Engine, On-board computer and displays – Mercedes-Benz 2012 B Class User Manual
Page 233
Engine
Problem
Possible causes/consequences and M Solutions
;
The yellow Check
Engine warning lamp
lights up while the
engine is running.
There may be a malfunction, for example:
R
in the engine management
R
in the fuel injection system
R
in the exhaust system
R
in the ignition system
R
in the fuel system
The emission limit values may be exceeded and the engine may
be running in emergency mode.
X
Have the vehicle checked as soon as possible at a qualified
specialist workshop.
i
In some states, you must immediately visit a qualified
specialist workshop as soon as the yellow Check Engine warning
lamp lights up. This depends on the locally applicable legal
requirements. If in doubt, check whether such legal regulations
apply in the state in which you are currently driving.
æ
The yellow reserve fuel
warning lamp lights up
while the engine is
running.
The fuel level has dropped into the reserve range.
X
Refuel at the nearest gas station.
æ
The yellow reserve fuel
warning lamp flashes
while the engine is
running.
The fuel system pressure is too low. The fuel filler cap is not closed
correctly or the fuel system is leaking.
X
Check that the fuel filler cap is correctly closed.
X
If the fuel filler cap is not correctly closed: close the fuel filler
cap.
X
If the fuel filler cap is closed: visit a qualified specialist
workshop.
?
The red coolant
warning lamp lights up
while the engine is
running and the coolant
temperature gage is at
the start of the scale.
The temperature sensor for the coolant temperature gage is
defective.
The coolant temperature is no longer being monitored. There is a
risk of engine damage if the coolant temperature is too high.
X
Pull over and stop the vehicle safely and switch off the engine,
paying attention to road and traffic conditions. Do not continue
driving under any circumstances.
X
Secure the vehicle against rolling away (
Y
page 149).
X
Consult a qualified specialist workshop.
Warning and indicator lamps in the instrument cluster
231
On-board computer and displays
Z