Mercedes-Benz S-Class Saloon W223 2021 Owner's Manual page 586

584 Display messages and warning/indicator lamps
Warning/indicator lamp
J
Brake system warning lamp
(yellow)
J
Brake system warning lamp
(red)
Possible causes/consequences and
* The yellow brake system warning lamp is lit while the engine is running.
& WARNING Risk of an accident due to 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 qualified specialist workshop.
#
The hill start assist may be malfunctioning.
Adjust your speed and drive on carefully, leaving a suitable distance to the vehicle in front.
#
If the driver's display shows a display message, observe it.
#
Consult a qualified specialist workshop.
#
* The red brake system warning lamp is lit while the engine is running.
Possible causes:
The brake force boosting is malfunctioning and the braking characteristics may be affected.
R
There is insufficient brake fluid in the brake fluid reservoir.
R
Note the messages on the driver's display.
#
Solutions
M
P223 0288 02