The tank content is measured with two lever sensors which are separately linked to the instrument cluster. Each lever sensor is connected with a separate ground (analog ground) and a sensor line (analog positive) to the instrument cluster. The different methods of determining the fuel level for each tank half is adapted by means of the coding data. The gauge shows a percentage of the total contents of both tank halves.
There is no reserve contact in the level sending unit to activate the fuel reserve warning lamp. The fuel reserve warning lamp is switched on dependent on the tank contents in comparison with a reserve threshold value. The fuel tank content is made available in the form of a telegram on the CAN bus to serve as information for engine control. The fuel reserve warning lamp switches on as a function check when terminal 15 (pre-drive check) is switched on.
If the instrument cluster detects a fault in the power circuit of one or both lever-type sensors, control of the fuel gauge is continued with the aid of the consumption signal. After stopping the vehicle and then switching on the ignition again, the fuel gauge is set to empty and the fuel reserve warning lamp switched on if a fault is still detected in the power circuit of one or both lever-type sensors.