Instrument Functions Part 2
Instrument Functions
Diagnosis
The instrument cluster is a diagnostic compatible system. Diagnosis and reading out of the fault memory in the instrument cluster are possible with the MoDiC or DISplus via the K-CAN SYSTEM data bus. The instrument cluster also has test functions, which are read out in its display.
On-board diagnosis: The instrument cluster carries out on-board diagnosis in order to monitor function and identify faults. Identified faults are stored if they have been detected three times as "true". New faults are not taken into consideration when the memory is full. Faults which no longer occur after 40x terminal 15 ON/OFF are automatically deleted when the memory is full. The fault memory can be read out with the diagnostic unit or in the instrument cluster display.
Test functions: The listed test functions can be displayed in the instrument cluster when the trip odometer reset button is pressed. The indication appears in the left display area inside the speedometer with an orange backlighting.
Calling up test functions:
- With terminal R (radio setting) or terminal 15 ON, press the trip odometer reset button for longer than five seconds or
- with terminal R switched off, press and hold down the trip odometer reset button and switch on terminal R.
Displaying test functions:
- Identification :01
- System test :02
- (not occupied) :03
- Consumption :04
The test function number is increased each time the trip odometer reset button is briefly pressed.
A maximum of four test functions can be shown simultaneously.
Except for test functions 1 and 2, all test functions must be unlocked by means of test function 19.
Starting selected test function: Press trip odometer reset button for longer than two seconds.
Displaying selected test function: The selected test function is displayed inside the rev counter.
Terminating test function:
- Switch off terminal R (radio setting) or
- Press trip odometer reset button for longer than six seconds.
NOTE: After completing the tests, lock the test functions in accordance with test function 19.
CC Check Control
The Check Control is a message system that reports faults in the vehicle and at the same time serves to display operating states and instructions.
- The message texts (max. 40 characters) contain clear instructions.
- In parallel with the CC messages, further information (max. 170 characters) pertaining to the current message can be called up or appear automatically in the on-board data menu of the control display.
- In addition to German, there are another 10 languages in which the texts can be displayed.
Display locations:The Check Control signals are displayed at several locations by fixed and variable indicator lamps in the instrument cluster.
- Variable indicator lamps light up yellow or red below the gear display. The time and the outside temperature normally displayed at this location are overwritten as required by the Check Control.
- Check Control text messages are displayed below the rev counter. Data from the on-board computer which are already located at this position when the message is output are overwritten.
Most of the Check Control messages have supplementary explanations and instructions available in the control display. These explanations and instructions can be called up via the on-board data menu or are automatically displayed in particularly serious situations.
Display behavior: Check Control messages are usually announced by a gong. The output takes the form of
- a text message with a fixed and/or variable indicator lamp,
- the text being featured in the display area below the rev counter and usually with an additional explanation in the control display or
- a non-text message with a fixed indicator lamp.
If several text messages are poised to be output simultaneously or if one indicator lamp is to be activated simultaneously by various non-text messages, the message with the highest priority is displayed first.
In addition to the visual display, the Check Control alerts the driver with acoustic signals. Depending on the importance of the accompanying message, a gong or a double gong of differing volume and tone sounds. Depending on its cause, the acoustic warning is issued from the left or right front car speaker.
Operation:The Check Control messages can be called up with the CC button on the turn indicator/dipping lever. This is possible by:
- scrolling through with brief button pressing or
- switching back and forth in the display area below the rev counter between the on-board computer and the Check Control.
The display automatically reverts to its initial state (rendering dark or on-board computer) eight seconds after the last button operation.
It is not possible to render the display dark if the Check Control is showing a top-priority message (e.g. engine overheating) or the fuel gauge indicates low fuel.
On-board computer
The on-board computer is installed in the control display and is operated with the controller. This computer contains assorted subfunctions.
"Main"on-board computer:The "main" on-board computer will be referred to simply as the on-board computer in the following.
Displays: The computer supplies from terminal R data for the following displays:
- Distance:The distance can be input via the controller into the computer. The distance value is then counted down by the computer or transmitted by the navigation system to the instrument cluster. In this case, the navigation system calculates down to "0". In both case, the instrument cluster continues counting the "minus distance".
- Range: The range is calculated from a mean consumption value and the tank content. Stationary periods while the engine is running and sudden changes in driving style are compensated in the calculation to the greatest possible extent.
- Arrival time: The arrival time is calculated from the distance, the time and a mean driving speed. The calculation is made in such a way that the displayed value changes minute by minute without sudden jumps. The arrival time can only be calculated if the clock has been set and a distance has been manually input. If the distance value has been adopted by the navigation system, permanent calibration is performed by the routing system on the basis of the road map data. This method makes it possible for the system to estimate the arrival time much more accurately.
- Average fuel consumption: The average consumption is calculated using the data from the consumption and travel memory. The calculation always begins with a manual reset. The display appears after the first travel pulse.
- Average speed: The average speed is calculated using the data from the travel memory and timer. The calculation always begins with a manual reset. The display appears after the first travel pulse.
A reset of average consumption and speed is carried out via the controller directly in the menu of the on-board computer in the control display. A dialog window appears in the display shield when one of these displays is selected. Selective resetting is possible with the dialog window.
Individual information from the on-board computer can be displayed in the instrument cluster.
Display field below speedometer: This field can display distance and/or range; in addition tank content.
Display field below rev counter: This field can display arrival time, average fuel consumption and average speed; in addition total and trip distance traveled or present consumption.
The additional displays can be called up in the control display.
The stop watch, limit and memo functions and the timer for independent heating/independent ventilation are only displayed in the control display.
When the car is started, the information that was selected last is always shown in the display areas of the instrument cluster.
No function of the on-board computer can be displayed below the rev counter while a Check Control message is being displayed there. Such a display is only possible after a specified minimum display time has elapsed or after the message has been cancelled by button operation. A top-priority message cannot be removed.
Operation: The displays of the on-board computer can be called up and scrolled through with the buttons on the turn indicator/dipping lever. This is possible by:
- Long-term pressing of the top button switches back and forth in the display area below the rev counter between Check Control and on-board computer. Brief pressing scrolls through their functions.
- Brief pressing of the lower button scrolls through all the display options below the speedometer. Long-term pressing renders both displays dark.
It is not possible to render the display dark if a Check Control message is active or the fuel gauge indicates low fuel.
Both display fields are rendered bright or dark simultaneously. They cannot be rendered individually.
Trip computer: The trip computer serves to monitor individual stages, which can also be stopped or interrupted. The trip computer must be selected and activated in the on-board computer menu in the control display. The information of the trip computer is only displayed in the control display. It is not possible to display this information in the display fields of the instrument cluster.
The following are displayed by the trip computer:
- start time and start date
- Driving time and distance traveled
- Average fuel consumption and average speed
The trip computer is activated with the controller in the START selection field.
When a journey is interrupted, from terminal 15 OFF further calculation of the average values is discontinued (provided START or STOP is activated) and only started again when the journey is resumed.
The displays are frozen with the STOP selection field. Further calculation is no longer possible after the displays are frozen. Selecting START again resets all the displays of the trip computer jointly. Selective resetting of individual function is not possible with the trip computer.
Limit: A speed limit can be entered in the on-board computer via the controller and the control display. The entry can be made manually with the controller or the speed currently being driven can be adopted. The area above the input speed is represented inside the speedometer scale is represented by a bright circle segment. When the speed exceeds the input value, this is indicated by a gong and a Check Control message.
The function is ready for operation from terminal R ON. The warning when the input limit is exceeded can only be output in driving mode (terminal 15 ON and travel pulse telegram). The current speed limit and the associated activation status are stored in the instrument cluster also after terminal 15 OFF.
Stop watch: The stop watch function is ready for operation from terminal R. A running stop watch is stopped with terminal R OFF. The stop watch starts running again with terminal R ON.
The stop watch is started and stopped with the controller via the selection fields in the control display. A time interval can be called up when the stop watch is running. The maximum running time of the stop watch is 99 hours and 59 minutes. The stop watch remains at this value when this time has elapsed.
Settings: The following additional functions can be controlled via the on-board computer and displayed in the control display:
- Clock:The date and time must be manually input via the controller in the control display. The time is calculated and displayed in the instrument cluster. The time is also indicated in the control display.
The time cannot be overlaid in the instrument cluster. The time features together with the indicated outside temperature in the LCD display field below the gear display. The display appears provided it is not overwritten by a variable Check Control indicator lamp.
- Memo signal: If the MEMO function has been activated and a time is set, the instrument cluster triggers from terminal R ON an hour signal 15 seconds before each full hour has elapsed. The function can be activated and deactivated in the control display.
- Timer for independent heating and independent ventilation:Two timers are fitted for each of the independent heating and independent ventilation functions. The timers are set in the A/C menu of the control display. The values for time, timer ID code and status are transmitted to and stored in the instrument cluster. At the prespecified time, the function is transmitted to the IHKA and the IHKA is activated.
The functions "independent heating ON", "independent ventilation ON" and "automatic selection independent heating/independent ventilation" are possible-depending on the outside temperature. The ID code for the function is selected in the IHKA.
- Code:A code can be entered from terminal R ON in the Settings menu of the control display which prevents the engine from being started by unauthorized persons.
During a starting attempt, the instrument cluster identifies the stored information "code armed" and issues an input prompt via the Check Control. Only when the control display has confirmed input of the valid code to the instrument cluster does the instrument cluster signal enabling of engine starting to the DME control module.
- Unit conversion: Units can be converted by means of encoding with the Tester or at the control display. Usually entire display groups are converted here.
Country-specific version
The instrument cluster comes in different hardware versions for the following markets:
Europe
- Speedometer with km/h scale
- Rev counter for gasoline engine with scale to 7000 rpm
- 4 MB memory capacity
Europe with extended languages
This version contains additional characters for Japan, Korea, Taiwan.
- Speedometer with km/h scale
- Rev counter for gasoline engine with scale to 7000 rpm
- 8 MB memory capacity
Europe and US market
- Speedometer with mph scale
- Rev counter for gasoline engine with scale to 7000 rpm
- 4 MB memory capacity
Languages and units
Languages and units can be set via the control display.
Languages: The following languages are stored in the 4 MB language memory of the instrument cluster:
- German
- English (UK)
- English (US)
- French
- Italian
- Dutch
- Spanish
In addition to the above mentioned languages, the following languages are stored in the 8 MB language memory of the instrument cluster:
- Japanese
- Korean
- Chinese, traditional
- Chinese, simple
Units: The following units are stored in the instrument cluster:
- Temperature in degree C and in degree F
- Consumption in mpg US, mpg UK, km/l, l/100 km
- Date/time format for US and Europe
- Travel in km and miles
Language encoding
Language encoding: Depending on the language encoding of the CAS Car Access Systems, a language package is programmed in the control display which contains three of the above mentioned languages.
From these three languages, one language can be selected for the control display.
The settings can be stored as a key memory function. In this ways, the units and languages stored are displayed as a function of the key used (user).
K-CAN SYSTEM BUS
The instrument cluster communicates with control modules in the chassis and suspension, drive and body sections via the K-CAN SYSTEM data bus in the form of telegrams. The following information/data are transmitted:
- Speed: Telegram for displaying the vehicle speed and calculating the distance covered.
Signal path: Left rear wheel sensor -> DSC control module -> PT-CAN -> ZGM -> K-CAN SYSTEM -> instrument cluster
- Transmission data: Telegram for displaying gear position, selected driving program and CC messages.
Signal path: EGS control module -> PT-CAN -> ZGM -> K-CAN -> instrument cluster
- Engine speed: Telegram for displaying the engine speed.
Signal path: DME -> PT-CAN -> ZGM -> K-CAN SYSTEM -> instrument cluster
- Outside temperature: Telegram with a mean outside temperature value for processing in other control modules. A value calculated in the instrument cluster from the current engine temperature and vehicle speed. It prevents the outside temperature signal from being excessively influenced by the air stream and waste engine heat.
Signal path: e.g. instrument cluster -> K-CAN -> CD and/or IHKA
- CBS Condition Based Service messages: Telegrams from DME, DSC and IHKA with information on the current level of component wear. They are needed in the instrument cluster for the calculation of CBS displays and service dates.
- FAS turn indicator/dipping lever: Signal from FAS from terminal 30 with each operation of FAS.
Signal path: FAS -> SLZ steering column switching center -> BYTEFLIGHT bus -> ZGM -> K-CAN -> as telegram among others to instrument cluster
- Driving direction: Signal for displaying the selected driving direction in the instrument cluster.
Signal path: LM light module -> K-CAN SYSTEM -> as telegram to instrument cluster and AHM trailer module
- Bus status: Telegram with information on the status (bus active or in rest state) of the K-CAN SYSTEM data bus.
Signal path: ZGM central gateway module -> instrument cluster
- Dimming: Signal with information on the adjusted brightness.
Signal path: Dimmer control wheel -> LM light module -> as telegram to instrument cluster
- Driver's display, rpm range: Signal for displaying the variable rpm warning zone in the instrument cluster display.
Signal path: DME -> PT-CAN -> ZGM -> K-CAN SYSTEM -> instrument cluster
- EMF parking brake: Telegram with information for the parking brake indicator lamp on the status of the EMF electromechanical parking brake.
Signal path: EMF control module -> PT-CAN -> ZGM -> K-CAN SYSTEM -> instrument cluster
- Vehicle identification number: Telegram with the last seven positions of the VIN for redundant data storage for the allocation of instrument cluster and car. Signal path: CAS -> K-CAN SYSTEM -> instrument cluster
Signal path: CAS -> K-CAN SYSTEM -> instrument cluster
- Vehicle type: Telegram with details of the vehicle type (model series, body type, transmission, engine, steering, country-specific type) for the allocation of the different vehicle versions and instrument cluster.
- Kilometer reading/range: Telegram with information for creating the fault memory entries (total distance traveled, tank fill level - right, left, total, reserve, calculated range).
Signal path: Instrument cluster -> K-CAN SYSTEM -> further control modules
- Terminal status: Telegram with details of the relevant terminal status (terminal R, terminal 15, terminal 50, key inserted).
Signal path: CAS -> K-CAN SYSTEM -> instrument cluster
- Lamp status: Telegram with details on the relevant status of lamp activation for high beam/headlight flasher, parking light, front fog lamps, rear fog light.
Signal path: LM -> K-CAN SYSTEM -> instrument cluster
- LCD luminance: Telegram with a value calculated in the instrument cluster from the values of phototransistor and potentiometer (position of dimmer control wheel). The telegram is used by other control modules as a dimming signal.
Signal path: Instrument cluster -> K-CAN SYSTEM -> control modules: CDC, SZL (switch illumination), LM
- Engine data: The telegram contains the engine data: engine temperature (corresponding to coolant temperature), engine oil temperature, engine oil pressure, alive counter of DME (function monitoring of DME), engine running status, injected fuel quantity (total of output fuel quantity).
Signal path: DME -> PT-CAN -> ZGM -> K-CAN SYSTEM -> instrument cluster
- K-CAN network management: This telegram is transmitted and received by each control module. Each control module has a control module address which it using when transmitting and from which it identifies a network management message.
- RDA request/data storage: Telegram with the current data from redundant data storage.
Signal path: CAS-> K-CAN SYSTEM -> instrument cluster and instrument cluster -> K-CAN SYSTEM -> CAS
- Power management, battery voltage: The telegram contains details on: battery voltage and status of battery master switch.
Signal path: Power module -> K-CAN P -> K-CAN SYSTEM -> instrument cluster
- Relative time: The relative time is determined by a timer running synchronously to the system/on-board clock. The telegram with the relative time is used in other control modules for time calculation. The time of the on-board clock cannot be used for time recording because the clock can be set. The timer starts after a reset (e.g. disconnection of vehicle battery) at zero and counts up second by second. The DME determines the stationary time of the engine from the relative time terminal R OFF to terminal R ON again.
- Status, trailer: The signal indicates whether a trailer is electrically connected.
Signal path: AHM -> K-CAN SYSTEM -> instrument cluster
- Status, damper program: The telegram indicates the status of EDC-K Electronic Damper Control (continuous) and is monitored by the instrument cluster. A corresponding fault message is displayed in the event of EDC-K malfunction.
Signal path: EDC-K -> PT-CAN -> ZGM -> K-CAN SYSTEM -> instrument cluster
- Status, DSC Dynamic Stability Control program: The telegram contains status messages of the DSC program and fault messages.
Signal path: DSC control module -> PT-CAN -> ZGM -> K-CAN SYSTEM -> instrument cluster
- EMF alive counter: The telegram is used for EMF function monitoring by the instrument cluster. A corresponding fault message is displayed in the event of a parking brake control module malfunction.
Signal path: EMF control module -> PT-CAN -> ZGM -> K-CAN SYSTEM -> instrument cluster
- Time/date: The telegram contains the date and time and is transmitted to other control modules (e.g. to the wiper module for calculating the APS alternating park position).
Signal path: Instrument cluster -> K-CAN SYSTEM -> other control modules
- Status, radio key: The telegram contains the personalization number of the radio key and the status of the key battery.
Signal path: CAS -> K-CAN SYSTEM -> instrument cluster
- Status, instrument cluster: The telegram contains: displayed vehicle speed, unit speed km/h or mph, washer fluid fill level, status - vehicle speed controller interface, status - airbag warning lamp, relative timer, status - belt warning lamp, status - engine warning lamp, status - DSC indicator lamp, status - brake warning lamp, status - parking brake indicator lamp.
Signal path: Instrument cluster -> control modules: DME, SIM and wiper module
- ZV and lid status: The telegram contains details of the central locking status, central locking control and the status of the door contacts and rear lid. The signals are needed for displaying the CC messages relating to the positions of doors, rear lid and central locking.
Signal path: CAS control module -> K-CAN SYSTEM -> instrument cluster
Security function
Load cutout
The display heater is cut in/out by the power module as a function of the system voltage.