Overview
This document contains the following information:
General
Function requirement
Instrument cluster control
Message management
Service interval processor
Trip computer
Driving style analysis
General
The instrument cluster control actuates all the displays in the instrument cluster display. The instrument cluster displays all drive-relevant information, e. g. fuel supply, engine speed and coolant temperature. Furthermore, the driver is shown actions, recommendations and malfunctions of the systems installed in vehicle.
Function requirement
Circuit 15R ON
Instrument cluster control
For display control in the instrument cluster, the instrument cluster control system communicates with the respective systems over the vehicle's network architecture. The instrument cluster control system evaluates the incoming data and converts the information in the data for display on the instrument cluster. The image data is transferred via the high speed video link (HSVL) to the instrument cluster display.
The instrument cluster control system also processes the following information:
Terminal 15 status
Fuel supply
Engine speed
Coolant temperature
Outside temperature
Requests to display system information
Requests to output warnings
Information on the on-board electrical system utilization
Message management
The instrument cluster control system divides all incoming requests for displaying messages into four categories appropriate to their level of urgency.
Category 1 (messages with highest priority):
Category 1 messages refer to states and situations which impair safety, and they take priority over messages with lower priority. These messages are displayed within max. 2 s after they occur, stored automatically in the message memory and cannot be acknowledged. When they occur, a brief warning tone is sounded.
Category 2 (messages with medium priority):
Category 2 messages require the intervention of the driver and appear after a delay of max. 2 s. These messages also include operating feedback. Category 2 messages can be acknowledged. When they occur, a brief warning tone is sounded.
Category 3 and 4 (messages with low priority):
These messages are shown in the menu and they are only for providing information to the driver (e.g. low washer fluid level). No warning chime is emitted.
Messages with low priority are overlaid by messages with high priority. If several messages with the same priority occur, the message currently displayed is overlaid by the new message after the minimum display time has elapsed.
Service interval processor
The service interval processor is integrated into the instrument cluster control system. It determines the respective service due dates based on the vehicle's usage conditions. The instrument cluster shows either the remaining time or the remaining distance to the service due date.
The driver or service personnel are also provided with an overview of the service work that needs to be carried out on the vehicle. The service interval processor takes into account the time and distance-dependent additional operations.
Trip computer
The trip computer is integrated into the instrument cluster control system. It analyzes the handling characteristics and shows the driver among other things the following information:
Travel distance
Driving time
Average speed
Average fuel consumption
Present consumption
Trip computer information can be shown in the following display screens:
After start (short-distance memory)
After reset (long-distance memory)
Driving style analysis
The driving style analysis is integrated into the instrument cluster control system. It evaluates the after start handling characteristics up to the end of the journey and, with the ECO display, it supports a driving style that provides for optimum fuel consumption.
The individual handling characteristics are displayed graphically on the ECO display. The following information is displayed:
Acceleration characteristic
Uniformity of driving style
Deceleration and coasting characteristics
Function schematics | |||
Function schematic for displaying operating statuses in instrument cluster display | Model 447.8, 448 | ||
Function schematic for displaying trip information in instrument cluster display | Model 447.8, 448 | ||
Control units | |||
Head unit/instrument cluster displays, basic function | |||
Instrument cluster control unit, basic function | |||
Head unit control unit, basic function |