Page 160 of 424

157 Exterior lamp switch
Te ch n ica l
data Instruments 
and controlsOperationDrivingInstrument 
cluster displayPractical hints Car care Index Headlamp mode (HEADLAMPS)
(USA only)
The headlamps can be switched on and off manually or 
automatically, or switched to daytime running lamp 
mode.
Manual operation:
The low beam headlamps, parking lamps and license 
plate lamps can be switched on and off with the exterior 
lamp switch. For exterior lamp switch, see above.Automatic operation:
With electronic key in starter switch in position 1 turn 
exterior lamp switch to positionU.
The parking lamps switch on and off automatically 
depending on the brightness of the ambient light.
With the engine running and exterior lamp switch in 
positionU:
The low beam headlamps, parking lamps and license 
plate lamps are switched on and off automatically 
depending on the brightness of the ambient light. 
The low beam headlamps, parking lamps and license 
plate lamps can still be switched on and off manually 
using the exterior lamp switch.
Note:
The headlamps will not be automatically switched on 
under foggy conditions.
Wa r n i n g !
The driver is responsible for the operation of the 
vehicle’s lights at all times. The automatic 
headlamp feature is only an aid to the driver. 
Switch on the vehicle lights by hand when driving 
or traffic conditions require you to do so. 
     
        
        Page 162 of 424
159 Exterior lamp switch
Te ch n ica l
data Instruments 
and controlsOperationDrivingInstrument 
cluster displayPractical hints Car care Index Locator lighting
After unlocking the vehicle with the electronic main key 
during darkness, the fog lamps, parking lamps, 
taillamps and license plate lamps switch on for a 
approx. 40 seconds.
The exterior lamps will be switched off when opening 
the driver’s door.
See “Individual settings” – “LIGHTING” on page 142 for 
instructions on how to activate the function. Headlamp cleaning system
Turn the electronic key in starter switch to position 1 
or 2.
The headlamps will be cleaned with a high-pressure 
water jet when you press the headlamp washer 
button (1).
See page 334 for instructions on filling up the 
windshield/headlamp washer reservoir. 
P54.25-2391-26
1 
     
        
        Page 312 of 424
306 Malfunction and warning messages
Te ch n ica l
data Instruments 
and controlsOperation DrivingInstrument 
cluster displayPractical hints Car care Index
LIGHTING SYSTEM
* C = Category, see page 297Line 1Line 2C*
LOW BEAM,L CHECK LAMP! 2
LOW BEAM,R CHECK LAMP! 2
DISPLAY DEFECTIVE VISIT WORKSHOP!
1
2
TURN SIGNAL, L CHECK LAMP!  2
TURN SIGNAL, R CHECK LAMP!  2
Line 1Line 2C*
L. TURN SIG. RFLECTR CHECK LAMP! 2
R. TURN SIG. RFLECTR CHECK LAMP! 2
TURN SIGNAL F, L CHECK LAMP!  2
TURN SIGNAL F, R CHECK LAMP!  2
BRAKE LIGHT
2
VISIT WORKSHOP! 2
BRAKE LIGHT, L
3
CHECK  LAMP !  2
BRAKE LIGHT, R
3
CHECK  LAMP !  2
3RD BRAKE LIGHT
3
CHECK  LAMP ! 2
HIGH BEAM, L CHECK LAMP! 2
HIGH BEAM, R CHECK LAMP! 2
LICENSE PLATE L, L CHECK LAMP! 2
LICENSE PLATE L, R CHECK LAMP! 2
SWITCH OFF LIGHTS! 1
FRONT FOGLAMP, L CHECK LAMP! 2 
     
        
        Page 313 of 424

307 Malfunction and warning messages
Te ch n ica l
data Instruments 
and controlsOperation DrivingInstrument 
cluster displayPractical hints Car care IndexIn t he ca se of bul b failures in certa in la mps, oth er lamps 
will substitute. See page 354 for instructions on 
replacing bulbs.
* C = Category, see page 297
1 The display or the system is malfunctioning.
2 The brake lamps are switching on after a delay or are permanently 
on – visit workshop immediately.
3 The brake lamps comprise several light emitting diodes. The 
warning message will only appear if all light emitting diodes have 
stopp ed working .
4 Other bulbs will be brought into use as replacements when certain 
lamps blow. FRONT FOGLAMP, R CHECK LAMP! 2
REAR FOGLAMP CHECK LAMP! 2
REVERSE LIGHT, L CHECK LAMP! 2
REVERSE LIGHT, R CHECK LAMP! 2
TAIL LIGHT, L CHECK LAMP! 
SUBSTITUTE LAMP ON!
4
2
TAIL LIGHT, R CHECK LAMP! 
SUBSTITUTE LAMP ON!
4
2
SIDELIGHT, L CHECK LAMP! 
SUBSTITUTE LAMP ON!
4
2
SIDELIGHT, R CHECK LAMP! 
SUBSTITUTE LAMP ON!
4
2 Line 1Line 2C* 
     
        
        Page 408 of 424

402 Index
Te ch n ica l
data Instruments 
and controlsOperation DrivingInstrument 
cluster displayPractical hints Car careIndex
Residual engine heat utilization  ............................ 174
Special settings  ......................................................... 169
Switching on and off  ................................................ 175
Windows fogged on the inside  ................................ 170
Windows fogged on the outside .............................. 171
Automatic transmission  ...............................................229
Emergency operation  ...............................................237
Fluid level ...................................................................332
Program mode selector switch  ...............................236
Selector lever position ..............................................232
BBabySmart
TM airbag deactivation system ..................... 88
Self-test ......................................................................... 89
Backrest ............................................................................. 72
BAS (Brake assist system)  ............................................268
Battery .............................................................................346
Battery recycling  .......................................................348
BATTERY/ALTERNATOR - 
malfunction and warning messages  ......................299
Block heater  ....................................................................249
BRAKE ASSIST - malfunction 
and warning messages  ............................................300
Brake assist system (BAS)  ............................................268Brake fluid  ...........................................240, 292, 393, 395
BRAKE FLUID -
malfunction and warning messages  ......................301
BRAKE LINING WEAR -
malfunction and warning messages  ......................301
Brake pad wear ...............................................................301
Brake warning lamp  ..................................................... 292
Brake fluid low  ......................................................... 292
Brakes  ...................................................238, 240, 268, 272
CCapacities
Fuels, coolants, lubricants etc.  .............................. 393
Card, KEYLESS-GO  ..........................................................28
Cargo tie-down hooks  ................................................... 200
Catalytic converter ........................................................ 220
Center console  .................................................................. 24
Center console lighting  ................................................. 185
Central locking switch  .................................................... 50
Central locking system .................................................... 34
Automatic central locking  .........................................52
Central locking switch  ............................................... 50
Choosing global or selective mode  .....................37, 43
Electronic main key  .................................................... 29