannot be
started using the Start/
Stop button. The key is
in the vehicle. The vehicle is locked.
X Unlock the vehicle and try to start the vehicle again. The key battery is discharged or nearly discharged.
X Check the key battery (Y page 86) and replace it if necessary
(Y page 86).
If this does not work: X Start your vehicle with the key in the ignition lock. There is interference from a powerful source of radio waves.
X Start your vehicle with the key in the ignition lock. 88
KeyOpening and closing

Useful information
i This Owner's Manual describes all mod-
els, series and optional equipment for your
vehicle that were available at the time of
going to press. National variations are pos- sible. Note that your vehicle may not be
equipped with all of the functions descri-
bed. This is also the case for systems and
functions relevant to safety.
i Read the information on qualified special-
ist workshops: (Y page 24). Correct driver's seat position
G
WARNING
You could lose control of the vehicle while
driving if you:
R adjust the driver's seat, steering wheel or
mirrors
R fasten the seat belt
There is a risk of an accident.
Adjust the driver's seat, head restraint, steer-
ing wheel and mirrors and fasten your seat
belt before starting the engine. X
Observe the safety notes on seat adjust-
ment (Y page 107).
X Make sure that seat =is correctly adjus-
ted.
Manual seat adjustment (Y page 108)
Electrical seat adjustment (Y page 109)
When adjusting the seat, make sure that:
R you are as far away from the driver's air-
bag as possible
R you are sitting in a normal upright posi-
tion
R you can fasten the seat belt properly
R you have moved the backrest to an
almost vertical position
R you have set the seat angle so that your
thighs are gently supported
R you can depress the pedals properly
X Check whether the head restraint is adjus-
ted correctly (Y page 109).
When doing so, make sure that you have
adjusted the head restraint so that the back of your head is supported at eye level by the
centre of the head restraint.
X Observe the safety notes on steering col-
umn adjustment (Y page 112).
X Make sure that steering wheel :is adjus-
ted correctly.
Adjusts the steering wheel (Y page 112)
When adjusting the steering wheel, make
sure that:
R you can hold the steering wheel with your
arms slightly bent
R you can move your legs freely
R you can see all the displays in the instru-
ment cluster clearly
X Observe the safety guidelines for seat belts
(Y page 42).
X Check whether you have fastened seat
belt ;properly (Y page 44).106
Correct driver's seat positionSeats, steering wheel and mirrors

Problems with the seat heating
Problem
Possible causes/consequences and
M
MSolutions The seat heating has
switched off prema-
turely or cannot be
switched on. The on-board voltage is too low because too many electrical con-
sumers are switched on.
X Switch off electrical consumers that you do not need, such as
the rear window heating or interior lighting.
Once the battery is sufficiently charged, the seat heating will
switch back on automatically. Steering wheel
Important safety notes
G
WARNING
You could lose control of the vehicle while
driving if you:
R adjust the driver's seat, steering wheel or
mirrors
R fasten the seat belt
There is a risk of an accident.
Adjust the driver's seat, head restraint, steer-
ing wheel and mirrors and fasten your seat
belt before starting the engine. G
WARNING
Children could become trapped by the steer-
ing wheel if they adjust it. There is a risk of
injury.
When leaving the vehicle, always take the key with you and lock the vehicle. Never leave
children unattended in the vehicle. Adjusting the steering wheel
G
WARNING
The steering wheel may move unexpectedly if you adjust it while driving. This could cause
you to lose control of the vehicle. There is a
risk of an accident.
Make sure that the steering wheel is locked
before driving off. Never unlock the steering
wheel when the vehicle is in motion. :
Release lever
; Adjusts the steering wheel height
= Adjusts the steering wheel position (fore-
and-aft adjustment)
X Push release lever :down completely.
The steering column is unlocked.
X Adjust the steering wheel to the desired
position.
X Push release lever :up as far as it will go.
The steering column is locked.
X Check if the steering column is locked.
When doing so, try to push the steering
wheel up or down or try to move it in the
fore-and-aft direction. 112
Steering wheelSeats, steering wheel and mirrors

Problem
Possible causes/consequences and
M
MSolutions Vehicles with a petrol
engine:
The engine is not run-
ning smoothly and is
misfiring. 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 con-
verter and damage it.
X Have the cause rectified immediately at a qualified specialist
workshop. The coolant tempera-
ture display is showing
more than 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 326). Observe the warning
notes as you do so and top up the coolant if necessary. If the coolant level is correct, the engine radiator fan may be faulty.
The coolant is too hot and the engine is no longer being cooled
sufficiently.
X If the coolant temperature is below 120 †, you can continue
driving to the nearest qualified specialist workshop.
X Avoid heavy loads on the engine as you do so, e.g. driving in
mountainous terrain and stop-start traffic. 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 char- acteristics will change:
R the drive (engine and transmission man-
agement)
R the suspension (vehicles with damping sys-
tem or AMG RIDE CONTROL)
R the steering
R the availability of the ECO start/stop func-
tion
R the climate control
If the ignition is switched off for less than four hours, the previously selected drive program
is activated when the engine is next started. If the ignition is switched off for more than four hours, drive program
Cis activated when the
engine is next started. X
Press DYNAMIC SELECT controller :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. 166
DYNAMIC SELECT button (all vehicles except Mercedes-AMG vehicles)Driving and parking

The function of the electric parking brake is
dependent on the on-board voltage. If the on-
board voltage is low or if there is a malfunc-
tion in the system, it may not be possible to
apply the released parking brake.
X If this is the case, only park the vehicle on
level ground and secure it to prevent it from
rolling away.
X Vehicles with automatic transmission:
shift the automatic transmission to posi-
tion P.
X Vehicles with manual transmission:
engage first gear.
It may not be possible to release an applied
parking brake if the on-board voltage is low or
if there is a malfunction in the system. Con-
tact a qualified specialist workshop.
The electric parking brake carries out a func-
tion check at regular intervals when the
engine is switched off. Noises that occur are
normal.
Applying or releasing manually X
To apply: push handle :.
When the electric parking brake is applied, the ! red indicator lamp lights up in the
instrument cluster.
The electric parking brake can also be
applied when the key is removed.
X To release: pull handle:.
The red !indicator lamp in the instru-
ment cluster goes out. The electric parking brake can only be
released:
R when the key is in position 1or 2in the
ignition lock (Y page 157) or
R if the ignition was switched on using the
Start/Stop button
Applying automatically (vehicles with
automatic transmission) The electric parking brake is automatically
applied when the transmission is in position P
and:
R the engine is switched off or
R the driver is not wearing a seat belt and the
driver's door is opened
To prevent the electric parking brake from
being automatically applied, pull handle :.
The electric parking brake is also engaged
automatically if:
R DISTRONIC PLUS brings the vehicle to a
standstill or
R the HOLD function is keeping the vehicle
stationary
R Active Parking Assist is keeping the vehicle
stationary
In addition, at least one of the following con-
ditions must be fulfilled:
R there is a system malfunction
R the power supply is insufficient
R the vehicle is stationary for a lengthy period
The red !indicator lamp in the instrument
cluster lights up.
The electric parking brake is not automati-
cally applied if the engine is switched off by
the ECO start/stop function.
Applying automatically (vehicles with
manual transmission) When the vehicle's HOLD function is holding
the vehicle at a standstill, the electric parking
brake is applied automatically. 186
ParkingDriving and parking

of the braking effect of the engine. This
relieves the load on the brake system and
prevents the brakes from overheating and
wearing too quickly.
Use cruise control only if road and traffic con- ditions are appropriate for maintaining a
steady speed for a prolonged period. You can
store any road speed above 30 km/h.
The speed indicated in the speedometer may differ slightly from the speed stored.
Important safety notes If you fail to adapt your driving style, cruise
control can neither reduce the risk of an acci-
dent nor override the laws of physics. Cruise
control cannot take into account road,
weather or traffic conditions. Cruise control is only an aid. You are responsible for the dis-
tance to the vehicle in front, for vehicle speed,
for braking in good time, and for staying in
lane.
Do not use cruise control:
R in road and traffic conditions which do not
allow you to maintain a constant speed, e.g.
in heavy traffic or on winding roads
R on smooth or slippery roads. Braking or
accelerating can cause the drive wheels to lose traction and the vehicle could then
skid
R when there is poor visibility, e.g. due to fog,
heavy rain or snow
If there is a change of drivers, advise the new
driver of the speed stored. Cruise control lever :
To activate or increase speed
; LIM indicator lamp
= To activate at the current speed/last
stored speed
? To activate or reduce speed
A To switch between cruise control and var-
iable SPEEDTRONIC
B To deactivate cruise control
You can operate cruise control and variable
SPEEDTRONIC with the cruise control lever.
The LIM indicator lamp on the cruise control
lever indicates which system you have selec- ted:
R LIM indicator lamp off: cruise control is
selected
R LIM indicator lamp on: variable SPEED-
TRONIC is selected
When you activate cruise control, the stored
speed is shown in the multifunction display
for five seconds.
Selecting cruise control X
To select cruise control: check whether
LIM indicator lamp ;is on or off.
If it is off, cruise control is already selected.
X If it is not, press the cruise control lever in
the direction of arrow A.
LIM indicator lamp ;in the cruise control
lever goes out. Cruise control is selected. 192
Driving systemsDriving and parking

Variable SPEEDTRONIC
General notes
:
To activate or increase speed
; LIM indicator lamp
= To activate at the current speed/last
stored speed
? To activate or reduce speed
A To switch between cruise control and var-
iable SPEEDTRONIC
B To deactivate cruise control
With the cruise control lever, you can operate
cruise control or DISTRONIC PLUS and vari-
able SPEEDTRONIC.
The LIM indicator lamp on the cruise control
lever indicates which system you have selec- ted:
R LIM indicator lamp off: cruise control or
DISTRONIC PLUS is selected
R LIM indicator lamp on: variable SPEED-
TRONIC is selected
When the engine is running, you can use the
cruise control lever to limit the speed to any
speed between 30 km/h and the technically
permitted maximum speed of the vehicle. If
the set value of permanent SPEEDTRONIC is
lower then this value applies (Y page 196).
Selecting variable SPEEDTRONIC X Check whether LIM indicator lamp ;is on.
If it is on, variable SPEEDTRONIC is already selected. If it is not, press the cruise control lever in
the direction of arrow
A.
LIM indicator lamp ;in the cruise control
lever lights up. Variable SPEEDTRONIC is
selected.
Storing the current speed
You can use the cruise control lever to limit
the speed to any speed above 30 km/h while
the engine is running.
X Briefly press the cruise control lever up :
or down ?.
The current speed is stored and shown in
the multifunction display.
Storing or calling up the speed G
WARNING
If you call up the stored speed and it is lower
than the current speed, the vehicle deceler-
ates. If you do not know the stored speed, the vehicle could decelerate unexpectedly. There
is a risk of an accident.
Pay attention to the road and traffic condi-
tions before calling up the stored speed. If you do not know the stored speed, store the
desired speed again.
X Briefly pull the cruise control lever towards
you =.
Setting a speed X To adjust the set speed in 10 km/h
increments: briefly press the cruise con-
trol lever up :beyond the pressure point
for a higher speed, or down ?for a lower
speed.
or X Keep the cruise control lever pressed
beyond the pressure point until the desired
speed is set. Press the cruise control lever
up : for a higher speed or down ?for a
lower speed.
X To adjust the set speed in 1 km/h incre-
ments: briefly press the cruise control Driving systems
195Driving and parking Z

Activating Blind Spot Assist
X Make sure that Blind Spot Assist is activa-
ted in the on-board computer
(Y page 249).
X Turn the key to position 2in the ignition
lock.
Warning lamps :in the exterior mirrors
light up red for approximately 1.5 seconds
and then turn yellow.
Towing a trailer
If you couple up a trailer, make sure that you have correctly established the electrical con-
nection. This can be accomplished by check- ing the trailer lighting. Blind Spot Assist is
then deactivated. The indicator lamps in the
exterior mirrors light up yellow and the
Blind
Blind Spot SpotAssist
Assist not
notavailable
available when
when
towing a trailer See Owner's Manual
towing a trailer See Owner's Manual
message appears in the multifunction dis-
play.
i You can deactivate the indicator lamps in
the exterior mirrors.
To do so, you will need to deactivate Blind
Spot Assist if:
R the key is in position 2in the ignition lock
R the engine is not running
R the electrical connection to the trailer
has been established
Lane Keeping Assist General notes
Lane Keeping Assist monitors the area in
front of your vehicle by means of multifunc- tion camera
:attached at the top of the
windscreen. Lane Keeping Assist detects lane markings on the road and can warn you
before you leave your lane unintentionally.
This function is available in a speed range
between 60 km/h and 200 km/h.
A warning may be given if a front wheel
passes over a lane marking. It will warn you by
means of intermittent vibration through the
steering wheel for up to 1.5 seconds.
Important safety notes G
WARNING
Lane Keeping Assist cannot always clearly
identify lane markings.
In these cases, Lane Keeping Assist may:
R give an unnecessary warning
R not give a warning
There is a risk of an accident.
Always pay particular attention to the traffic
situation and keep in lane, especially if Lane
Keeping Assist alerts you. G
WARNING
The Lane Keeping Assist warning does not
return the vehicle to the original lane. There is a risk of an accident.
Always steer, apply the brakes or accelerate
the vehicle yourself, especially if Lane Keep-
ing Assist alerts you.
If you fail to adapt your driving style, Lane
Keeping Assist can neither reduce the risk of
an accident nor override the laws of physics. Lane Keeping Assist cannot take into account
road, weather or traffic conditions. Lane
Keeping Assist is only an aid. You are respon- sible for the distance to the vehicle in front,
for vehicle speed, for braking in good time and
for staying in lane.
Lane Keeping Assist does not keep your vehi- cle in its lane. 228
Driving systemsDriving and pa
rking