2008 MERCEDES-BENZ B-CLASS HATCHBACK light switch

Troubleshooting
222 Troubleshooting
Points to remember
G
Risk of accident and injury
The operating safety of your vehicle could be compromised if service work is carried out improperly. You could lose control of the vehicle,
thereby causing an accident. Safety systems may also not be able to protect you or others as intended.
Always have maintenance work carried out at a qualified specialist workshop which has the necessary specialist knowledge and tools to
carry out the work required.
Mercedes-Benz recommends that you use a Mercedes-Benz Service Centre for this purpose.
In particular, work relevant to safety or on safety-related systems must be carried out at a qualified specialist workshop. Warning and indicator lamps in switches and buttons
Problem Possible cause/consequence Suggested solutions
One or all of the indicator lamps
in the seat heating* button are
flashing. The seat heating* has
switched itself off automatically. The on-board voltage is too low,
because too many consumers are
switched on. X
Switch off consumers that are not required, e. g. reading lamp or
interior lighting.
Once the battery is sufficiently charged, the seat ventilation* will
switch back on automatically. The indicator lamp in the
2
button on the air-conditioning */
Ther motronic* control panel
lights up. The cooling system can-
not be switched on. Cooling has been deactivated
due to a malfunction. X
Visit a qualified specialist workshop. Practical advice
* optional
245_AKB; 2; 7, en-GB
wdomann,
Version: 2.11.4 2008-10-17T11:22:31+02:00 - Seite 222Dateiname: 6515_1640_02_buchblock.pdf; preflight

Troubleshooting
223Problem Possible cause/consequence Suggested solutions
The indicator lamp in the
F/
1 rear-window heating button
is flashing. The rear-window heat-
ing has switched itself off prema-
turely or cannot be switched on. The on-board voltage is too low,
because too many consumers are
switched on. X
Switch off consumers that are not required, e. g. reading lamp or
interior lighting.
Once the battery is sufficiently charged, the rear window heating
will switch back on automatically. Vehicles with automatic child
seat recognition on the front-
passenger seat:
The
5 PASSENGER AIRBAG
OFF warning lamp on the centre
console is lit. A special Mercedes-Benz child
seat with automatic child seat
recognition has been fitted to the
front-passenger seat. The front-
passenger airbag has therefore
been disabled as desired.
G
Risk of injury
There is no child seat fitted to the
front-passenger seat. The auto-
matic child seat recognition is
malfunctioning. X
Remove electronic equipment from the front-passenger seat, for
example
R
notebook
R mobile phone
R cards with transponders, e.g. ski passes or access passes
If the 5 PASSENGER AIRBAG OFF warning lamp is still lit:
X Visit a qualified specialist workshop. You have started the engine with
the key. The indicator lamp in the
ECO start/stop function* button
does not light up or goes out
again after a short time. You have deactivated the ECO
start/stop function*. X
Activate the ECO start/stop function* again. The ECO start/stop function*is
not available due to a fault. X
Visit a qualified specialist workshop. Practical advice
* optional
245_AKB; 2; 7, en-GB
wdomann,
Version: 2.11.4
2008-10-17T11:22:31+02:00 - Seite 223 ZDateiname: 6515_1640_02_buchblock.pdf; preflight

Troubleshooting
224 Warning and indicator lamps in the instrument cluster
Problem Possible cause/consequence Suggested solutions
-
The yellow ABS warning
lamp comes on while the
engine is running. G
Risk of accident
ABS (Anti-lock Brake System) is
deactivated due to a fault. There-
fore, ESP ®
(Electronic Stability
Program), BAS (Brake Assist), the
steering assistant STEER CON-
TROL, the hill start assist and the
tyre pressure loss warning sys-
tem are also deactivated.
The brake system continues to
function normally, but without
electronic support. The wheels
could therefore lock if you brake
hard.
If the ABS control unit is faulty,
other systems may also not be
available: e.g. Parktronic sys-
tem*, the navigation system* or
the Autotronic*. X
Drive on carefully.
X Observe the additional messages in the multi-function display
(Y page 202).
X Visit a qualified specialist workshop. -
The yellow ABS warning
lamp comes on while the
engine is running. G
Risk of accident
The on-board voltage is too low.
ABS has been deactivated due to
undervoltage. X
Switch off consumers that are not required, e g. reading lamps or
interior lighting.
ABS will be available again as soon as the vehicle's electrical sys-
tem voltage increases. Practical advice
* optional
245_AKB; 2; 7, en-GB
wdomann,
Version: 2.11.4 2008-10-17T11:22:31+02:00 - Seite 224Dateiname: 6515_1640_02_buchblock.pdf; preflight

Troubleshooting
230 Warning tones
Problem Possible cause/consequence Suggested solutions
The anti-theft warning alarm* is
triggered. You have opened the vehicle with
the anti-theft alarm system still
activated*. X
Switch off the alarm (Y page 57).You hear a warning tone. A message appears in the multi-
function display. X
See the explanations for the display message (Y page 202). You are driving with the parking
brake applied. X
Release the parking brake. The light is switched on when you
leave the vehicle. X
Turn the light switch to MorU.
or
X If the rear foglamp is switched on: press the light switch in to the
stop. G
Risk of injury
The driver or front passenger has
not fastened their seat belt X
Fasten your seat belt (Y page 72).Practical advice
* optional
245_AKB; 2; 7, en-GB
wdomann,
Version: 2.11.4 2008-10-17T11:22:31+02:00 - Seite 230Dateiname: 6515_1640_02_buchblock.pdf; preflight

Troubleshooting
231Problem Possible cause/consequence Suggested solutions
You hear a warning tone.
Vehicles with AUTOTRONIC*:
You have:
R
switched off the engine
R opened the driver's door
R not moved the selector lever to
position P X
Move the selector lever to P.Accident
Problem Possible cause/consequence Suggested solutions
Fuel is leaking from the vehicle.
G
Risk of fire
The fuel line or the fuel tank has
been damaged. The leaking fuel
creates a risk of fire or explosion. X
Switch off the ignition immediately.
X Remove the ignition key.
Do not restart the engine under any circumstances. The leaking fuel
creates a risk of fire or explosion.
X Consult a qualified specialist workshop. You are unable to determine the
extent of the damage. X
Consult a qualified specialist workshop. You cannot detect any damage. X
Start the engine as normal. Practical advice
* optional
245_AKB; 2; 7, en-GB
wdomann,
Version: 2.11.4
2008-10-17T11:22:31+02:00 - Seite 231 ZDateiname: 6515_1640_02_buchblock.pdf; preflight

Troubleshooting
232 Fuel and fuel tank
Problem Possible cause/consequence Suggested solutions
Fuel is leaking from the vehicle.
G
Risk of explosion or fire
The fuel line or the fuel tank is
defective. X
Turn the key to position 0(Y page 62) in the ignition lock immedi-
ately and remove it.
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 released. X
Unlock the vehicle ( Ypage 241).
or
X Unlock the vehicle manually (Y page 242). The opening mechanism is jam-
med. X
Consult a qualified specialist workshop. The fuel tank in a diesel engine
vehicle has been run completely
dry and the engine will not start. There is air in the fuel system. X
Refuel the vehicle.
X Switch on the ignition for approximately 10 seconds (key in posi-
tion 2(Y page 62) in the ignition lock).
X Start the engine continuously for up to 40 seconds until it runs
smoothly.
The fuel system is now free of air.
If the engine does not start:
X Wait two minutes.
X Repeat the starting procedure for up to 40 seconds.
If the engine still does not start:
X Consult a qualified specialist workshop. Practical advice
245_AKB; 2; 7, en-GB
wdomann,
Version: 2.11.4 2008-10-17T11:22:31+02:00 - Seite 232Dateiname: 6515_1640_02_buchblock.pdf; preflight

Troubleshooting
236 Parktronic*
Problem Possible cause/consequence Suggested solutions
Only the red segments in the
Parktronic warning display are lit.
You also hear a warning tone for
approximately two seconds.
Parktronic is deactivated after
approximately 20 seconds and
the indicator lamp in the Park-
tronic button lights up. Parktronic has malfunctioned
and has switched itself off. X
If problems persist, have Parktronic checked at a qualified spe-
cialist workshop. Only the red segments in the
Parktronic warning display are lit.
Parktronic is deactivated after
approximately 20 seconds. The Parktronic sensors are dirty
or there is interference. X
Clean the Parktronic sensors ( Ypage 196).
X Switch the ignition back on. Only the red segments in the
Parktronic warning display are lit.
Parktronic is deactivated after
approximately 20 seconds. The problem may be caused by an
external source of radio or ultra-
sound waves. X
See if Parktronic functions in a different location. Practical advice
* optional
245_AKB; 2; 7, en-GB
wdomann,
Version: 2.11.4 2008-10-17T11:22:31+02:00 - Seite 236Dateiname: 6515_1640_02_buchblock.pdf; preflight

Troubleshooting
237Headlamps
Problem Possible cause/consequence Suggested solutions
The headlamps or the turn signals
in the exterior mirrors are misted
up on the inside. Air humidity is very high. X
Drive with the headlamps switched on.
The headlamps are demisted after a short distance. The headlamp housing is not
sealed and moisture has been
able to enter. X
Have the headlamps checked at a qualified specialist workshop. Windscreen wipers
Problem Possible cause/consequence Suggested solutions
The windscreen wipers are jam-
med. Leaves or snow, for example, may
be obstructing the windscreen
wiper movement. The wiper
motor has been deactivated. X
For safety reasons, you should remove the key from the ignition
lock.
X Remove the cause of the obstruction.
X Switch the windscreen wipers back on. The windscreen wipers fail com-
pletely. G
Risk of accident
The windscreen wiper drive is
malfunctioning. X
Select another wiper speed on the combination switch.
X Have the windscreen wipers checked at a qualified specialist work-
shop. Practical advice
245_AKB; 2; 7, en-GB
wdomann,
Version: 2.11.4
2008-10-17T11:22:31+02:00 - Seite 237 ZDateiname: 6515_1640_02_buchblock.pdf; preflight