Engine
| Problem | Possible causes/consequences and
Solutions |
![]() The yellow Check Engine warning lamp lights up while the engine is running. |
There may be a malfunction, for example: • in the engine management • in the fuel injection system • in the exhaust system • in the ignition system (for vehicles with a gasoline engine) • in the fuel system The emission limit values may be exceeded and the engine may be running in emergency mode. Have the vehicle checked as soon as possible at a qualified specialist
workshop.
|
Vehicles with a diesel engine: the fuel tank has been run dry. Start the engine three to four times after refueling.If the yellow Check Engine warning lamp goes out, emergency running mode is canceled. The vehicle need not be checked. |
|
| The yellow reserve fuel warning lamp flashes while the
vehicle is in motion. In addition, the yellow
Check Engine warning lamp may light up. |
The fuel system pressure is too low. The fuel filler cap is not
closed correctly or the fuel system is leaking. Observe the additional display messages in the multifunction
display. Check that the fuel filler cap is correctly closed. If the fuel filler cap is not correctly closed: close the fuel
filler cap. If the fuel filler cap is closed: visit a qualified specialist
workshop. |
| The yellow reserve fuel warning lamp lights up while the engine is running. | The fuel level has dropped into the reserve range. Refuel at the nearest gas station. |
See also:
Switching the ZONE function on/off
•► To switch on: press the
button.
The indicator lamp above the button
lights up.
Dual-zone automatic climate control: the
temperature setting for the driver's side is
not adopt ...
Important safety notes
WARNING
When expanding the cargo volume, always
fold the seat backrests fully forward.
Unless you are transporting cargo, the seat
backrests must remain properly locked in the
upright positi ...
PRE-SAFE® Brake
PRE-SAFE® Brake is only available in vehicles
with DISTRONIC PLUS.
Observe the "Important safety notes"
section
PRE-SAFE® Brake can help you to minimize
the risk of a frontal collisi ...

Solutions
In some states, you are required by law to immediately
visit a qualified specialist workshop as soon as the yellow Check Engine
warning lamp lights up. If in doubt, check whether such legal
regulations apply in the state/province in which you are currently
driving.