GF54.30-D-3018HL Display Fuel Quantity, Function

GF54.30-D-3018HL Display Fuel Quantity, Function

- except CODE (JK3) High-end instrument cluster with speedometer in km

General
The fuel level and reserve indicator (A1p2) is located at the bottom of the display (A1p1) in the instrument cluster (A1) and is a 6-segment LCD bargraph indicator. The fill level of the fuel level and reserve indicator is displayed immediately with "circuit 15 ON".
A hysteresis is applied in order to prevent continuous activation and deactivation of a segment used to represent a display value which is close to a segment limit. There are 2 fixed actuation thresholds for each of the 6 segments. The segment is activated when a threshold value is overranged and the segment is deactivated when another threshold value is underranged. This prevents a segment from flickering.

Updating of the fuel level and reserve indicator for "circuit 15 OFF"
If the vehicle is refueled with "circuit 15 OFF", the fuel level and reserve indicator is updated when the "circuit 15 ON" state exists again, provided that approx. 3 liters of fuel have been added.

Updating of the fuel level and reserve indicator for "circuit 15 ON"
With "circuit 15 ON", the current tank content is displayed on the fuel level and reserve indicator.
If the vehicle is refueled with "circuit 15 ON", the fuel level and reserve indicator is not updated until approx. 7 liters of fuel have been added.

The fuel level and reserve indicator is always updated after a delay. This ensures that fluctuations in the fuel level resulting from vehicle movement are not shown on the fuel level and reserve indicator.

Reserve range
If the reserve range is reached, the fuel reserve/tank cap indicator lamp (A1e30) lights up yellow. The lamp is triggered with a delay period to prevent the lamp flickering. If the fuel level is less than 12.5 % of the tank capacity, the fuel reserve/tank cap indicator lamp is actuated.

Networking and information flow
Networking of components:
- With engine 642 or with engine 646, the fuel level sensor of the fuel pump with fuel level sensor (M3/5) is read in and evaluated by the SAM control unit (N10).
- With engine 272, the fuel level sensor of the fuel pump with fuel level sensor (M3/6) is read in and evaluated by the SAM control unit.
- The SAM control unit places the signals on the Controller Area Network bus class B (interior) (CAN-B).
- The instrument cluster reads in the signals from CAN-B.
- The instrument cluster evaluates the values read in from the fuel level sensor using a tank characteristic. The fuel level and reserve indicator and, if necessary, the fuel reserve/tank cap indicator lamp are then actuated accordingly on the basis of these values (which are calculated according to the type of tank used).

Fuel tank sensor tight installation recognition
The jammed fuel tank sensor recognition function becomes active after the vehicle has covered a distance of s > 160 km. Fuel tank sensor tight installation is detected when the sensor resistance value does not change by at least a defined sensor resistance value within a certain distance.
If this state occurs, an erroneous bit is set for the fuel level sensor in the fault memory of the instrument cluster. The erroneous bit is deleted again if the required change in the resistance value of the fuel level sensor has occurred.

If the values displayed in the fuel level and reserve indicator are implausible, the tank evaluation algorithm can be initialized by the instrument cluster by causing an open circuit in circuit 30.