Seat belt

Problem Possible causes/consequences and Solutions
starting the

After starting the engine, the red seat belt warning lamp lights up for six seconds.

The seat belt warning lamp reminds the driver and front passenger to fasten their seat belts.
Fasten your seat belt
starting the

After starting the engine, the red seat belt warning lamp lights up. In addition, a warning tone sounds for up to six seconds.

The driver's seat belt is not fastened. Risk of injury

The driver's seat belt is not fastened.
The warning tone ceases. Fasten your seat belt.
The warning tone ceases.

The red seat belt

The red seat belt warning lamp lights up after the engine starts, as soon as the driver's or the front-passenger door is closed.

The driver or front passenger has not fastened their seat belt. Risk of injury

The driver or front passenger has not fastened their seat belt.
The warning lamp goes out. Fasten your seat belt.
The warning lamp goes out.

There are objects on the front-passenger seat. Risk of injury

There are objects on the front-passenger seat.
front-passenger seat and stow Remove the objects from the front-passenger seat and stow them in a secure place.
The warning lamp goes out.

The red seat belt

The red seat belt warning lamp flashes and an intermittent audible warning sounds.

The driver or front passenger has not fastened their seat belt. In Risk of injury

The driver or front passenger has not fastened their seat belt. In addition, you are driving faster than 15 mph (25 km/h) or you have briefly driven faster than 15 mph (25 km/h).
The warning lamp goes out and the intermittent warning tone Fasten your seat belt.
The warning lamp goes out and the intermittent warning tone ceases.

There are objects on the front-passenger seat. In addition, you are Risk of injury

There are objects on the front-passenger seat. In addition, you are driving faster than 15 mph (25 km/h) or you have briefly driven faster than 15 mph (25 km/h).
front-passenger seat and stow Remove the objects from the front-passenger seat and stow them in a secure place.
The warning lamp goes out and the intermittent warning tone ceases.

    See also:

    DEF refill bottle
    DEF refill bottles can be obtained at many gas stations or at an authorized Mercedes-Benz Center. Refill bottles without a threaded cap do not provide overfill protection. DEF may leak if over ...

    Connecting an external device
    Do not leave external devices in the vehicle as extreme temperatures (e.g. direct sunlight or extremely low outside temperatures) could cause them to malfunction (see the operating instructions ...

    SmartKey
    0 To remove the SmartKey (shift the transmission to position P) 1 Power supply for some consumers, such as the windshield wipers 2 Ignition (power supply for all consumers) and drive position 3 T ...