Mercedes-Benz E-Class Coupe 2017 Owner's Manual page 426

Warning/indicator lamp
Possible causes/consequences and
Otherwise:
Leave the vehicle and keep a safe distance from the vehicle until the engine has cooled down.
#
Check the coolant level .
#
Make sure that the air supply to the radiator is not obstructed.
#
Avoiding high loads on the engine, drive on to the nearest qualified specialist workshop. In doing so, ensure that the
#
coolant temperature display remains below 120 °C.
Display messages and warning/indicator lamps 423
M M Solutions