The tank content is measured with two lever-type sending units which are separately connected to the instrument cluster electronics (IKE ). Each lever-type sensor is connected with its own ground (analog ground) and sensor line (analog positive) to the instrument cluster electronics (IKE ). There is no reserve contact in the level sensor unit to activate the fuel reserve warning lamp. The fuel reserve warning lamp is switched as a function of the tank contents by comparison with a reserve threshold value.
At present tank sizes with 85l and 95l capacity are installed in the 7 Series (E38). A 95l tank can be recognized by the fact that it extends lower than the floor assembly and a stone guard is installed. At present, only a 70l tank is installed in the 5 Series (E39). The different methods of determining the fuel level for the fuel gauge for the 85 litre / 95 litre (E38), 70 litre (E39) and 95 litre (E53) fuel tank are adopted as a function of the coding data.
If defined draining of the left-hand or right-hand tank half is necessary for test purposes, particular care must be taken to ensure that the correct connection is used (on 7 Series E38 only). It is located on the left-hand half of the tank for both tank halves. On both drain connections, a landscape rectangle is stamped on the connection for the right-hand half of the tank and an upright rectangle is stamped on the connection for the left-hand half of the tank.
On the 5 Series (E39) it is not possible to drain off fuel via separate connections. In this case, the fuel must be drained off via the filler tube (tank neck).