2022 MERCEDES-BENZ GLS SUV Owners Manual

Warning/indicator lamp Possible causes/consequences and
P Solutions

Warning/indicator lamp Possible causes/consequences and
P Solutions
ï
T railer tow hitch warning
lamp * The red trailer hitch warning lamp is lit.
The trailer hitch is not operational or is swivelling. &
WARNING Risk of an accident if t
he ball neck is not locked
The trailer may become detached. 
Stop the vehicle immediately in accordance with the tr
aPc conditions. Do not continue driving. 
Uncouple the trailer and secure it against rolling away. 
Initiate a new swivelling procedure and do not re-couple the trailer until the display message disappears. 
Note the messages on the instrument display.
If the trailer hitch is swivelling: 
Wait until the ball neck has reached the operational position. Display messages and warning/indicator lamps
511

Engine
Warning/indicator lamp Possible causes/consequences and
P Solutions

Warning/indicator lamp Possible causes/consequences and
P Solutions
Note the messages on the instrument display.
If the coolant temperature display is at the lower end of the temperature scale: 
Consult a qualiNed specialist workshop.
If the coolant temperature display is at the upper end of the temperature scale: 
Exit the vehicle and keep a safe distance from it until the engine has cooled down. 
Check the coolant level (  pag
e 371). 
Make sure that the air supply to the radiator is not obstructed. 
Avoiding high loads on the engine, drive to the nearest q
ualiNed specialist workshop. In doing so, ensure that the
coolant temperature display remains below 120°C.

Warning/indicator lamp Possible causes/consequences and
P Solutions

Warning/indicator lamp Possible causes/consequences and
P Solutions

Warning/indicator lamp Possible causes/consequences and
P Solutions
M
Br ake system warning lamp
(yellow) * The yellow brake warning lamp is lit while the vehicle is running. &
WARNING Risk of an accident due t o a brake system malfunction
If the brake system is malfunctioning, braking characteristics may be impaired. 
Drive on carefully. 
Have the brake system checked immediately at a q
ualiNed specialist workshop. 
Adjust your speed and drive on carefully, leaving a suitable distance to the vehicle in front. 
If the instrument display shows a display message, observe it. 
Consult a q
ualiNed specialist workshop.
M
Br
ake system warning lamp
(red) * The red brake warning lamp is lit while the vehicle is running.
Possible causes:
= The br
ake force boosting is malfunctioning and the braking characteristics may be aMected.
= There is insuPcient brake Ouid in the brake Ouid reservoir. 
Note the messages on the instrument display. &
WARNING Risk of accident and injur
y if brake force boosting is malfunctioning
If brake force boosting is malfunctioning, increased brake pedal force may be necessary for braking. The braking
c
haracteristics may be impaired. The braking distance can increase in emergency braking situations. 516
Display messages and warning/indicator lamps

Warning/indicator lamp Possible causes/consequences and
P Solutions
Stop in a safe location immediately. Do not continue driving! 
Consult a qualiNed specialist workshop. &
WARNING Risk of an accident due t
o low brake Ouid level
If the brake Ouid le
vel is too low, the braking eMect and the braking characteristics may be impaired. 
Stop the vehicle as soon as possible, paying attention to road and tr
aPc conditions. Do not continue driving. 
Consult a q
ualiNed specialist workshop. 
Do not top up the brake Ouid.Driving systems
Warning/indicator lamp Possible causes/consequences and
P Solutions
/
W
arning lamp for distance
warning function * The red distance warning lamp lights up while the vehicle is in motion.
The distance to the vehicle in front is too small for the speed selected.
If t here is an additional warning tone, you are approaching an obstacle at too high a speed. 
Be prepared to brake immediately. 
Increase the distance.
Function of Active Brake Assist (  pag
e 255). Display messages and warning/indicator lamps
517