Mercedes-Benz S-Class Operator's Manual page 311

Warning and indicator lamps in the instrument cluster
Warning/ N N Signal type
indicator
Possible causes/consequences and M M Solutions
lamp
?
N The red coolant warning lamp lights up while the engine is running and the
coolant temperature gauge is at the start of the bar display.
The temperature sensor for the coolant temperature gauge is defective.
The coolant temperature is no longer being monitored. There is a risk of engine
damage if the coolant temperature is too high.
Pull over and stop the vehicle safely and switch off the engine, paying
X
attention to road and traffic conditions. Do not continue driving under any
circumstances.
Secure the vehicle against rolling away (
X
Consult a qualified specialist workshop.
X
page 190).
Y
309
Z