Instrument Cluster / Carrier: Description and Operation
Instrument Cluster (Redesign) Check-Control Module (K/CC):
Notes:
This section applies to the instrument cluster with check-control as of February 1989 (instrument cluster redesign high).
Functional Description:
General:
The instrument cluster "instrument cluster redesign high" is a further development of the instrument cluster installed up to February 1989.
Important modifications compared to old version:
- Additional ASC indicator lamp (8) between tachometer and speedometer
- Coding plug no longer in wire harness, but now integrated in unit.
- Turn signal indicator sound generator on pc-board
- Km/miles reading is indicated with the ignition switched off when the trip odometer reset button (5) is depressed
- Integrated system test
- Improved diagnostic facilities
Modifications as of September 1990:
Further modifications have been introduced on the instrument cluster as of September 1990. The individual chapters in this section provide relevant information. The units as of 9/90 have a software status greater than 0.90 (read out with BMW Diagnostic System or Label on reverse side of unit).
Analog Instruments:
Fuel gauge (1): The immersion tube sensing unit in the fuel tank displays the amount of fuel in the tank. An indicator lamp in the fuel gauge lights when the fuel level drops below approx. 8 litre. The fuel gauge reading is switched to zero when the reserve lamp lights.
The indicator lamp is damped "electronically", i.e. flutter of the lamp due to movements of the fuel is suppressed.
As of 9/90, the reserve lamp is switched on for approx. 2 seconds after switching on the ignition (lamp test)
Speedometer (2): The signals from the rear axle Reed contact (tachogenerator) are processed in the instrument cluster. The signals are processed separately for displaying vehicle speed and distance covered.
Tachometer (3): The TO-signal (engine speed signal) is processed by the DME control unit.
Temperature gauge (4): This gauge indicates the coolant temperature.
KVA gauge (fuel consumption indicator) (9): The TI-signal (injection signal) of the DME control unit and the vehicle speed signal are processed here. The current fuel consumption is calculated from both values.
As of September 1990 (= introduction of a new engine wire harness), the fuel consumption on the M 70 engine will be calculated from both ti-signals.
Oil temperature gauge (9): An oil temperature gauge is installed in models E34/M5 instead of the KVA indicator.
Buttons in the Instrument Cluster:
Left button (5): Reset of trip odometer. Indication of the km/miles reading for 25 seconds when the button is depressed with the ignition switched off.
Right button (CC button) (10): Clearing check-control display or BC texts. If several check-control messages are pending simultaneously, the individual messages are called up by successfully pressing the button. Start of system test.
Display Unit (6):
The display unit, also referred to as the instrument cluster display, consists of an LCD module (LCD = Liquid Crystal Display). It contains:
- Service interval display
- Total mileage (km) display
- Trip mileage (km) display
- Program and range display (automatic transmission)
- Check-control texts
- Text output of on-board computer
Photoelectric sensor (7):
The brightness of the display unit is adjusted electronically to the ambient light. The brightness in the vehicle is sensed by the photoelectric sensor. The brightness can also be varied with the manual dimmer when the vehicle lights are switched on.
Coding Plug:
The coding plug is plugged into the instrument cluster. It basically consists of a voltage-independent electronic memory. This memory contains all specific vehicle data which the instrument cluster requires to process and display the signals.
The total mileage and the service interval data are also stored in the memory.
The coding plug can be renewed only by breaking oft the plug cover. This cover is then replaced by a cover supplied with the replacement coding plug. Installation of a replacement plug is indicated in the diagnostic program (*D* status lists: Instrument Cluster) and during the integrated test.
Coding plug as of 9/90 (Software > 0.9):
The memory has been extended to cope with additional data. The coding plugs up to 9/90 and as of 9/90 have different part numbers, the coding plugs as of 9/90 feature a blue housing. Due to mechanical coding, it is not possible to interchange the pc-board and coding plug.
Coding Plug Code:
The code is printed on a label on the reverse side of the coding plug. The code is also indicated in the diagnostic program (*D* 210 Status lists: Instrument Cluster) and during the integrated test.
Languages:
The German language (for messages in the display unit) is preset in the instrument cluster after disconnecting and reconnecting the battery. Any other language can be selected by operation.
Operation:
- Switch ignition lock to position R (position 1)
- Press CC button (right) until a language designation appears in the display unit
- Release CC button
- Press CC button again, next language is displayed
- Repeat procedure until the required language is selected
This language remains stored until the battery is disconnected and reconnected.
The languages available are German, US English, UK English, French, Italian and Spanish.
Position of Indicator Lamps:
Note! Modified indicator lamp functions as of September 1990:
Indicator lamps up to September 1990:
Number Indicator lamp Source
1 Left turn signal indicator Relay
2 High beam Light switch
3 Right turn signal indicator Relay
4 Trailer turn signal Relay
indicator
5 ASC lamp ASC control unit
5 on M5 Sports symbol
engine
6 Battery charge indicator Alternator
7 EML warning lamp EML control unit
8 Oil pressure Pressure switch
9 Seat belt (USA and Gulf Belt contact switch
States only)
10 Check engine (USA only) DME control unit
11 Fog light Fog light switch
12 Rear fog light Fog light switch
13 Handbrake Handbrake switch
14 General brake warning Pressure switch and level
switch for brake fluid
15 ABS indicator ABS control unit
16 Airbag Airbag control unit
17 Tank reserve Immersion tube sending unit
with electronic damping in
instrument cluster
Indicator lamps as of September 1990:
Number Indicator lamp Source
1 Left turn signal indicator Relay
2 High beam Light switch
3 Right turn signal indicator Relay
4 Trailer turn signal indicator Relay
5 ASC lamp ASC control unit
5 on M5 Sports symbol
engine
6 Seat belt (USA and Gulf Belt contact switch
States only)
7 EML warning lamp EML control unit
8 Oil pressure Pressure switch
9 Battery charge indicator Alternator
10 Check engine (USA only) DME control unit
11 Fog light Fog light switch
12 Rear fog light Fog light switch
13 Handbrake Handbrake switch
14 General brake warning Pressure switch and
level switch for brake
fluid
15 ABS indicator ABS control unit
16 Airbag Airbag control unit
17 Tank reserve Immersion tube sending
unit with electronic
damping in instrument
cluster
Lamp Self-Test:
The lamps for brake warning (14), handbrake (13), oil pressure (8) and battery charge Indicator (6/9) light when the ignition is switched on. They go Out when the engine starts.
The airbag (16) indicator lamp lights for approx. 6 seconds after the ignition has been switched on. The EML (7) and ASC (5) indicator lamps light for 1 second after the ignition has been switched on.
Depending on the ABS system installed, the indicator lamp for ABS (15) is either switched on permanently till the engine starts or for 2 seconds after switching on the ignition.
As of 9/90 (software status greater than 0.9), the tank reserve lamp (17) will switch on for approx. 2 seconds after switching on the ignition.
Integrated Test Facilities:
Important data and the system test can be read out or triggered without diagnosis.
Procedure:
- Switch oft ignition.
- Press CC button (right button) and hold depressed.
- Switch on ignition.
- Release CC button when the first output appears in the display unit.
Display Explanation:
BMW No. Internal number
CODE No. Code number of coding plug
K-NUMBER Distance factor for speedometer
F.G. No. Chassis number
SW. VERS. Software version
Rev. INDEX Revision index (hardware version)
- If the coding plug is a replacement plug, the red replacement marking lights during the display (red LED).
A system test is triggered on completion of these outputs.
System Test:
- All segments and the lighting of the instrument cluster display unit are switched on. Also the red LED for replacement identification!
- The pointers of the speedometer and tachometer are set to the center position.
- The pointers of the fuel gauge, temperature gauge and consumption gauge (KVA) (oil temperature for M5) each move, within 5 seconds, from the zero position to the end position and back.
- The warning lamps for brakes, tank reserve and seat belt (seat belt only for US version) are switched on.
- Corresponding to the display in the speedometer, a vehicle speed signal (speed-A signal) is transferred to other control units.
The internal test procedure is terminated on completion of the system test. It can, however, be terminated at any time by pressing the CC button.
Check-Control:
General:
The check-control (CC) is a comprehensive system of messages which inform the driver of various operating status's. The display is provided as a text message in the display unit and is accompanied by an acoustic signal (gong).
A large number of sensors monitor the individual vehicle systems and components. Three systems are responsible for acquiring and outputting the data to the evaluation logic:
Instrument cluster (K): Covers all systems which also include an indicator lamp in addition to the text message. All acquired data are evaluated in the instrument cluster and, after fulfilling the display conditions, are output in the form of a text message on the display unit.
Check-control module (CCM): Covers a large number of systems. Connection to the instrument cluster is made via three data links. By way of data transfer, the check-control module constantly informs the instrument cluster of the status of the connected systems.
Lamp control module (LKM): The light relays are accommodated in the light control module. The lighting system and the brake light switch are monitored for detects. The lamp control module (LKM) communicates with the CCM via data links. The CCM forwards the data to the instrument cluster (refer to Diagnostic Procedure LKM).
Priority Groups:
The CC messages are subdivided into three priority groups.
- Priority 1: Faults which directly endanger driving safety. Indicated by flashing indicator arrows. Message cannot be canceled with CC button.
- Priority 2: Faults which do not directly endanger driving safety. Message can be canceled with CC button and is also canceled automatically after 2 minutes.
- Priority 3: Messages relating to liquid/fluid levels. They are displayed only when switching the ignition on and off and are canceled after 20 seconds.
List of Check-Control Messages:
The list provides an overview of check-control messages. Listed are the contents of the message and not the defect in the display unit. Individual messages which have the same preconditions (.e.g. lamps) are listed in combined form. The "condition" column indicates which prerequisites are required in addition to the defect status so that the message is displayed. The message and reset signal columns indicate the type of signal of the generator system.