2015 MERCEDES-BENZ S-Class warning lights

Display messages
Possible causes/consequences and
M
MSolutions $(USA
only)J
(Canada
only)
Check Brake Fluid Check Brake Fluid
Level Level There is not enough brake fluid in the brake fluid reservoir.
In addition, the
$(USA only)/ J(Canada only) warning
lamp lights up in the instrument cluster and a warning tone
sounds.
G WARNING
The braking effect may be impaired.
There is a risk of an accident. X Pull over and stop the vehicle safely as soon as possible, paying
attention to road and traffic conditions. Do not continue driving
under any circumstances.
X Secure the vehicle against rolling away (Y page 220).
X Consult a qualified specialist workshop.
X Do not add brake fluid. This does not correct the malfunction. #
Check Brake Pad Check Brake Pad
Wear Wear The brake pads/linings have reached their wear limit.
USA only: the red
$brake system warning lamp also lights up
while the engine is running.
X Visit a qualified specialist workshop. G
Inoperative Inoperative One or more main features of the mbrace system are malfunc-
tioning.
X Have the mbrace system checked immediately at a qualified
specialist workshop. PRE-SAFE Inopera‐ PRE-SAFE Inopera‐
tive See Opera‐ tive See Opera‐
tor's Manual tor's Manual
Important functions of PRE-SAFE
®
have failed. All other occupant
safety systems, e.g. air bags, remain available.
X Visit a qualified specialist workshop immediately. 324
Display
messagesOn-board computer and displays

Display messages
Possible causes/consequences and
M
MSolutions The seat belt buckle extender on the right or left of the rear com-
partment is not in the predefined position. There is not enough belt slack in the system.
G WARNING
If the seat belt buckle extender is not in the predefined position,
the seat belt cannot provide the intended level of protection.
There is an increased risk of injury. X Loosen the seat belt.
X Repeat the seat belt fastening procedure. The seat belt buckle extender on the right or left of the rear com-
partment is not in the predefined position. The assistance meas-
ures specified have been carried out. There is still a malfunction.
G WARNING
If the seat belt buckle extender is not in the predefined position,
the seat belt cannot provide the intended level of protection.
There is an increased risk of injury. X Visit a qualified specialist workshop. 6
SRS Malfunction SRS Malfunction
Service Required Service Required The restraint system is faulty. The
6warning lamp also lights
up in the instrument cluster.
G WARNING
The air bags or Emergency Tensioning Devices may either be trig- gered unintentionally or, in the event of an accident, may not be
triggered.
There is an increased risk of injury.
X Visit a qualified specialist workshop.
For further information about the restraint system, see
(Y page 49). 6
Front Front
Left
LeftMalfunc‐
Malfunc‐
tion Service
tion Service
Required Required orFront
Front
Right Malfunction
Right Malfunction
Service Required Service Required The restraint system has malfunctioned at the front on the left or
right. The 6warning lamp also lights up in the instrument clus-
ter.
G WARNING
The air bags or Emergency Tensioning Devices may either be trig- gered unintentionally or, in the event of an accident, may not be
triggered.
There is an increased risk of injury.
X Visit a qualified specialist workshop. 328
Display
messagesOn-board computer and displays

Display messages
Possible causes/consequences and
M
MSolutions 6
Rear Left Malfunc‐ Rear Left Malfunc‐
tion Service tion Service
Required Required
orRear
Rear
Right Malfunction
Right Malfunction
Service Required Service Required The restraint system has malfunctioned at the rear on the left or
right. The 6warning lamp also lights up in the instrument clus-
ter.
G WARNING
The air bags or Emergency Tensioning Devices may either be trig- gered unintentionally or, in the event of an accident, may not be
triggered.
There is an increased risk of injury.
X Visit a qualified specialist workshop. 6
Rear Left Malfunc‐ Rear Left Malfunc‐
tion Service tion Service
Required Required
orRear
Rear
Right Malfunction
Right Malfunction
Service Required Service Required G
WARNING
If the seat belt buckle extender is not in the predefined position,
the seat belt cannot provide the intended level of protection.
There is an increased risk of injury. X Pull over and stop the vehicle safely as soon as possible, paying
attention to road and traffic conditions.
X Perform the specified assistance measures when display mes-
sage Check Left Rear Belt See Operator's Manual Check Left Rear Belt See Operator's Manual or
Check
Check Right
RightRear
RearBelt
Belt See
SeeOperator's
Operator's Manual
Manualis shown
(Y page 327).
If the display message does not disappear:
X Visit a qualified specialist workshop immediately. 6
Rear Center Mal‐ Rear Center Mal‐
function Service function Service
Required Required The restraint system has malfunctioned at the rear center. The
6 warning lamp also lights up in the instrument cluster.
G WARNING
The air bags or Emergency Tensioning Devices may either be trig- gered unintentionally or, in the event of an accident, may not be
triggered.
There is an increased risk of injury.
X Visit a qualified specialist workshop. Display
messages
329On-board computer and displays Z

Display messages
Possible causes/consequences and
M
MSolutions 6
Left Side Curtain Left Side Curtain
Airbag Airbag
Malfunction
Malfunction
Service Required
Service Required
or Right Side Cur‐ Right Side Cur‐
tain Airbag Mal‐
tain Airbag Mal‐
function Service function Service
Required Required There is a malfunction in the left-hand or right-hand window cur-
tain air bag. The
6warning lamp also lights up in the instrument
cluster.
G WARNING
The left or right window curtain air bag may either be triggered
unintentionally or, in the event of an accident, may not be trig-
gered.
There is an increased risk of injury. X Visit a qualified specialist workshop. 330
Display
messagesOn-board computer and displays

Display messages
Possible causes/consequences and
M
MSolutions b
Check Front Left Check Front Left
Parking Lamp Parking Lamp
or
Check Front Right
Check Front Right
Parking Lamp Parking Lamp The front left or front right parking or standing lamp is defective.
X Visit a qualified specialist workshop. b
Backup Light Backup Light The left or right-hand backup lamp is defective.
X Visit a qualified specialist workshop. b
Check Front Left Check Front Left
Sidemarker Lamp Sidemarker Lamp
or
Check Front Right
Check Front Right
Sidemarker Lamp Sidemarker Lamp The front left-hand or front right-hand side marker lamp is faulty.
X Visit a qualified specialist workshop. b
Check Rear Left Check Rear Left
Sidemarker Lamp Sidemarker Lamp
or
Check Rear Right
Check Rear Right
Sidemarker Lamp Sidemarker Lamp The rear left-hand or rear right-hand side marker lamp is faulty.
X Visit a qualified specialist workshop. b
Check Check
Left
LeftDaytime
Daytime
Running Light
Running Light or
Check Right Day‐
Check Right Day‐
time Running Light time Running Light The left or right-hand daytime running lamp is faulty.
X Visit a qualified specialist workshop. b
Active Headlamps Active Headlamps
Inoperative Inoperative The active light function is defective.
X Visit a qualified specialist workshop. b
Malfunction See Malfunction See
Operator’s Manual Operator’s Manual The exterior lighting is defective.
X Visit a qualified specialist workshop. b
Auto Auto
Lamp
LampFunction
Function
Inoperative
Inoperative The light sensor is defective.
X Visit a qualified specialist workshop. b
Switch Off Lights Switch Off Lights The lights are still switched on when you leave the vehicle. A
warning tone also sounds.
X Turn the light switch to Ã. Display
messages
335On-board computer and displays Z

Display messages
Possible causes/consequences and
M
MSolutions Because there is interference from a strong source of radio waves,
the key is not detected whilst the engine is running.
A warning tone also sounds.
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 220).
X Insert the SmartKey into the ignition lock and bring into key
mode. Â
Remove Remove
'Start'
'Start' But‐
But‐
ton and Insert Key
ton and Insert Key The SmartKey is continually undetected.
The SmartKey detection function has a temporary malfunction or
is faulty. A warning tone also sounds.
X Insert the SmartKey into the ignition lock and turn it to the
desired position.
X Visit a qualified specialist workshop. Warning and indicator lamps in the instrument cluster
Safety
Seat belts Warning/
indicator
lamp
N N
Signal type
Possible causes/consequences and M
MSolutions ü
N
After starting the engine, the red seat belt warning lamp lights up for
6 seconds.
The seat belt warning lamp reminds the driver and front passenger to fasten
their seat belts.
X Fasten your seat belt (Y page 54).ü
N
After starting the engine, the red seat belt warning lamp lights up. In addi-
tion, a warning tone sounds for up to 6 seconds.
The driver's seat belt is not fastened.
X Fasten your seat belt (Y page 54).
The warning tone ceases. Wa
rning and indi cator lamps in the instrument cluster
355On-board computer and displays Z

Warning/
indicator
lamp
N
N Signal type
Possible causes/consequences and M MSolutions ü
N
The red seat belt warning lamp lights up after the engine starts, as soon as
the driver's or the front-passenger door is closed.
The driver or front passenger has not fastened their seat belt.
X Fasten your seat belt (Y page 54).
The warning lamp goes out.
There are objects on the front-passenger seat. X Remove the objects from the front-passenger seat and stow them in a
secure place.
The warning lamp goes out. ü
N
The red seat belt warning lamp flashes and an intermittent audible warning
sounds.
The driver or front passenger has not fastened their seat belt. The vehicle is
being driven faster than 15 mph (25 km/h) or has briefly been driven faster
than 15 mph (25 km/h).
X Fasten your seat belt (Y page 54).
The warning lamp goes out and the intermittent warning tone ceases.
There are objects on the front-passenger seat. The vehicle is being driven
faster than 15 mph (25 km/h) or has briefly been driven faster than 15 mph
(25 km/h).
X Remove the objects from the front-passenger seat and stow them in a
secure place.
The warning lamp goes out and the intermittent warning tone ceases. 356
Warning and indicator lamps in the instrument clusterOn-board computer and displays

Engine
Warning/
indicator
lamp
N N
Signal type
Possible causes/consequences and M
MSolutions ;
N
The yellow Check Engine warning lamp lights up while the engine is running.
There may be a malfunction, for example:
R in the engine management
R in the fuel injection system
R in the exhaust system
R in the ignition system
R in the fuel system
The emission limit values may be exceeded and the engine may be in emer-
gency mode.
X Have the vehicle checked as soon as possible at a qualified specialist work-
shop.
i In 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. 8
N
The yellow reserve fuel warning lamp lights up while the engine is running.
The fuel level has dropped into the reserve range.
X Refuel at the nearest gas station. 8
N
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.
X Check that the fuel filler cap is correctly closed.
X If the fuel filler cap is not correctly closed: close the fuel filler cap.
X If the fuel filler cap is closed: visit a qualified specialist workshop. Warning and indicator lamps in the instrument cluster
363On-board computer and displays Z