Page 280 of 390
Warning/
indicator
lampNSignal type
Possible causes/consequences and M
Solutions
?NThe red coolant warning lamp comes on while the engine is running.
The coolant level is too low.
If the coolant level is correct, the airflow to the engine radiator may be blocked or
the electric engine radiator fan may be defective.
The coolant is too hot and the engine is no longer being cooled sufficiently.
XObserve the additional display messages in the multifunction display.
XPull over and stop the vehicle safely and switch off the engine, paying attention
to road and traffic conditions.
XSecure the vehicle against rolling away (Ypage 153).
XLeave the vehicle and keep a safe distance from the vehicle until the engine has cooled down.
XCheck the coolant level and add coolant, observing the warning notes
(Ypage 317).
XIf you have to add coolant frequently, have the engine cooling system checked.
XMake sure that the air supply to the engine radiator is not blocked, e.g. by snow,
slush or ice.
XDo not start the engine again until the coolant temperature is below 248 ‡
(120 †). Otherwise, the engine could be damaged.
XDrive to the nearest qualified specialist workshop.
XAvoid heavy loads on the engine as you do so, e.g. driving in mountainous terrain
and stop-and-go traffic.
?N The red coolant warning lamp comes on while the engine is running.
The coolant temperature has exceeded 248 ‡ (120 †). The airflow to the engine
radiator may be blocked or the coolant level may be too low.
GWARNING
The engine is not being cooled sufficiently and may be damaged.
Do not drive when your engine is overheated. This can cause some fluids which
may have leaked into the engine compartment to catch fire.
Steam from the overheated engine can also cause serious burns which can occur
just by opening the hood.
There is a risk of injury.
XObserve the additional display messages in the multifunction display.
XPull over and stop the vehicle safely and switch off the engine, paying attention
to road and traffic conditions.
XSecure the vehicle against rolling away (Ypage 153).
XLeave the vehicle and keep a safe distance from the vehicle until the engine has
cooled down.
XCheck the coolant level and add coolant, observing the warning notes
(Ypage 317).
XIf you have to add coolant frequently, have the engine cooling system checked.
XMake sure that the air supply to the engine radiator is not blocked, e.g. by snow,
slush or ice.
278Warning and indicator lamps in the instrument cluster
On-board computer and displays
Page 281 of 390
Warning/
indicator
lampNSignal type
Possible causes/consequences and M
Solutions
XAt coolant temperatures below 248 ‡ (120 †), drive to the nearest qualified
specialist workshop.
XAvoid heavy loads on the engine as you do so, e.g. driving in mountainous terrain
and stop-and-go traffic.
Driving systems
Warning/
indicator
lampNSignal type
Possible causes/consequences and M
Solutions
·NThe red distance warning lamp lights up while the vehicle is in motion. A warning
tone also sounds.
You are approaching a vehicle, a pedestrian or a stationary obstacle in your line of travel at too high a speed.
XBe prepared to brake immediately.
XPay careful attention to the traffic situation. You may have to brake or take
evasive action.
Further information on Distance Pilot DISTRONIC (
Ypage 168).
Further information on the distance warning function of Active Brake Assist
(
Ypage 64).
Warning and indicator lamps in the instrument cluster279
On-board computer and displays
Z
Page 282 of 390
Tires
Warning/
indicator
lampNSignal type
Possible causes/consequences and M
Solutions
hNThe yellow tire pressure monitor warning lamp (pressure loss/malfunction) is lit.
The tire pressure monitor has detected a loss of pressure in at least one of the tires.
GWARNING
Tire pressures that are too low pose the following hazards:
Rthey may burst, especially as the load and vehicle speed increase.
Rthey may wear excessively and/or unevenly, which may greatly impair tire trac-
tion.
Rthe driving characteristics, as well as steering and braking, may be greatly
impaired.
There is a risk of an accident.
XStop the vehicle without making any sudden steering or braking maneuvers. Pay
attention to the traffic conditions as you do so.
XSecure the vehicle against rolling away (Ypage 153).
XObserve the additional display messages in the multifunction display.
XCheck the tires and, if necessary, follow the instructions for a flat tire
(Ypage 326).
XCheck the tire pressure (Ypage 348).
XIf necessary, correct the tire pressure.
hN The yellow tire pressure monitor warning lamp (pressure loss/malfunction)
flashes for approximately one minute and then remains lit.
The tire pressure monitor is faulty.
GWARNING
The system is possibly unable to recognize or register low tire pressure.
There is a risk of an accident.
XObserve the additional display messages in the multifunction display.
XVisit a qualified specialist workshop immediately.
280Warning and indicator lamps in the instrument cluster
On-board computer and displays
