warning light MERCEDES-BENZ B-CLASS HATCHBACK 2014 Workshop Manual

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 322). 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. Manual transmission
Gear lever
! Only engage gear when the clutch pedal is
depressed.
! When shifting to
5thand 6thgear, you
must press the shift lever to the right. Oth- erwise, you could shift unintentionally into
3rd or4th gear and damage the engine or
transmission.
If you shift down at too high a speed (trans-
mission braking), this can cause the engine
to overrev, leading to engine damage.
Do not use the clutch bite point to keep the vehicle stationary on uphill gradients.
There is otherwise a risk of damaging the
clutch.
! On long and steep downhill gradients,
especially if the vehicle is laden or towing a trailer, you must shift into gear
1, 2or3in
good time. This uses the engine's braking
effect. This relieves the load on the brake
system and prevents the brakes from over-
heating and wearing too quickly. k
Reverse gear
1 -6
Forward gears 168
Manual transmissionDriving and parking

Brakes
Important safety notes G
WARNING
If you shift down on a slippery road surface in an attempt to increase the engine's braking
effect, the drive wheels could lose their grip.
This increases the risk of skidding and having
an accident.
Do not shift down for additional engine brak-
ing on a slippery road surface.
Downhill gradients Change into a lower gear in good time on long
and steep downhill gradients. Take particular note of this when driving a laden vehicle and
when towing a trailer. For vehicles with auto-
matic transmission, you need to have selec-
ted manual drive program M(Y page 175).
This also applies if you have activated cruise
control, SPEEDTRONIC or DISTRONIC PLUS.
This will use the braking effect of the engine,
so less braking will be required to maintain
vehicle speed. This relieves the load on the
brake system and prevents the brakes from
overheating and wearing too quickly.
Briefly depressing the accelerator pedal on
downhill gradients while the manual drive
program Mis temporarily activated (vehicles
with automatic transmission): the automatic
transmission may switch back to the last
active automatic drive program Eor S. The
automatic transmission may shift to a higher
gear. This can reduce the engine's braking
effect.
Heavy and light loads G
WARNING
The braking system can overheat if you leave your foot on the brake pedal while driving.
This increases the braking distance and could
even cause the braking system to fail. There is
a risk of an accident. Never use the brake pedal as a footrest. Do
not simultaneously depress both the brake
pedal and the accelerator pedal while driving.
! Depressing the brake pedal constantly
results in excessive and premature wear to
the brake pads.
If heavy demands are made on the brakes, do not park the vehicle immediately. Drive on for
a short while. This allows the airflow to cool
the brakes more quickly.
If the brakes have been used only moderately, you should occasionally test their effective-
ness. To do this, brake more firmly from a
higher speed, paying attention to traffic con-
ditions. This improves the grip of the brakes.
Wet road surfaces If you have driven for a long time in heavy rain
without braking, there may be a delayed reac- tion from the brakes when braking for the first
time. This may also occur after a car wash or after driving through deep water.
You will have to depress the brake pedal more
firmly. Maintain a greater distance to the vehi-
cle in front.
After driving on a wet road or having the vehi- cle washed, brake firmly while paying atten-
tion to the traffic conditions. This will warm up
the brake discs, thereby drying them more
quickly and protecting them against corro-
sion.
Limited braking performance on salt-
treated roads If you drive on salt-treated roads, a layer of
salt may form on the brake discs and pads.
This can increase the braking distance con-
siderably.186
Driving tipsDriving an
d parking

You should drive particularly carefully on slip-
pery road surfaces. Avoid sudden accelera-
tion, steering and braking manoeuvres. Do
not use cruise control or DISTRONIC PLUS.
If the vehicle threatens to skid or cannot be
stopped when moving at low speed:
X Vehicles with manual transmission:
shift to neutral.
X Vehicles with automatic transmission:
shift the transmission to position N.
X Try to bring the vehicle under control by
using corrective steering.
The outside temperature indicator is not
designed to serve as an ice-warning device
and is therefore unsuitable for that purpose.
Changes in the outside temperature are dis-
played after a short delay.
Indicated temperatures just above the freez-
ing point do not guarantee that the road sur-
face is free of ice. The road may still be icy,
especially in wooded areas or on bridges.
You should pay special attention to road con-
ditions when temperatures are around freez-
ing point.
Further information on driving with snow
chains (Y page 355).
Further information on driving with summer
tyres (Y page 354).
Observe the notes in the "Winter operation"
section (Y page 354). Driving systems
Cruise control
General notes Cruise control maintains a constant road
speed for you. It brakes automatically in order to avoid exceeding the set speed. You must
select a lower gear in good time on long and
steep downhill gradients, especially if the
vehicle is laden or towing a trailer. For vehi-
cles with automatic transmission, you need to have selected manual drive program M
(Y page 175). By doing so, you will make use 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 canstore any road speed above 30 km/h.
The speed indicated in the speedometer maydiffer 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. 188
Driving systemsDriving and parking

Storing the current speed or calling up the
last stored speed G
WARNING
If you call up a stored speed and this is dif-
ferent from the current speed, the vehicle
accelerates or brakes. If you do not know
what the stored speed is, the vehicle may
accelerate or brake unexpectedly. There is a
risk of an accident.
Take the traffic conditions into account
before calling up the stored speed. If you do
not know what the stored speed is, store the
desired speed again.
X Briefly pull the cruise control lever towards
you =.
X Remove your foot from the accelerator
pedal.
The first time cruise control is activated, it
stores the current speed or regulates the
speed of the vehicle to the previously
stored speed.
Setting a speed Bear in mind that it may take a brief moment
until the vehicle has accelerated or braked to the set speed.
X Press the cruise control lever up :for a
higher speed or down ?for a lower speed.
X Keep the cruise control lever pressed until
the desired speed is reached.
X Release the cruise control lever.
The new speed is stored.
X To adjust the set speed in 1 km/h incre-
ments: briefly press the cruise control
lever up :or down ?to the pressure
point.
The last stored speed increases or decrea-
ses in 1 km/h increments.
X To adjust the set speed in 10 km/h
increments: briefly press the cruise con-
trol lever up :or down ?beyond the
pressure point.
The last stored speed increases or decrea- ses in 10 km/h increments. i
Cruise control is not deactivated if you
depress the accelerator pedal. For exam-
ple, if you accelerate briefly to overtake,
cruise control adjusts the vehicle's speed
to the last speed stored after you have fin- ished overtaking.
Deactivating cruise control There are several ways to deactivate cruise
control:
X Briefly press the cruise control lever for-
wards B.
or
X Brake.
or X Briefly press the cruise control lever in the
direction of arrow A.
Variable SPEEDTRONIC is selected. LIM
indicator lamp ;in the cruise control lever
lights up.
Cruise control is automatically deactivated if: R the vehicle is secured with the electric
parking brake
R you are driving at less than 30 km/h
R ESP ®
intervenes or you deactivate ESP ®
R while driving a vehicle with manual trans-
mission, you shift into neutral or depress
the clutch pedal for longer than six seconds
R on vehicles with manual transmission, you
shift to a gear that is too high, and as a
result the engine speed is too low
R on vehicles with automatic transmission,
you shift to position Nwhile driving
If cruise control is deactivated, you will hear a
warning tone. You will see the Cruise con‐
Cruise con‐
trol off trol off message in the multifunction dis-
play for approximately five seconds.
i The last speed stored is cleared when you
switch off the engine. 190
Driving systemsDriving and parking

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 lever up
:to the pressure point for a
higher speed or down ;for a lower speed.
or
X Keep the cruise control lever pressed to 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.
Switching SPEEDTRONIC to passive
If you depress the accelerator pedal beyond
the pressure point (kickdown), SPEED-
TRONIC is switched to passive mode. The fol-
lowing message appears in the multifunction
display: SPEEDTRONIC passive
SPEEDTRONIC passive.
You can then exceed the stored speed.
SPEEDTRONIC is activated again if you: R drive slower than the stored speed without
kickdown
R set a new speed or
R call up the last speed stored again
The SPEEDTRONIC passive SPEEDTRONIC passive message in the
multifunction display disappears.
Deactivating variable SPEEDTRONIC
It is not possible to deactivate variable
SPEEDTRONIC by braking.
There are several ways to deactivate variable SPEEDTRONIC:
X Briefly press the cruise control lever for-
wards B.
or
X Briefly press the cruise control lever in the
direction of arrow A.
LIM indicator lamp ;in the cruise control
lever goes out. Variable SPEEDTRONIC is
deactivated.
Cruise control or DISTRONIC PLUS is selec- ted.
Vehicles with manual transmission:
SPEEDTRONIC switches off if you shift to a
higher gear and as a result, the engine speed
is too low.
i The last speed stored is cleared when you
switch off the engine. 192
Driving systemsDriving and parking

Permanent SPEEDTRONIC
You can use the on-board computer to limit
the speed permanently to a value between
160 km/h(e.g. for driving on winter tyres) and the maximum speed (Y page 247).
Shortly before the stored speed is reached, it
appears in the multifunction display.
Permanent SPEEDTRONIC remains active
even if variable SPEEDTRONIC is deactivated.
You cannot exceed the stored limit speed
even if you depress the accelerator pedal
beyond the pressure point (kickdown). DISTRONIC PLUS
General notes DISTRONIC PLUS regulates the speed and
automatically helps you maintain the dis-
tance to the vehicle detected in front. Vehi-
cles are detected with the aid of the radar
sensor system. DISTRONIC PLUS brakes
automatically to avoid exceeding the set
speed or to maintain the designated distance from the vehicle in front.
Change into a lower gear in good time on long
and steep downhill gradients. Take particular
note of this when driving a laden vehicle. By
doing so, you will make use 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.
If DISTRONIC PLUS detects that there is a risk of a collision, you will be warned visually and
acoustically. Without your intervention,
DISTRONIC PLUS cannot prevent a collision.
An intermittent warning tone will then sound
and the distance warning lamp will light up in the instrument cluster. Brake immediately to
increase the distance to the vehicle driving in
front, or take evasive action, provided it is
safe to do so.
DISTRONIC PLUS operates in the range
between 0 km/h and 200 km/h.
Do not use DISTRONIC PLUS while driving on roads with steep gradients. Important safety notes G
WARNING
DISTRONIC PLUS does not react to:
R people or animals
R stationary obstacles on the road, e.g. stop-
ped or parked vehicles
R oncoming and crossing traffic
As a result, DISTRONIC PLUS may neither give
warnings nor intervene in such situations.
There is a risk of an accident.
Always pay careful attention to the traffic sit- uation and be ready to brake. G
WARNING
DISTRONIC PLUS cannot always clearly rec-
ognise other road users and complex traffic
conditions.
In such cases, DISTRONIC PLUS may:
R give an unnecessary warning and then
brake the vehicle
R neither give a warning nor intervene
R accelerate or brake unexpectedly
There is a risk of an accident.
Continue to drive carefully and be prepared to
brake, particularly if DISTRONIC PLUS warns
you. G
WARNING
DISTRONIC PLUS brakes your vehicle with up to 50% of the maximum possible deceleration.
If this deceleration is not sufficient,
DISTRONIC PLUS alerts you with a visual and
acoustic warning. There is a risk of an acci-
dent.
Apply the brakes yourself in these situations
and try to take evasive action.
! When DISTRONIC PLUS or the HOLD
function is activated, the vehicle brakes
automatically in certain situations. Driving systems
193Driving and parking Z

Deactivating DISTRONIC PLUS
There are several ways to deactivate
DISTRONIC PLUS:
X Briefly press the cruise control lever for-
wards :.
or X Brake, unless the vehicle is stationary.
or X Briefly press the cruise control lever in the
direction of arrow =.
Variable SPEEDTRONIC is selected. LIM
indicator lamp ;in the cruise control lever
lights up.
If you deactivate DISTRONIC PLUS, you will
see the DISTRONIC
DISTRONIC PLUS PLUSoff
offmessage in the
multifunction display for approximately five
seconds.
i The last speed stored remains stored until
you switch off the engine. DISTRONIC PLUS
is not deactivated if you depress the accel-
erator pedal.
DISTRONIC PLUS is automatically deactiva-
ted if:
R you apply the electric parking brake or if the
vehicle is automatically secured with the
electric parking brake
R ESP ®
intervenes or you deactivate ESP ®
R the transmission is in the P,Ror Nposition
R you pull the cruise control lever towards
you in order to pull away and the front-
passenger door or one of the rear doors is
open R
the vehicle is skidding
R you activate Active Parking Assist
If DISTRONIC PLUS is deactivated, you will
hear a warning tone. You will see the
DISTRONIC PLUS off
DISTRONIC PLUS off message in the multi-
function display for approximately five sec-
onds.
DISTRONIC PLUS displays in the instru-
ment cluster Displays in the speedometer
Example: DISTRONIC PLUS displays in the speed-
ometer
When DISTRONIC PLUS is activated and there
are no vehicles detected in front, one or two
segments ;in the set speed range light up.
If DISTRONIC PLUS detects a vehicle in front, segments ;between speed of the vehicle in
front =and stored speed :light up.
i For design reasons, the speed displayed
in the speedometer may differ slightly from the speed set for DISTRONIC PLUS.
Display when DISTRONIC PLUS is deacti-
vated
Vehicles with a black and white multi-
function display: you can select the distance
display function using the on-board com-
puter.
Vehicles with a colour multifunction dis-
play: in the Assistance menu of the on-board
computer, you can select the assistance
graphic. 198
Driving syste
msDriving and parking

detected vehicle turns a corner and reveals
an obstacle or stationary vehicle, DISTRONIC PLUS will not brake for these.
Crossing vehicles DISTRONIC PLUS may detect vehicles that
are crossing your lane by mistake. Activating DISTRONIC PLUS at traffic lights with cross-
ing traffic, for example, could cause your vehi-
cle to pull away unintentionally. 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 manoeuvring 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 cancelled and the HOLD function is deactivated when you depress theaccelerator 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 is deactivated by the
accelerator pedal being depressed, e.g. by
a vehicle occupant
R the electrical system in the engine com-
partment, the battery or the fuses are tam-
pered with
R the battery is disconnected
There is a risk of an accident.
Before leaving the vehicle, always deactivate
the HOLD function and secure the vehicle
from rolling away.
! When DISTRONIC PLUS or the HOLD
function is activated, the vehicle brakes
automatically 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 away
R in a car wash
Deactivating the HOLD function
(Y page 202).
Activation conditions You can activate the HOLD function if:
R the vehicle is stationary
R the engine is running or if it has been auto-
matically switched off by the ECO start/
stop function
R the driver's door is closed or if your seat
belt is fastened
R the electric parking brake is released
R DISTRONIC PLUS is deactivated
R the transmission is in position D,Ror Non
vehicles with automatic transmission Driving systems
201Driving and parking Z

:
Example: sensors in the front bumper,
left-hand side
The sensors must be free of dirt, ice and
slush. Otherwise, they may not function cor-
rectly. Clean the sensors regularly, taking
care not to scratch or damage them
(Y page 328).
Range Front sensors
Centre Approx. 100 cm
Corners Approx. 60 cm Rear sensors
Centre Approx. 120 cm
Corners Approx. 80 cm
Minimum distance
Centre Approx. 20 cm
Corners Approx. 20 cm
If there is an obstacle within this range, the
relevant warning displays light up and a warn- ing tone sounds. If the distance falls below
the minimum, the distance may no longer be
shown.
Warning displays Warning display for the front area
:
Segments on the left-hand side of the
vehicle
; Segments on the right-hand side of the
vehicle
= Segments showing operational readiness
The warning displays show the distance
between the sensors and the obstacle. The
warning display for the front area is located
on the dashboard above the centre air vents.
The warning display for the rear area is loca-
ted on the roof lining in the rear compart-
ment.
The warning display for each side of the vehi- cle is divided into five yellow and two red seg-ments. PARKTRONIC is operational if yellow 204
Driving systemsDriving an
d parking

segments showing operational readiness
=
light up.
The gear lever position or the transmission
position of the automatic transmission and
the direction in which the vehicle is rolling
determine which warning display is active
when the engine is running.
Manual transmission: Gear lever posi-
tion Warning display
Forward gear
or
Neutral
Front area activated
Reverse gear
or
the vehicle is rolling backwards Rear and front areas
activated
Automatic transmission:
Transmission
position Warning display
D
Front area activated
R,
Nor the vehicle
is rolling back-
wards Rear and front areas
activated
P
No areas activated
One or more segments light up as the vehicle
approaches an obstacle, depending on the
vehicle's distance from the obstacle.
From the:
R sixth segment onwards, you will hear an
intermittent warning tone for approx-
imately two seconds.
R seventh segment onwards, you will hear a
warning tone for approximately two sec-
onds. This indicates that you have now
reached the minimum distance. Deactivating/activating PARKTRONIC
:
Indicator lamp
; To deactivate/activate PARKTRONIC
If indicator lamp :lights up, PARKTRONIC is
deactivated.
i PARKTRONIC is automatically activated
when you turn the key to position 2in the
ignition lock. Driving systems
205Driving and parking Z