sensor MERCEDES-BENZ A-CLASS HATCHBACK 2012 Service Manual

Display messages
Possible causes/consequences and
M
MSolutions Blind Spot Assist is temporarily inoperative. Possible causes:
R the sensors are dirty.
R the function is impaired due to heavy rain or snow.
R the radar sensor system is outside the operating temperature
range.
R the radar sensor system is temporarily inoperative, e.g. due to
electromagnetic radiation emitted by nearby TV or radio sta-
tions or other sources of electromagnetic radiation.
The yellow 9indicator lamps also light up in the exterior mir-
rors.
Once the causes listed above no longer apply, the display message goes out.
Blind Spot Assist is operational again.
If the display message does not disappear:
X Pull over and stop the vehicle safely as soon as possible, paying
attention to road and traffic conditions.
X Secure the vehicle against rolling away (Y page 162).
X Clean the sensors (Y page 294).
X Restart the engine. Blind Spot Assist Blind Spot Assist
inoperative inoperative Blind Spot Assist is faulty.
The yellow
9indicator lamps also light up in the exterior mir-
rors.
X Visit a qualified specialist workshop. Park Park
Assist
Assist cancel‐
cancel‐
led
led The driver's door is open and the driver's seat belt has not been
fastened.
X Repeat the parking process with the seat belt fastened and the
driver's door closed. You inadvertently touched the multifunction steering wheel while
steering intervention was active.
X While steering intervention is active, make sure not to touch the
multifunction steering wheel. The vehicle has started to skid and ESP
®
has intervened.
X Use Active Parking Assist again later (Y page 186).248
Display
messagesOn-board computer and displays

Display messages
Possible causes/consequences and
M
MSolutions Park
Park
Assist
Assist inoper‐
inoper‐
ative
ative You have just carried out a large number of turning or parking
manoeuvres.
Active Parking Assist will become available again after approx-
imately ten minutes (Y
page 186).
X Pull over and stop the vehicle safely as soon as possible, paying
attention to road and traffic conditions.
X Switch off and restart the engine.
If the display message continues to be displayed: X Visit a qualified specialist workshop. PARKTRONIC is faulty.
X Visit a qualified specialist workshop. DISTRONIC PLUS off DISTRONIC PLUS off DISTRONIC PLUS has been deactivated (Y
page 173). If it was
deactivated automatically, a warning tone also sounds. DISTRONIC PLUS
DISTRONIC PLUS
available again available again DISTRONIC PLUS is operational again after having been tempo-
rarily unavailable. You can now reactivate DISTRONIC PLUS
(Y
page 173). DISTRONIC DISTRONIC
PLUS
PLUScur‐
cur‐
rently
rently unavailable
unavailable
See Owner's Manual
See Owner's Manual DISTRONIC PLUS is temporarily inoperative. Possible causes:
R the function is impaired due to heavy rain or snow.
R the sensors in the radiator trim are dirty
R the radar sensor system is temporarily inoperative, e.g. due to
electromagnetic radiation emitted by nearby TV or radio sta-
tions or other sources of electromagnetic radiation.
R the system is outside the operating temperature range.
R the on-board voltage is too low.
A warning tone also sounds.
Once the causes listed above no longer apply, the display message goes out.
DISTRONIC is operational again.
If the display message does not disappear:
X Pull over and stop the vehicle safely as soon as possible, paying
attention to road and traffic conditions.
X Secure the vehicle against rolling away (Y page 162).
X Clean the sensors in the radiator trim (Y page 294).
X Restart the engine. Display
messages
249On-board computer and displays Z

Engine
Problem
Possible causes/consequences and
M
MSolutions ;
The yellow engine diag-
nostics warning lamp
lights up while the
engine is running. There may be a fault, for example:
R in the engine management
R in the fuel injection system
R in the exhaust system
R in the ignition system (for vehicles with petrol engines)
R in the fuel system
The emission limit values may be exceeded and the engine may be running in emergency mode.
X Have the vehicle checked as soon as possible at a qualified
specialist workshop. Vehicles with a diesel engine: the fuel tank has been run dry
(Y
page 161).
X Start the engine three to four times after refuelling.
If the yellow engine diagnostics warning lamp goes out, emer-
gency running mode is cancelled. The vehicle need not be
checked. æ
The yellow reserve fuel
warning lamp lights up
while the engine is run-
ning.
The fuel level has dropped into the reserve range.
Operation of the auxiliary heating is deactivated when the fuel level drops into the reserve range.
X Refuel at the nearest filling station. ?
The red coolant warn-
ing lamp lights up while
the engine is running
and the coolant tem-
perature gauge is at the start of the scale. The temperature sensor for the coolant temperature gauge is
faulty.
The coolant temperature is no longer being monitored. There is a risk of engine damage if the coolant temperature is too high.
X Stop the vehicle immediately, paying attention to road and traf-
fic conditions, and switch off the engine. Do not continue driving
under any circumstances.
X Secure the vehicle against rolling away (Y page 162).
X Consult a qualified specialist workshop. 264
Warning and indicator lamps in the instrument clusterOn-board computer and displays

Cleaning the mirror turn signal
!
Only use cleaning agents or cleaning
cloths that are suitable for plastic lenses.
Unsuitable cleaning agents or cleaning
cloths could scratch or damage the plastic lenses of the mirror turn signals.
X Clean the plastic lenses of the mirror turn
signals in the exterior mirror housing using
a wet sponge and a mild cleaning agent,
e.g. Mercedes-Benz car shampoo or clean-
ing cloths.
Cleaning the sensors !
If you clean the sensors with a high-pres-
sure cleaner, make sure that you keep a
distance of at least 30 cm between the
vehicle and the high-pressure cleaner noz-
zle. Information about the correct distance is available from the equipment manufac-
turer. X
Clean sensors :of the driving systems
with water, car shampoo and a soft cloth.
Cleaning the reversing camera !
Do not clean the camera lens and the area
around the reversing camera with a high-
pressure cleaner. X
Use clear water and a soft cloth to clean
camera lens :.
Cleaning the exhaust tail pipes Impurities combined with the effects of road
grit and corrosive environmental factors may cause flash rust to form on the surface. You
can restore the original shine of the exhaust
pipe by cleaning it regularly, especially in win-
ter and after washing.
! Do not clean the exhaust pipe with acid-
based cleaning agents such as sanitary
cleansers or wheel cleaners.
X Clean the exhaust pipe with a care product
tested and approved by Mercedes-Benz.
! AMG vehicles with black exhaust pipes:
do not use chrome polish to polish black
chromed screens. They will otherwise lose
their silky black shine. Rub the screen using
a lightly oiled cloth after every car wash.
Commercially available engine oils, WD 40
or Ballistol are suitable oils.
Cleaning the trailer tow hitch H
Environmental note
Dispose of oily and greasy cloths in an envi-
ronmentally-responsible manner.
! Do not clean the ball coupling with a high-
pressure cleaner. Do not use solvents.
! Observe the note on care provided by the
trailer manufacturer. 294
CareMaintenance and care

Useful information
............................336
Information on technical data .........336
Vehicle electronics ...........................336
Identification plates .........................338
Service products and capacities .....338
Vehicle data ...................................... 346
Trailer tow hitch ................................ 348
24 GHz radar sensor system (coun-
try overview) ..................................... 350 335Technical data

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). Information on technical data
You can find technical data on the Internet at: http://www.mercedes-benz.com
i The technical data was determined in
accordance with EC Directives. All data
applies to the vehicle's standard equip-
ment. It may therefore differ for vehicles
with optional equipment. You can obtain
further information from a Mercedes-Benz
Service Centre. Vehicle electronics
Tampering with the engine electron-
ics
! Only have work carried out on the engine
electronics and its associated parts, such
as control units, sensors and connector
leads, at a qualified specialist workshop.
Vehicle components may otherwise wear
more quickly and the vehicle's operating
permit may be invalidated. Retrofitting two-way radios and
mobile phones (RF transmitters)
G
WARNING
If RF transmitters are tampered with or not
properly retrofitted, the electromagnetic radi- ation they emit can interfere with the vehicle
electronics. This may jeopardise the opera-
tional safety of the vehicle. There is a risk of an accident.
You should have all work on electrical and
electronic components carried out at a quali-
fied specialist workshop. G
WARNING
If you use the RF transmitter in the vehicle in
an improper way, its electromagnetic radia-
tion can disrupt vehicle electronics, e.g. if:
R the RF transmitter is not connected to an
exterior aerial
R the exterior aerial is fitted incorrectly or is
not a low-reflection aerial
This can jeopardise the operating safety of the vehicle. There is a risk of an accident.
Have the low-reflection exterior aerial fitted at
a qualified specialist workshop. When oper-
ating in the vehicle, always connect the RF
transmitter to the low-reflection exterior aer-
ial.
! The operating permit may be invalidated if
the instructions for installation and use of
RF transmitters are not observed.
In particular, the following conditions must be complied with:
R only approved wavebands may be used.
R observe the maximum permissible out-
put in these wavebands.
R only approved aerial positions may be
used.
Observe the notes on operating mobile
phones (Y page 279).
The following aerial positions may be used for
the correct installation of RF transmitters: 336
Vehicle electronicsTechnical data

clean the antifreeze from components before
starting the engine.
! Only add coolant that has been premixed
with the desired antifreeze protection. You
could otherwise damage the engine.
Further information on coolants can be
found in the Mercedes-Benz Specifications for Service Products, MB Specifications for
Service Products 310.1, e.g. on the Inter-
net at http://bevo.mercedes-benz.com.
Or contact a qualified specialist workshop.
! Always use a suitable coolant mixture,
even in countries where high temperatures prevail.
Otherwise, the engine cooling system is not
sufficiently protected from corrosion and
overheating.
! The engine cooling system is filled with
coolant, which must be renewed after
15 years or after 250,000 kilometres at the
latest.
When handling coolant, observe the impor-
tant safety notes on service products
(Y page 338).
The coolant is a mixture of water and anti-
freeze/corrosion inhibitor. It performs the
following tasks:
R anti-corrosion protection
R antifreeze protection
R raising the boiling point
If antifreeze/corrosion inhibitor is present in
the correct concentration, the boiling point of
the coolant during operation will be approx-
imately 130 †.
The antifreeze/corrosion inhibitor concentra- tion in the engine cooling system should:
R be at least 50%. This will protect the engine
cooling system against freezing down to
approximately -37 †.
R not exceed 55% (antifreeze protection
down to -45 †). Heat will otherwise not be
dissipated as effectively. If the vehicle has lost coolant, top it up with
equal amounts of water and antifreeze/
corrosion inhibitor.
Mercedes-Benz recommends an antifreeze/
corrosion inhibitor concentrate in accord-
ance with MB Specifications for Service Prod- ucts 310.1.
The coolant is checked at every maintenance
interval at a qualified specialist workshop.
i When the vehicle is first delivered, it is fil-
led with a coolant mixture that ensures
adequate antifreeze and corrosion protec-
tion. Windscreen washer system and head-
lamp cleaning system
Important safety notes G
WARNING
Windscreen washer concentrate is highly
flammable. If it comes into contact with hot
engine components or the exhaust system it
could ignite. There is a risk of fire and injury.
Make sure that no windscreen washer con-
centrate is spilled next to the filler neck.
! Only use washer fluid that is suitable for
plastic lamp lenses, e.g. MB SummerFit or
MB WinterFit. Unsuitable washer fluid
could damage the plastic lenses of the
headlamps.
! Do not use distilled or de-ionised water in
the washer fluid reservoir. Otherwise, the
level sensor may be damaged.
! Only the washer fluids SummerFit and
WinterFit can be mixed. Otherwise, the
spraying nozzles could become blocked.
When handling washer fluid, observe the
important safety notes on service products
(Y page 338). Service products and capacities
345Technical data Z

Permissible
trailer load,
braked 18 Permissible
trailer load,
braked 19 Permissible
trailer load, unbraked Maximum
drawbar nose-
weight 20 Permissible
rear axle
load when towing a trailer A 180
21 1500 kg 1200 kg 695 kg 75 kg 955 kg
A 200
21 1500 kg 1400 kg 695 kg 75 kg 950 kg
A 250
21 1500 kg 1500 kg 720 kg 75 kg 960 kg
A 180 CDI
21 1500 kg 1200 kg 735 kg 75 kg 950 kg
A 200 CDI
21 1500 kg 1500 kg 735 kg 75 kg 950 kg
A 220 CDI
21 1500 kg 1500 kg 740 kg 75 kg 950 kg
The actual noseweight may not be higher than the value which is given. The value can be found
on the trailer tow hitch or trailer identification plates. The lowest weight applies.
You can attach carrier systems, e.g. bicycle racks or load-bearing implements, on the ball
coupling. The maximum noseweight of 75 kg applies when using carrier systems on the ball
coupling. 24 GHz radar sensor system (country overview)
The 24 GHz radar sensor system requires separate approval for each country. When you are
driving in a country in which the radar sensor system is not approved, you must deactivate the
system using the on-board computer (Y page 223).
The current country overview can be obtained from a Mercedes-Benz Service Centre or on the
Internet at: http://www.mercedes-benz.de/betriebsanleitung.
Vehicles with a navigation system: the radar sensor system is deactivated automatically
near radio telescope facilities. A display message appears in the multifunction display to tell
you that the radar sensor system is being switched off (Y page 246).
If Blind Spot Assist is active, it will be deactivated automatically (Y page 219).
If deactivation does not occur automatically, you must deactivate the radar sensor system
using the on-board computer (Y page 223).
Vehicles without navigation and vehicles for Australia: you must deactivate the radar
sensor system using the on-board computer when you are near a radio telescope facility
(Y page 223).
18 At a minimum gradient-climbing capability of 8% from a standstill.
19 At a minimum gradient-climbing capability of 12% from a standstill.
20 The drawbar noseweight is not included in the trailer load.
21 BlueEFFICIENCY 350
24 GHz radar sensor system (country overview)Technical data