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Trip computer, function - GF54.30-P-3044RF

Model 205, 253 

Function requirements, general 

IMPORTANT The electronic ignition lock control unit (N73) transmits the status of circuit 15 via the user interface CAN (CAN HMI) to the instrument cluster (A1).

Trip computer (TRIP) function, general 

The trip computer provides data and information on average fuel consumption, trip time, average speed, travel distance and remaining range.

The trip computer provides the following display screens:

The information displayed refers to the point in time of the last reset of the short-distance memory ("After start") or of the long-distance memory ("After reset").

The "After start" or "After reset" information is shown on the multifunction display (A1p13) of the instrument cluster as follows:

The TRIP computer includes the following subfunctions:

Function sequence, travel distance display after start/after reset 

The travel distance is calculated on the basis of the wheel speeds. The Electronic Stability Program control unit (N30/4) transmits the information about the wheel speed via the chassis FlexRay (Flex E), the electronic ignition lock control unit and the user interface CAN to the instrument cluster. The instrument cluster calculates the traveled distance from the wheel speeds. The travel distance "After start" is displayed in a range of 0 to 9999 km.

IMPORTANT If a period of more than t = 4 h lies between the time when circuit 15 is switched off and then switched on again, then the "After start" odometer is automatically reset to "0".

IMPORTANT If the odometer reading is between 6213 and 9999 and the distance unit is changed (e.g. from km to miles), the odometer will automatically be reset to "0". This reset remains active even if the unit is changed again. Distance units are changed in the "settings" menu in the "instrument cluster" submenu. The distance unit can be changed from km to miles in the "speedometer/travel distance display unit" display window.

The "After reset" travel distance is calculated in the same way as the "After start" travel distance, apart from the fact that a range of 0 to 99, 999 km is displayed.

Depending on the setting in the instrument cluster and coding of the national version of the instrument cluster, the travel distance is displayed in:

IMPORTANT Switching over from kilometers to miles causes an automatic switchover from liters to gallons.

Function sequence, time display after start/after reset 

With circuit 15 ON, the time after start is added up by means of a time counter. The display ranges from 0 to 999 h and 59 min.

The time "After reset" is determined analog to determining the time "After start", though here the display takes place in a range of 0 to 9999 h and 59 min.

Function sequence for the average speed display 

The trip computer calculates the average speed from the ratio between the travel distance driven and the time passed (trip time) since the last reset of the short-distance memory or long-distance memory. The travel distance is calculated in the instrument cluster from the wheel speeds.

Depending on the setting (kilometers/miles) and the national variant coding of the instrument cluster the average speed is displayed in:

Function sequence for display of present consumption (except model 205.086/087/286/287) and composite mileage 

The CDI control unit (N3/9) (diesel engine) or the ME-SFI [ME] control unit (N3/10) (gasoline engine) transmits information about fuel consumption via the engine CAN (CAN C), the powertrain control unit (N127), the chassis FlexRay, the electronic ignition lock control unit and the user interface CAN to the instrument cluster.

The trip computer uses this data to calculate the following information:

Depending on the setting (kilometers/miles) and the national variant coding of the instrument cluster the fuel consumption is displayed in:

IMPORTANT The present consumption is displayed together with the range. The display is in the form of a bar.

Function sequence for remaining distance display 

The trip computer determines the expected range from the ratio between the current tank capacity and the average fuel consumption.

The fill level of the fuel tank is recorded by the left fuel tank fuel level indicator fill level sensor (B4/1) and the right fuel tank fuel level indicator fill level sensor (B4/2).

The fuel system control unit (N118) reads in the signals of the fuel tank fuel level indicator fill level sensors and transmits information about the fill level of the fuel tank via the drive train CAN (CAN C1), the powertrain control unit, the chassis FlexRay, the electronic ignition lock control unit and the user interface CAN to the instrument cluster.

Function sequence for display reset 

The TRIP computer is reset in the "Reset values" menu by pressing the OK button. (S110s6) in the left multifunction steering wheel button group (S110). Here, the reset is only carried out for the currently displayed information.

The steering wheel electronics (N135) read in the status of the OK button directly and transmit it to the steering LIN (LIN E1) to the steering column tube module control unit (N80). The steering column tube module control unit transmits the status of the OK button via the chassis FlexRay, the electronic ignition lock control unit and the user interface CAN to the instrument cluster.

Function sequence for power flow display (model 205.012/047/147/212/247) 

Fig 1: Display - Power Flow Information Screen
G10133685Courtesy of MERCEDES-BENZ USA

The power flow display on the instrument cluster shows whether energy is being taken from or added to the high-voltage on-board electrical system. The data that is required for the display is transmitted by the battery management system control unit (N82/2) via the hybrid CAN (CAN L), the powertrain control unit, the chassis FlexRay, the electronic ignition lock control unit and the user interface CAN to the instrument cluster.

  Electrical function schematic, instrument cluster trip computer   PE54.30-P-2057-97FBA
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