Mercedes-Benz E-Class Quiz
On-board computer and displays

Engine

In this manual: On-board computer and displays
Introduction — 5At a glance — 6Safety — 25Opening and Closing — 17Seats, steering wheel and mirrors — 12Lights and windshield wipers — 11Climate Control — 11Driving and parking — 44On-board computer and displays — 29Stowing and Useful Information. Good to Know — 1Stowing and Useful Information. Storage Options — 10Stowage and convenience features. Convenience features — 7Maintenance and care — 11Roadside assistance — 13Wheels and tires — 13Technical data — 13
~4min read

The engine section of the Mercedes E-Class (4th generation, W212, 2009–2016) covers important warning and malfunction messages that may indicate problems with engine management, cooling or the fuel system. Drivers receive clear instructions on how to act in an emergency and how to avoid engine damage. Additional notes support safe continued driving.

Problem Possible causes/consequences and solutions

The yellow engine diagnostics warning lamp is on while the engine is running.

There may be a malfunction, for example:

  • in engine management
  • in the injection system
  • in the exhaust system
  • in the ignition system (on vehicles with petrol engine)
  • in the fuel system
As a result, emission limits may be exceeded and the engine may run in emergency mode.

Have the vehicle checked at a qualified specialist workshop as soon as possible.

Vehicles with diesel engine: The fuel tank has run completely empty .

After refuelling, start the engine 3 to 4 times in succession.
  • If the yellow engine diagnostics warning lamp goes out, emergency operation is cancelled. The vehicle does not need to be checked.
    		•

    The yellow fuel reserve warning lamp is on while the engine is running.

    The fuel supply has reached the reserve range.

    Auxiliary heater operation is deactivated in the reserve range.

    Refuel at the next filling station.

    The red coolant warning lamp is on while the engine is running and the coolant temperature gauge is at the start of the scale.

    The coolant temperature sensor for the coolant temperature gauge is faulty.

    The coolant temperature is not monitored. If the coolant becomes too hot, the engine may be damaged.

    Stop the vehicle safely as soon as possible and switch off the engine. Do not continue driving!

    Secure the vehicle against rolling away.

    Contact a qualified workshop.

    The red coolant warning lamp is 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 restricted or the electric radiator fan may be faulty.

    The coolant is too hot and the engine is not being cooled sufficiently.

    Observe the additional messages in the multifunction display.

    Stop safely as soon as possible and switch off the engine.

    Secure the vehicle against rolling away.

    Leave the vehicle and do not stay near it until the engine has cooled down.

    Check the coolant level and top up the coolant, observing the warnings .

    If coolant has to be topped up frequently, have the engine cooling system checked.

    Make sure the airflow to the radiator is not blocked, e.g. by frozen slush.

    Only once the coolant temperature has dropped below 120 °C°C, then restart the engine. Otherwise the engine may be damaged.

    Continue driving to the nearest qualified specialist workshop.

    Avoid high engine loads while doing so, e.g. driving uphill and stop-and-go traffic.

    The red coolant warning lamp is on while the engine is running. In addition, a warning tone sounds.

    		 The coolant temperature has exceeded 120 °C. The airflow to the engine radiator may be restricted or the coolant level may be too low.

    WARNING

    The engine is not being cooled sufficiently and may be damaged.

    Do not drive with an overheated engine. Fluids that have leaked or spilled into the engine compartment could ignite.

    Steam from an overheated engine can also cause severe burns, even if only the hood is opened.

    There is a risk of injury!

    Observe the additional messages in the multifunction display.

    Stop safely as soon as possible and switch off the engine.

    Secure the vehicle against rolling away.

    Leave the vehicle and do not stay near it until the engine has cooled down.

    Check the coolant level and top up the coolant, observing the warnings .

    If coolant has to be topped up frequently, have the engine cooling system checked.

    Make sure the airflow to the radiator is not blocked, e.g. by frozen slush.

    At coolant temperatures below 120, drive on only as far as the next qualified workshop.

    Avoid high engine loads while doing so, e.g. driving uphill and stop-and-go traffic.

    The Mercedes E-Class W212 (model years 2009–2016) is equipped with modern warning systems that monitor the engine status. If the yellow engine diagnostics warning lamp lights up, the driver should take the notices seriously and visit a qualified specialist workshop promptly to avoid damage.

    It is particularly important to stop immediately and switch off the engine in the event of overheating or coolant problems. These protective measures prevent major engine damage and ensure your safety on the road.

    With these systems, Mercedes-Benz shows how technology and safety work together in harmony in the E-Class to protect occupants and to preserve engine service life.

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