Problems with the engine

Problem Possible causes/consequences and Solutions
The engine does not start. The starter motor can be heard. - There is a malfunction in the engine electronics.
- There is a malfunction in the fuel supply.

- Try to start the engine again. Avoid excessively long and frequent attempts to start the engine as these will drain the battery.

If the engine does not start after several attempts:
- Consult a qualified specialist workshop, e.g. an authorized Mercedes-Benz Center.
The engine does not start. You cannot hear the starter motor. The on-board voltage is too low because the battery is too weak or discharged.
- Jump-start the vehicle.
If the engine does not start despite attempts to jump-start it:
- Consult a qualified specialist workshop, e.g. an authorized Mercedes-Benz Center.
The starter motor was exposed to a thermal load that was too high.
- Allow the starter motor to cool down for approximately two minutes.
- Try to start the engine again.
If the engine still does not start:
- Consult a qualified specialist workshop, e.g. an authorized Mercedes-Benz Center.
The engine is not running smoothly and is misfiring. There is a malfunction in the engine electronics or a mechanical component of the engine management system.
- Only depress the accelerator pedal slightly.
- Have the cause rectified immediately at a qualified specialist workshop, e.g. an authorized Mercedes-Benz Center.
Otherwise, non-combusted fuel may get into the catalytic converter and damage it.
The coolant temperature gauge shows a value above 248 °F (120 °C). The coolant level is too low. The coolant is too hot and the engine is no longer being cooled sufficiently.
- Stop as soon as possible and allow the engine and the coolant to cool down.
- Check the coolant level. Observe the warning notes as you do so and add coolant if necessary.
    See also:

    Unlocking the driver's door(mechanical key)
    If the vehicle can no longer be unlocked with the SmartKey, use the mechanical key. If you use the mechanical key to unlock and open the driver's door, the anti-theft alarm system will be trigge ...

    Important safety notes
    A license agreement must exist in order to activate the mbrace service. Ensure that your system is activated and ready for use, and press the MB Info call button to register. If any of the st ...

    Cleaning the exterior lighting
    Clean the plastic lenses of the exterior lights with a wet sponge and a mild cleaning agent, e.g. Mercedes-Benz car shampoo or cleaning cloths. Only use cleaning agents or cleaning cloths w ...