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Safety systems
Warning/
indicator
lampNSignal type
Possible causes/consequences and M
Solutions
$JN$ (USA only) or J(Canada only): the red brake system warning lamp
is lit while the engine is running.
A warning tone also sounds.
GWARNING
The brake boosting effect is malfunctioning and the braking characteristics
may be affected.
There is a risk of an accident.
XPull over and stop the vehicle safely as soon as possible, paying attention to
road and traffic conditions. Do not continue driving under any circumstan-
ces.
XSecure the vehicle against rolling away (Ypage 170).
XConsult a qualified specialist workshop.
XObserve the additional display messages in the multifunction display.
$JN $ (USA only) or J(Canada only): the red brake system warning lamp
is lit while the engine is running.
A warning tone also sounds.
There is not enough brake fluid in the brake fluid reservoir.
GWARNING
The braking effect may be impaired.
There is a risk of an accident.
XPull over and stop the vehicle safely as soon as possible, paying attention to
road and traffic conditions. Do not continue driving under any circumstan-
ces.
XSecure the vehicle against rolling away (Ypage 170).
XDo not add brake fluid. Adding more will not remedy the malfunction.
XConsult a qualified specialist workshop.
XObserve the additional display messages in the multifunction display.
$N USA only: the red brake system warning lamp is lit while the engine is
running. The multifunction display also shows a display message with the
# symbol.
The brake pads/linings have reached their wear limit.
XVisit a qualified specialist workshop.
Warning and indicator lamps in the instrument cluster287
On-board computer and displays
Z
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Warning/
indicator
lampNSignal type
Possible causes/consequences and M
Solutions
!NThe yellow ABS warning lamp is lit while the engine is running.
ABS (Anti-lock Braking System) is deactivated due to a malfunction. Therefore
BAS (Brake Assist), BAS PLUS with Cross-Traffic Assist, COLLISION PREVEN-
TION ASSIST PLUS, ESP
®(Electronic Stability Program), PRE‑SAFE®,
PRE‑SAFE®PLUS, PRE‑SAFE®Brake, the HOLD function, Hill Start Assist,
Crosswind Assist, STEER CONTROL, Active Lane Keeping Assist and Active
Blind Spot Assist are also deactivated.
ATTENTION ASSIST is deactivated.
GWARNING
The brake system continues to function normally, but without the functions
listed above. The wheels could therefore lock if you brake hard, for example.
The steerability and braking characteristics may be severely affected. The
braking distance in an emergency braking situation can increase.
If ESP
®is not operational, ESP®is unable to stabilize the vehicle.
There is an increased risk of skidding and an accident.
XObserve the additional display messages in the multifunction display.
XDrive on carefully.
XVisit a qualified specialist workshop.
If the ABS control unit is faulty, there is also a possibility that other systems,
such as the navigation system or the automatic transmission, will not be
available.
288Warning and indicator lamps in the instrument cluster
On-board computer and displays
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Warning/
indicator
lampNSignal type
Possible causes/consequences and M
Solutions
!NThe yellow ABS warning lamp is lit while the engine is running.
A warning tone also sounds.
EBD is not available due to a malfunction. Therefore ABS, BAS, BAS PLUS with
Cross-Traffic Assist, COLLISION PREVENTION ASSIST PLUS, ESP
®,
PRE‑SAFE®, PRE‑SAFE®PLUS, PRE‑SAFE®Brake, the HOLD function, Hill Start
Assist, Crosswind Assist, STEER CONTROL, Active Lane Keeping Assist and
Active Blind Spot Assist are also unavailable.
ATTENTION ASSIST is deactivated.
GWARNING
The brake system continues to function normally, but without the functions
listed above. The front and rear wheels could therefore lock if you brake hard,
for example.
The steerability and braking characteristics may be severely affected. The
braking distance in an emergency braking situation can increase.
If ESP
®is not operational, ESP®is unable to stabilize the vehicle.
There is an increased risk of skidding and an accident.
XObserve the additional display messages in the multifunction display.
XDrive on carefully.
XVisit a qualified specialist workshop.
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Warning/
indicator
lampNSignal type
Possible causes/consequences and M
Solutions
$J
÷!N$ (USA only), J(Canada only): the red brake warning lamp, the
yellow ESP®warning lamp and the yellow ABS warning lamp are lit while the
engine is running.
ABS and ESP
®are not available due to a malfunction. Therefore BAS, BAS
PLUS with Cross-Traffic Assist, COLLISION PREVENTION ASSIST PLUS, EBD,
PRE‑SAFE
®, PRE‑SAFE®PLUS, PRE‑SAFE®Brake, the HOLD function, Hill Start
Assist, Crosswind Assist, STEER CONTROL, Active Lane Keeping Assist and
Active Blind Spot Assist are also unavailable.
ATTENTION ASSIST is deactivated.
GWARNING
The brake system continues to function normally, but without the functions
listed above. The front and rear wheels could therefore lock if you brake hard,
for example.
The steerability and braking characteristics may be severely affected. The
braking distance in an emergency braking situation can increase.
If ESP
®is not operational, ESP®is unable to stabilize the vehicle.
There is an increased risk of skidding and an accident.
XObserve the additional display messages in the multifunction display.
XDrive on carefully.
XVisit a qualified specialist workshop.
÷N The yellow ESP®warning lamp flashes while the vehicle is in motion.
ESP
®or traction control has intervened because there is a risk of skidding or
at least one wheel has started to spin.
Cruise control or DISTRONIC PLUS is deactivated.
XWhen pulling away, only depress the accelerator pedal as far as necessary.
XEase off the accelerator pedal while the vehicle is in motion.
XAdapt your driving style to suit the road and weather conditions.
XDo not deactivate ESP®.
In rare cases (
Ypage 74), it may be best to deactivate ESP®.
Observe the important safety notes on ESP
®(Ypage 73).
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On-board computer and displays
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Warning/
indicator
lampNSignal type
Possible causes/consequences and M
Solutions
÷NThe yellow ESP®warning lamp is lit while the engine is running.
ESP
®, BAS, BAS PLUS with Cross-Traffic Assist, COLLISION PREVENTION
ASSIST PLUS, PRE ‑SAFE®, PRE‑SAFE®PLUS, PRE‑SAFE®Brake, the HOLD
function, Hill Start Assist, Crosswind Assist, STEER CONTROL, Active Lane
Keeping Assist and Active Blind Spot Assist are unavailable due to a malfunc-
tion.
ATTENTION ASSIST is deactivated.
GWARNING
The brake system continues to function normally, but without the functions
listed above.
The braking distance in an emergency braking situation can thus increase.
If ESP
®is not operational, ESP®is unable to stabilize the vehicle.
There is an increased risk of skidding and an accident.
XObserve the additional display messages in the multifunction display.
XDrive on carefully.
XVisit a qualified specialist workshop.
åN The yellow ESP®OFF warning lamp is lit while the engine is running.
ESP
®is deactivated.
GWARNING
If ESP®is switched off, ESP®is unable to stabilize the vehicle.
Further driving systems or driving safety systems are thus restricted, e.g.
Active Blind Spot Assist. The system does not perform course-correcting
brake applications.
There is an increased risk of skidding and an accident.
XReactivate ESP®.
In rare cases (
Ypage 74), it may be best to deactivate ESP®.
Observe the important safety notes on ESP
®(Ypage 73).
XAdapt your driving style to suit the road and weather conditions.
If ESP
®cannot be activated:
XDrive on carefully.
XHave ESP®checked at a qualified specialist workshop.
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Warning/
indicator
lampNSignal type
Possible causes/consequences and M
Solutions
F!NF (USA only) or !(Canada only): the red indicator lamp for the
electric parking brake flashes or is lit and/or the yellow warning lamp for the
electric parking brake is lit.
XObserve the additional display messages in the multifunction display.
6N The red restraint system warning lamp is lit while the engine is running.
The restraint system is faulty.
GWARNING
The air bags or Emergency Tensioning Devices may either be triggered unin-
tentionally or, in the event of an accident, may not be triggered.
There is an increased risk of injury.
XObserve the additional display messages in the multifunction display.
XDrive on carefully.
XHave the restraint system checked at a qualified specialist workshop imme-
diately.
For further information about the restraint system, see (
Ypage 44).
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On-board computer and displays
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Engine
Warning/
indicator
lampNSignal type
Possible causes/consequences and M
Solutions
;NThe yellow Check Engine warning lamp lights up while the engine is running.
There may be a malfunction, for example:
Rin the engine management
Rin the fuel injection system
Rin the exhaust system
Rin the ignition system
Rin the fuel system
The emission limit values may be exceeded and the engine may be in emer-
gency mode.
XHave the vehicle checked as soon as possible at a qualified specialist work-
shop.
iIn some states, you must immediately visit a qualified specialist workshop
as soon as the yellow Check Engine warning lamp lights up. This is due to the
legal requirements in effect in these states. If in doubt, check whether such legal regulations apply in the state in which you are currently driving.
8N The yellow reserve fuel warning lamp lights up while the engine is running.
The fuel level has dropped into the reserve range.
XRefuel at the nearest gas station.
8N The yellow reserve fuel warning lamp flashes while the vehicle is in motion.
In addition, the ;Check Engine warning lamp may light up.
The fuel system pressure is too low. The fuel filler cap is not closed correctly
or the fuel system is leaking.
XCheck that the fuel filler cap is correctly closed.
XIf the fuel filler cap is not correctly closed: close the fuel filler cap.
XIf the fuel filler cap is closed:visit a qualified specialist workshop.
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On-board computer and displays
Z
Page 296 of 410
Warning/
indicator
lampNSignal type
Possible causes/consequences and M
Solutions
?NThe red coolant warning lamp lights up while the engine is running and the
coolant temperature gage is at the start of the bar display.
The temperature sensor for the coolant temperature gage is defective.
The coolant temperature is no longer being monitored. There is a risk of engine
damage if the coolant temperature is too high.
XPull over and stop the vehicle safely and switch off the engine, paying
attention to road and traffic conditions. Do not continue driving under any
circumstances.
XSecure the vehicle against rolling away (Ypage 170).
XConsult a qualified specialist workshop.
294Warning and indicator lamps in the instrument cluster
On-board computer and displays