1. Electronic speedometer. The electronic speedometer drive, as opposed to the traditional mechanical drive with a cable, allows for greater accuracy of readings. This primarily concerns the lower speed range: conventional speedometers only start working at 20 km/h. The device installed on the E-class models shows the speed starting from 1 km/h and thus makes it easier to read the readings, for example, in places with a significant speed limit. The speedometer receives data from the ABS control unit. In turn, it processes information from the sensor on the left front wheel. Information about the distance traveled is displayed on the liquid crystal display. The data is stored in the ROM memory of the instrument cluster when the ignition is off or the terminal is removed from the battery. If, without the key in the ignition, you press the button on the lower left side next to the speedometer, the distance traveled, temperature and time will appear on the liquid crystal displays for about 30 seconds.
2. Fuel level indicator. Fuel level information received from both parts of the fuel tank (by the resistance value of the lever sensor) is displayed in the instrument cluster. In case of malfunctions, the fuel gauge shows "tank empty", the fuel reserve indicator light does not light.
3. Tachometer. The signal is taken from the engine flywheel by a sensor and converted in the Motronic system controller from sinusoidal to linear.
4. Instrument lighting. The so-called light pressure technique is used; when the lighting is turned off, the maximum brightness of the instrument lighting is achieved.
5. Control and signal lamps. They are located on the side in the corners of the instrument cluster. Regardless of the modification, lamps are installed that can be replaced if necessary.
6. Oil pressure gauge. This previously familiar indicator is missing. Oil pressure is controlled indirectly by the oil level.
The electronic board of the instrument cluster can only be replaced completely, with the exception of the ambient air temperature gauge (SA). The board is held in place by clips. The symbols of the indicator lamps have different designs depending on the vehicle model.
(Article was borrowed from the website: MercedesMan.ru)