2012 MERCEDES-BENZ A CLASS instrument cluster

Function Page
:
Overhead control panel 36
;
PARKTRONIC warning dis-
play
182
=
Combination switch 107
?
Instrument cluster 30
A
Horn
B
DIRECT SELECT lever 151
C
Steering wheel gearshift
paddles
156
D
Light switch
105 Function Page
E
Electric parking brake 163
F
Opening the bonnet 285
G
Diagnostics connection 23
H
Ignition lock 143
I
Adjusting the steering
wheel
98
J
Cruise control lever 169
K
Climate control systems 122Cockpit
29At a glance

Instrument cluster
Displays and controls
i
Instrument cluster: kilometres Function Page
:
Speedometer with seg-
ments
209
;
Multifunction display 210
=
Rev counter
208 Function Page
?
Coolant temperature 208
A
Fuel gauge
B
Instrument cluster lighting 20830
Instrument clusterAt a glance

i
Instrument cluster: miles Function Page
:
Speedometer with seg-
ments
209
;
Multifunction display 210
=
Rev counter
208 Function Page
?
Coolant temperature 208
A
Fuel gauge
B
Instrument cluster lighting 208Instrument cluster
31At a glance

Warning and indicator lamps
Function Page
:
L Dipped-beam head-
lamps
105
;
T Side lamps
106
=
K Main-beam head-
lamps
107
?
÷ ESP
® 260
A
! Electric parking brake
(red)
263
B
!
Electric parking brake
(yellow)
263
C
· Distance warning
266
D
#! Turn signals
107
E
6 SRS
263
F
ü Seat belts
257
G
% Diesel engine: pre-
glow
144
M SPORT handling
mode in AMG vehicles
261 Function Page
H
? Coolant
264
I
R Rear foglamp
106
J
N Front foglamps
106
K
; Engine diagnostics
264
L
h
This lamp has no func-
tion
M
æ Reserve fuel
264
N
å ESP
®
OFF 260
O
! ABS
258
P
J Brakes
25832
Instrument cluster
At a glance

SRS (Supplemental Restraint System)
Introduction Supplemental Restraint System (SRS) with:
R
The 6 SRS warning lamp
R Airbags
R Airbag control unit (with crash sensors)
R Belt
tensioners for the front seat belts and
the outer seat belts in the rear
R Seat belt force limiters for the front seat
belts and the outer seat belts in the rear
SRS reduces the risk of occupants coming
into contact with parts of the vehicle's interior
in the event of an accident. It can also reduce
the forces to which occupants are subjected
during an accident.
SRS warning lamp G
WARNING
If SRS is malfunctioning, individual systems
may
be triggered unintentionally or might not
be triggered in the event of an accident with
a high rate of vehicle deceleration.
A malfunction has occurred if:
R the 6 SRS warning lamp does not light
up when the ignition is switched on.
R the engine is running and the 6 SRS
warning lamp does not go out after a few
seconds.
R the engine is running and the 6 SRS
warning lamp lights up again.
In this case, have SRS checked immediately
at a qualified specialist workshop.
The 6 SRS warning lamp in the instrument
cluster lights up when the ignition is switched
on. It goes out no later than a few seconds
after the engine is started.
SRS functions are checked regularly when the
ignition is switched on or the engine is run-
ning. Therefore, malfunctions can be detec-
ted in good time. Triggering of belt tensioners and air-
bags During the first stage of a collision, the airbag
control unit evaluates important physical
data

relating to vehicle deceleration or accel-
eration, such as:
R duration
R direction
R magnitude
Based on the evaluation of this data, the air-
bag control unit pre-emptively triggers the
belt tensioners in the first stage.
If there is an even higher rate of vehicle decel-
eration or acceleration in a longitudinal direc-
tion, the front airbags are also deployed.
Your vehicle has adaptive, two-stage front air-
bags. The airbag control unit evaluates vehi-
cle deceleration or acceleration in the event
of a collision. In the first deployment stage,
the front airbag is filled with enough propel-
lant gas to reduce the risk of injuries. The
front airbag is fully deployed if a second
deployment threshold is reached within a few
milliseconds.
The belt tensioner and airbag triggering
thresholds are variable and are adapted to the
detected rate of deceleration or acceleration
of the vehicle. This process is pre-emptive in
nature. The triggering process must take
place in good time at the start of the collision.
The rate of vehicle deceleration or accelera-
tion and the direction of the force are essen-
tially determined by:
R the distribution of forces during the colli-
sion
R the collision angle
R the deformation characteristics of the vehi-
cle
R the characteristics of the object with which
the vehicle has collided
Factors which can only be seen and measured
after a collision has occurred do not play a
decisive role in the deployment of an airbag, Occupant safety
41
Safety Z

the driver and the front passenger have fas-
tened their seat belts.
i
For more information on the 7 seat
belt warning lamp, see "Warning and indi-
cator
lamps in the instrument cluster, seat
belt" ( Y page 257).
Rear seat belt status indicator Example: rear seat belt status indicator
The rear-compartment seat belt status indi-
cator

indicates the rear seat on which the belt
is fastened. In the example, the occupant on
the right rear seat, when viewed in the direc-
tion of travel, is secured. The ü symbol in
the display indicates a fastened seat belt. If a
seat belt is not fastened or if a seat is not
occupied, the ý symbol is displayed.
The rear-compartment seat belt status indi-
cator appears in the multifunction display for
around 30 seconds if:
R you drive off and reach a speed of approx-
imately 10 km/h.
R the rear passengers fasten or unfasten
their seat belts while the vehicle is in
motion.
R someone gets in or out of the vehicle and
the vehicle drives off again.
You can also cancel the rear seat belt status
indicator immediately ( Y page 229).
i The status indicator for the rear-compart-
ment seat belts is only available for certain
countries.
Belt tensioners, belt force limiters G
WARNING
If the seat belt tensioners have been trig-
gered, they provide no additional protection in the event of another accident. Therefore,
have belt tensioners which have been trig-
gered replaced at a qualified specialist work-
shop.
Comply with safety regulations when dispos-
ing of belt tensioners. Any Mercedes-Benz
Service Centre can provide details of these
regulations.
! If the front-passenger seat is not occu-
pied,

do not engage the seat belt tongue in
the buckle on the front-passenger seat.
Otherwise, the belt tensioner could be trig-
gered in the event of an accident.
The front seat belts and the outer seat belts
in the rear are equipped with belt tensioners
and belt force limiters.
The belt tensioners tighten the seat belts in
an accident, pulling them close against the
body.
Belt tensioners do not correct incorrect seat
positions or incorrectly fastened seat belts.
Belt tensioners do not pull vehicle occupants
back towards the backrest.
The belt tensioners can only be activated
when:
R the ignition is switched on.
R the restraint systems are operational; see
"6 SRS warning lamp" (Y page 41).
R the belt tongue is engaged in the buckle on
each of the front seat belts.
The belt tensioners on the outside seats in the
rear compartment are triggered independ-
ently of the lock status of the seat belts.
The belt tensioners are triggered depending
on the type and severity of an accident:
R if, in the event of a head-on or rear-end col-
lision the vehicle decelerates or acceler-
ates rapidly in a longitudinal direction dur-
ing the initial stages of the impact
R if, in the event of a side impact, on the side
opposite the impact the vehicle deceler- Occupant safety
49
Safety Z

teristics may be severely impaired. Addition-
ally, further driving safety systems are deac-
tivated.
There is an increased danger of skid-
ding and accidents.
Drive on carefully. Have ABS checked imme-
diately at a qualified specialist workshop.
If ABS is malfunctioning, other systems,
including driving safety systems, will also
become inoperative. Observe the information
on the ABS warning lamp ( Y page 258) and
display messages which may be shown in the
instrument cluster (Y page 230).
ABS regulates brake pressure in such a way
that the wheels do not lock when you brake.
This allows you to continue steering the vehi-
cle when braking.
ABS works from a speed of about 8 km/h
upwards, regardless of road-surface condi-
tions. ABS works on slippery surfaces, even
when you only brake gently.
The ! ABS warning lamp in the instrument
cluster lights up when the ignition is switched
on. It goes out when the engine is running.
Braking X
If ABS intervenes:
continue to depress the
brake pedal with force until the braking sit-
uation is over.
X To make a full brake application:
depress the brake pedal with full force.
If ABS intervenes when braking, you will feel
a pulsing in the brake pedal.
The pulsating brake pedal can be an indica-
tion of hazardous road conditions, and func-
tions as a reminder to take extra care while
driving. BAS (Brake Assist)
i Observe

the "Important safety notes" sec-
tion (Y page 61). G
WARNING
If BAS is malfunctioning, the braking distance
in an emergency braking situation is
increased. There is a risk of accident.
In an emergency braking situation, depress
the brake pedal with full force. ABS prevents
the wheels from locking.
BAS operates in emergency braking situa-
tions.

If you depress the brake pedal quickly,
BAS automatically boosts the braking force,
thus shortening the stopping distance.
The brakes will function as usual once you
release the brake pedal. BAS is deactivated. COLLISION PREVENTION ASSIST
General notes COLLISION PREVENTION ASSIST consists of
the adaptive Brake Assist and the distance
warning signal, which are described in the
following.
Distance warning function
Important safety notes
i
Observe

the "Important safety notes" sec-
tion for driving safety systems
(Y page 61). G
WARNING
The distance warning function does not react:
R to people or animals
R to oncoming vehicles
R to crossing traffic
R when cornering
Thus, the distance warning function cannot
provide a warning in all critical situations.
There is a risk of an accident.
Always

pay careful attention to the traffic sit-
uation and be ready to brake. 62
Driving safety systems
Safety

G
WARNING
The distance warning function cannot always
clearly identify objects and complex traffic
situations.
In such cases, the distance warning function
may:
R give an unnecessary warning
R not give a warning
There is a risk of an accident.
Always
pay careful attention to the traffic sit-
uation; do not rely on the distance warning
function alone.
Function
X To activate/deactivate:
activate or deac-
tivate the distance warning function in the
on-board computer (Y page 218).
Vehicles with a black and white multi-
function
display: when the distance warning
function is activated, the Ä symbol
appears in the status overview in the multi-
function display.
Vehicles with a colour multifunction dis-
play: when the distance warning function is
deactivated, the æ symbol appears in the
assistance graphics in the multifunction dis-
play.
The distance warning function can help you
to minimise the risk of a front-end collision
with a vehicle ahead or reduce the effects of
such a collision. If the distance warning func-
tion detects that there is a risk of a collision,
you will be warned visually and acoustically.
Without your intervention, the distance warn-
ing function cannot prevent a collision.
The distance warning function issues a warn-
ing at speeds:
R of around 30 km/h or more, if, over several
seconds, the distance maintained to the
vehicle travelling in front is insufficient. The
· distance warning lamp then lights up
in the instrument cluster.
R of around 7 km/h or higher, if you very
quickly approach a vehicle in front. An
intermittent warning tone will then sound, and the · distance warning lamp will
light up in the instrument cluster.
X Brake immediately in order to increase the
distance from the vehicle in front.
or
X Take evasive action provided it is safe to do
so.
Due to the nature of the system, particularly
complicated but non-critical driving condi-
tions

may also cause the system to display a
warning.
With the help of the radar sensor system, the
distance warning function can detect obsta-
cles that are in the path of your vehicle for an
extended period of time.
Up to a speed of around 70 km/h, the dis-
tance warning function can also react to sta-
tionary obstacles, such as stopped or parked
vehicles.
If you approach an obstacle and the distance
warning function detects a risk of a collision,
the system will alert you both visually and
acoustically.
In particular, the detection of obstacles can
be impaired in the case of:
R dirt on the sensors or obscured sensors
R snow or heavy rain
R interference by other radar sources
R strong radar reflections, for example, in
multi-storey car parks
R a narrow vehicle travelling in front, e.g. a
motorcycle
R a vehicle travelling in front on a different
line
Following damage to the front end of the vehi-
cle, have the configuration and operation of
the radar sensor checked at a qualified spe-
cialist workshop. This also applies to colli-
sions at slow speeds where there is no visible
damage to the front of the vehicle. Driving safety systems
63Safety Z