2020 MERCEDES-BENZ GLS SUV Owners Manual

Wa
rning/indicator lamp
Possible causes/consequences and M
MSolutions
ï Tr ailer tow hit chwarning
lamp *T
hered trailer hitch warning lamp is lit.
The trailer hitch is not operational or is swivelling. &
WARNING Risk of an accident if the ball neck is not loc ked
The trailer may become de tach ed. #
Stop theve hicle immediately in accordance with the traf fic conditions. Do not continue driving. #
Uncouple the trailer and secure it against rolling away. #
Initiate a new swivel mo vement and do not re-couple the trailer until thewa rning/indicator lamp goes out. #
Notethe messages on the multifunction displa y.
If th e trailer hitch is swivelling: #
Wait until the ball neck has reached the operational position. 494
Display messages and warning/indicator lamps

Engine
Wa
rning/indicator lamp
Possible causes/consequences and M
MSolutions
ÿ Coolant warning lamp (red) *T
he red coolant warning lamp is lit while the engine is running.
Po ssible causes:
R The temp erature sensor is malfunctioning
R The coolant le vel is too low
R The air supply tothera diator is obstructed
R The radiator fan is faulty
R The engine coolant pump is faulty
If th ere is an additional warning tone, the coolant temp erature has exceeded 120°C. &
WARNING Danger of bu rns when opening the bonn et
If yo u open the engine bonn etwhen the engine has overheated or during a fire inthe engine compartment, you
could come into contact wi thhot gases or other escaping operating fluids. #
Before opening the bonn et, allow the engine tocool down. #
Intheeve nt of a fire inthe engine compartment, keep the engine bonn etclosed and call thefire service. #
Stop theve hicle immediately in accordance with the traf fic conditions and switch off the engine. Do not continue
driving. #
Notethe messages on the multifunction displa y. Displ
aymessa ges and warning/indicator lamps 495

Wa
rning/indicator lamp
Possible causes/consequences and M
MSolutions
If th e coolant temp erature display is at the lo wer end of thete mp erature scale: #
Consult a qualified specialist workshop.
If th e coolant temp erature display is at the upper end of thete mp erature scale: #
Exit theve hicle and keep a safe dis tance from it until the engine has cooled down. #
Check the coolant le vel (/ page 362). #
Make sure that the air supply tothera diator is not obstructed. #
Avoiding high loads on the engine, drive tothe nearest qualified specialist workshop. In doing so, ensure that the
coolant temp erature display remains below 120°C.
ÿ Coolant warning lamp (yel‐
low) *T
he yellow coolant warning lamp is lit while the engine is running.
Po ssible causes:
R The temp erature sensor is malfunctioning
R The charge air, transmission oil or bat tery cooling is faulty #
Avoiding high loads on the engine, drive tothe nearest qualified specialist workshop.
;
Engine diagnosis warning
lamp *T
he yellow engine diagno stics warning lamp is lit while the engine is running.
A malfunction has occu rred in the engine, theex haust sy stem or the fuel sy stem.
The emissions limit value may ha vebeen exceeded and the engine may be running in emergency operation mode. #
Have theve hicle checked as soon as possible at a qualified specialist workshop.
Ve hicles with a diesel engine: the fuel tank may ha vebeen run dr y. 496
Display messages and warning/indicator lamps

Wa
rning/indicator lamp
Possible causes/consequences and M
MSolutions #
Start the engine thre eto four times af terre fuelling.
If th eye llow engine diagnosis warning lamp goes out, emer gency operation mode is cancelled. The vehicle need
not be checked.
#
Elect rical fault warning
lamp *T
hered elect rical fault warning lamp is lit.
There is a fault in the electrics. #
Notethe messages on the multifunction displa y.
8
Fu elreser vewarning lamp
lights up *T
he yellow fuel reser ve wa rning lamp lights up while the engine is running.
The fuel supp lyhas dropped into there ser verange. #
Refuel. Displ
aymessa ges and warning/indicator lamps 497

Brakes
Wa
rning/indicator lamp
Possible causes/consequences and M
MSolutions
! Elect ric pa rking brake indi‐
cator lamp (red)
!
The elect ric pa rking brake
(yellow) indicator lamp *T
he red elect ric pa rking brake indicator lamp flashes or is lit.
The yellow elect ric pa rking brake indicator lamp also lights up in theev ent of a malfunction. #
Notethe messages on the multifunction displa y.
J
Brake sy stem warning lamp
(yellow) *T
he yellow brake sy stem warning lamp is lit while the engine is running. &
WARNING Risk of an accident due toa brake sy stem malfunction
If th e brake sy stem is malfunctioning, braking characteristics may be impaired. #
Drive on carefull y. #
Have the brake sy stem checked immediately at a qualified specialist workshop. #
Adjust your speed and drive on carefull y,leaving a suitable dis tance totheve hicle in front. #
Ifth e multifunction display sho wsa display message, obse rve it. 498
Display messages and warning/indicator lamps

Wa
rning/indicator lamp
Possible causes/consequences and M
MSolutions #
Consult a qualified specialist workshop.
J Brake sy stem warning lamp
(red) *T
he red brake sy stem warning lamp is lit while the engine is running.
Po ssible causes:
R The brake forc e boosting is malfunctioning and the braking characteristics may be af fected.
R The reis insuf ficient brake fluid in the brake fluid reser voir. #
Notethe messages on the multifunction displa y. &
WARNING Risk of accident and inju ryif brake forc e boosting is malfunctioning
If brake forc e boosting is malfunctioning, increased brake pedal forc e may be necessary for braking. The braking
ch aracteristics may be impaired. The braking dis tance can increase in emergency braking situations. #
Stop in a safe location immediately. Do not continue driving! #
Consult a qualified specialist workshop. &
WARNING Risk of an accident due tolow brake fluid le vel
If th e brake fluid le vel is too lo w,the braking ef fect and the braking characteristics may be impaired. #
Stop theve hicle as soon as possible, paying attention toroad and traf fic conditions. Do not continue driv‐
ing. #
Consult a qualified specialist workshop. Display messages and
warning/indicator lamps 499

Wa
rning/indicator lamp
Possible causes/consequences and M
MSolutions #
Do not top up the brake fluid. Driving sy
stems Wa
rning/indicator lamp
Possible causes/consequences and M
MSolutions
æ Ac tive Brake Assi stwa rning
lamp *T
he white Active Brake Assi stwa rning lamp is lit.
The sy stem is switched off or una vailable.
L Wa rning lamp for dis tance
wa rning function *T
he red dis tance warning lamp lights up while theve hicle is in motion.
The dis tance totheve hicle in front is too small forth e speed selected.
If th ere is an additional warning tone, you are approaching an obs tacle at too high a speed. #
Be prepared tobrake immediatel y. #
Increase the dis tance.
Fu nction of Active Brake Assi st (/ page 248). 500
Displaymessa ges and warning/indicator lamps

Wa
rning/indicator lamp
Possible causes/consequences and M
MSolutions
ä Suspension warning lamp
(yellow) *T
he yellow AIRMATIC / E- ACTIVE BODY CONTROL warning lamp is lit.
A fault has occur red in AIRMATIC / E- ACTIVE BODY CONT ROL. #
Notethe messages on the multifunction displa y.
ä
Suspension warning lamp
(red) *T
he red AIRMATIC / E- ACTIVE BODY CONTROL warning lamp is lit.
A fault has occur red in AIRMATIC / E- ACTIVE BODY CONTROL.
* NO
TEThe vehicle's driving characteristics will ha vechanged significantl y. #
Consult a qualified specialist workshop. #
Notethe messages on the multifunction displa y. #
Consult a qualified specialist workshop. Display messages and
warning/indicator lamps 501