
Display messages
Possible causes/consequences and
0050
0050Solutions 0075
Rear Left Malfunc‐ Rear Left Malfunc‐
tion Service tion Service
Required Required
orRear
Rear
Right Malfunction
Right Malfunction
Service Required Service Required The rear left-hand or right-hand restraint system is malfunctioning.
The 0075 warning lamp also lights up in the instrument cluster.
G WARNING
The air bags or Emergency Tensioning Devices may either be triggered 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 immediately. 0075
Rear Rear
Center
Center Malfunc‐
Malfunc‐
tion Service
tion Service
Required Required The rear center restraint system is malfunctioning. The
0075warning
lamp also lights up in the instrument cluster.
G WARNING
The air bags or Emergency Tensioning Devices may either be triggered 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 immediately. 0075
Left Side Curtain Left Side Curtain
Airbag Malfunction Airbag Malfunction
Service Required Service Required
or
Right Side Curtain
Right Side Curtain
Airbag Malfunction Airbag Malfunction
Service Required Service Required The left-hand or right-hand window curtain air bag is malfunctioning.
The 0075 warning lamp also lights up in the instrument cluster.
G WARNING
The left or right window curtain air bag may either be triggered unin-
tentionally or, in the event of an accident, may not be triggered.
There is an increased risk of injury.
X Visit a qualified specialist workshop immediately. 232
Display
messagesOn-board computer and displays

Display messages
Possible causes/consequences and
0050
0050Solutions X
Visit a qualified specialist workshop immediately.
For further information about the Occupant Classification System, see (Y page 50). Lights
i Vehicles with LED bulbs in the light clusters:
The display message for the corresponding lamp only appears when all of the LEDs in the lamp
have failed. Display messages
Possible causes/consequences and
0050
0050Solutions 0049
Example: Check Left
Check Left
Low Beam
Low Beam The corresponding bulb is faulty.
X Visit a qualified specialist workshop.
or X Check whether you are permitted to replace the bulb yourself
(Y page 111). 0049
Active Headlamps Active Headlamps
Inoperative Inoperative The active light function is faulty.
X Visit a qualified specialist workshop. 0049
Intell. Light Sys‐ Intell. Light Sys‐
tem Inoperative tem Inoperative The Intelligent Light System is faulty. The lights remain available with-
out the Intelligent Light System.
X Visit a qualified specialist workshop. 0049
Malfunction See Malfunction See
Operator's Manual Operator's Manual The exterior lighting is malfunctioning.
X Visit a qualified specialist workshop. Vehicles with trailer tow hitch: a fuse may have blown.
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 144).
X Check the fuses (Y page 324).
X If necessary, replace the blown fuse. Observe the warning notes.
If the multifunction display still shows the display message:
X Visit a qualified specialist workshop. 0049
Malfunction See Malfunction See
Operator's Manual Operator's Manual The exterior lighting is malfunctioning.
X Visit a qualified specialist workshop. 0049
Auto Auto
Headlamps
Headlamps Inop‐
Inop‐
erative
erative The light sensor is defective.
X Visit a qualified specialist workshop. Display
messages
235On-board computer and displays Z

Display messages
Possible causes/consequences and
0050
0050Solutions 0049
Switch Off Lights Switch Off Lights You leave the vehicle and the lights are switched on. A warning tone
also sounds.
X Turn the light switch to the 0058position. 0049
Switch On Headlamps Switch On Headlamps You are driving with low-beam headlamps switched off.
X Turn the light switch to the 0058or0058 position. Adaptive Highbeam
Adaptive Highbeam
Assist Currently Assist Currently
Unavailable See Unavailable See
Operator's Manual Operator's Manual Adaptive Highbeam Assist is deactivated and temporarily inoperative.
Possible causes are:
R the windshield in the camera's field of vision is dirty
R visibility is impaired due to heavy rain, snow or fog
X Clean the windshield.
If the system detects that the camera is fully operational, the Adap‐
Adap‐
tive Highbeam Assist Now Available
tive Highbeam Assist Now Available message is displayed.
Adaptive Highbeam Assist is operational again. Adaptive Highbeam
Adaptive Highbeam
Assist Inoperative
Assist Inoperative Adaptive Highbeam Assist is faulty.
X
Visit a qualified specialist workshop. Engine
Display messages
Possible causes/consequences and
0050 0050Solutions 00BD
Check Check
Coolant
Coolant Level Level
See Operator's Man‐
See Operator's Man‐
ual ual The coolant level is too low.
! Avoid longer journeys when there is insufficient coolant in the
engine cooling system. You could otherwise damage the engine.
X Add coolant, observing the warning notes before doing so
(Y page 299).
If you have to add coolant frequently:
X Contact a qualified specialist workshop and have the engine cooling
system checked. 00AC The fan motor is defective.
X At coolant temperatures below 248 ‡(120 †), drive to the nearest
qualified specialist workshop.
X Avoid heavy loads on the engine as you do so, e.g. driving in moun-
tainous terrain and stop-and-go traffic. 236
Display messagesOn-board computer and displays

Display messages
Possible causes/consequences and
0050
0050Solutions Because there is interference from a strong source of radio waves, the
SmartKey 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 144).
X Insert the SmartKey into the ignition lock and drive in SmartKey
mode. 00AF
Remove 'Start' But‐ Remove 'Start' But‐
ton and Insert Key ton and Insert Key R
The SmartKey detection function has a temporary malfunction or is
faulty.
R The SmartKey is continually undetected.
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
General notes
Some systems carry out a self-diagnosis when the ignition is switched on. Therefore, some indicator and warning lamps may light up or flash temporarily. This behavior is non-critical. These indicator
and warning lamps only indicate a malfunction if they light up or flash after starting the engine or
whilst driving. Safety
Seat belts Warning/
indicator
lamp
0051 0051
Signal type
Possible causes/consequences and 0050 0050Solutions 00E9
0051
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 46).00E9
0051
After starting the engine, the red seat belt warning lamp lights up. In addition, a
warning tone sounds for up to 6 seconds.
The driver's seat belt is not fastened.
X Fasten your seat belt (Y page 46).
The warning tone ceases. Wa
rning and indi cator lamps in the instrument cluster
251On-board computer and displays Z

Warning/
indicator
lamp
0051
0051 Signal type
Possible causes/consequences and 0050 0050Solutions 00E9
0051
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 46).
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. 00E9
0051
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 46).
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. 252
Warning and indicator lamps in the instrument clusterOn-board computer and displays

Warning/
indicator
lamp
0051 0051
Signal type
Possible causes/consequences and 0050
0050Solutions 00490024
0051
0049 (USA only), 0024(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.
X Observe the additional display messages in the multifunction display. 0075
0051
The red restraint system warning lamp is lit while the engine is running.
The restraint system is malfunctioning.
G WARNING
The air bags or Emergency Tensioning Devices may either be triggered uninten-
tionally or, in the event of an accident, may not be triggered.
There is an increased risk of injury.
X Observe the additional display messages in the multifunction display.
X Drive on carefully.
X Contact a qualified specialist workshop and have the restraint system checked.
For further information about the restraint system, see (Y page 42).Engine
Warning/
indicator
lamp
0051 0051
Signal type
Possible causes/consequences and 0050
0050Solutions 00B9
0051
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 (for vehicles with gasoline engines)
R in the fuel system
The emission limit values may be exceeded and the engine may be in emergency mode.
X Visit a qualified specialist workshop immediately.
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 require-
ments in effect in these states. If in doubt, check whether such legal regulations
apply in the state in which you are currently driving. 00B6
0051
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. Warning and indicator lamps in the instrument cluster
259On-board computer and displays Z

Warning/
indicator
lamp
0051
0051 Signal type
Possible causes/consequences and 0050 0050Solutions 00B6
0051
The yellow reserve fuel warning lamp flashes while the vehicle is in motion.
In addition, the 00B9Check Engine warning lamp may light up.
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.00AC
0051
The red coolant warning lamp lights up while the engine is running and the
coolant temperature gage is at the start of the scale.
The temperature sensor for the coolant temperature gage is malfunctioning.
The coolant temperature is no longer being monitored. There is a risk of engine
damage if the coolant temperature is too high.
X Pull 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.
X Secure the vehicle against rolling away (Y page 144).
X Consult a qualified specialist workshop. 260
Warning and indicator lamps in the instrument clusterOn-board computer and displays

Warning/
indicator
lamp
0051
0051 Signal type
Possible causes/consequences and 0050 0050Solutions X
At coolant temperatures below 248 ‡ (120 †), drive to the nearest qualified
specialist workshop.
X Avoid heavy loads on the engine as you do so, e.g. driving in mountainous terrain
and stop-and-go traffic. Driving systems
Warning/
indicator
lamp
0051
0051 Signal type
Possible causes/consequences and 0050 0050Solutions 00BA
0051
The red distance warning lamp lights up while the vehicle is in motion. A warning
tone also sounds.
You are approaching a vehicle, a pedestrian or a stationary obstacle in your line of travel at too high a speed.
X Be prepared to brake immediately.
X Pay careful attention to the traffic situation. You may have to brake or take
evasive action.
Further information about Active Distance Assist DISTRONIC (Y page 157).
Further information on the distance warning function of Active Brake Assist
(Y page 65).
Further information on the distance warning function of Active Brake Assist with
cross-traffic function (Y page 70).262
Warning and indicator lamps in the instrument clusterOn-board computer and displays