Location |
A1/1 | Instrument cluster (IC [KI]) control unit |
S54.30-4596-03
Task
The instrument cluster (IC) control unit provides information about dynamic and static vehicle states. If faults occur, appropriate warnings are emitted.
The following displays are possible:
Permanent displays (e.g. vehicle speed, rotational speed, tank contents)
Indicator lamps (green, yellow or blue) (e.g. turn signals, high beams)
Warning lamps (red) (e.g. coolant level, brake fluid level)
Multifunction display (e.g. driver assistance systems, menu sequence)
To output warning and indicator tones, the instrument cluster (IC) control unit actuates the instrument cluster speaker in the driver footwell.
S54.30-4606-79
Block diagram (with engine 200 or engine 699) |
A1/1 | Instrument cluster (KI) control unit | N15/3 | Electronic transmission control (EGS) control unit (with automatic transmission) | |
A1/1e1 | Left turn signal indicator light | N15/9 | Rear-axle differential lock control unit (with code A71 (Rear-axle differential lock)) | |
A1/1e2 | Right turn signal indicator light | N30/4 | Electronic Stability Program (ESP) control unit | |
A1/1e3 | High beam indicator lamp | N45 | Transfer case control unit (VG) (with code ZG3 (Engageable all-wheel drive with gear reduction) or with code ZG4 (Permanent all-wheel drive with gear reduction)) | |
A1/1e4 | Fuel reserve indicator lamp | N50 | Fuse and relay module control unit (SRM) | |
A1/1e6 | Brake fluid and parking brake indicator lamp | N62 | Parktronic (PTS) control unit (with code EZ8 (PARKTRONIC)) | |
A1/1e9 | Seat belt warning lamp | N75 | Driver assistance systems control unit (with code BA3 (Active Brake Assist) or with code JA9 (Traffic Sign Assist) or with code JW5 (Lane Keeping Assist) or with code EZ8 (PARKTRONIC)) | |
A1/1e11 | Parking brake indicator lamp | N80 | Steering column tube module (MRM) control unit | |
A1/1e15 | Supplemental restraint system indicator lamp | N87/6 | Radio (Audio/COMAND) | |
A1/1e16 | Preglow indicator lamp (with diesel engine) | N88/1 | Tire pressure monitor (TPM [RDK]) control unit (with code RY2 (Tire pressure monitor (TPM))) | |
A1/1e17 | Anti-lock braking system indicator lamp | N93 | Central gateway (CGW) | |
A1/1e31 | Standing lamps indicator lamp | N110 | Weight Sensing System (WSS) control unit | |
A1/1e32 | ESP®/ASR OFF warning lamp | N112/9 | HERMES control unit (with code EY5 (Mercedes-Benz emergency call system)) | |
A1/1e41 | Electronic Stability Program warning lamp | N118 | Fuel system control unit (FSCU) | |
A1/1e43 | DISTRONIC warning lamp (with code BA3 (Active Brake Assist)) | N135 | Steering wheel electronics | |
A1/1e46 | Parking brake indicator lamp | N153 | 360° camera control unit (with CODE JS1 (360° camera)) | |
A1/1e47 | Rear fog lamp indicator lamp | S1 | Light switch | |
A1/1e51 | Brake system warning lamp | S110 | Left multifunction steering wheel button group | |
A1/1e54 | Coolant temperature warning lamp | S111 | Right multifunction steering wheel button group | |
A1/1e57 | Front fog lamp indicator lamp (with code L16 (Front fog lamps, halogen)) | X11 | Diagnostic connector | |
A1/1e58 | Engine diagnosis indicator lamp | CAN A | Telematics CAN | |
A1/1e66 | Tire pressure monitor warning lamp (with CODE RY2 (Tire pressure monitor)) | CAN D | Diagnostic CAN | |
A1/1e67 | Low beam indicator lamp | CAN E | Chassis CAN | |
A1/1e70 | Power steering warning lamp | CAN HMI | User interface CAN | |
A1/1p13 | Multifunction display | CAN PER | Peripherals CAN (with code BA3 (Active Brake Assist) or with code JA9 (Traffic Sign Assist) or with code JW5 (Lane Keeping Assist) or with code EZ8 (PARKTRONIC)) | |
A40 | Audio/COMAND control panel | CAN V | Vehicle CAN | |
B84/8 | Multifunction camera (MFK) control unit (with code JA9 (Traffic Sign Assist) or with code JW5 (Lane Keeping Assist)) | LIN E1 | Steering LIN | |
B162 | Collision warning system radar sensor (with code BA3 (Active Brake Assist)) | LIN E2 | Seat occupied recognition LIN | |
H4/61 | Instrument cluster speaker | Ethernet | Ethernet | |
N2/18 | Supplemental restraint system (SRS) control unit | A | Mercedes-Benz | |
N3/33 | CDI control unit (with engine 699) | B | Nissan | |
N3/34 | ME-SFI [ME] control unit (with engine 200) | C | Default | |
N10/1 | Signal acquisition and actuation module (SAM) control unit | D | Optional | |
N14 | On-board electrical system management system control unit (with code MJ8 (ECO start/stop function)) |
General function
The following subfunctions can be performed at the instrument cluster (IC) control unit:
Activate instrument cluster (IC) control unit.
Indicator and warning lamp test
Workshop level settings
Display operating states.
Comfort displays
Trip computer (TRIP)
Control and warning messages
Activate instrument cluster (IC) control unit
The instrument cluster (IC) control unit is activated by unlocking the vehicle.
Indicator and warning lamp test
The indicator and warning lamp test is executed automatically every time circuit 15 is switched on.
For this test, all the indicator and warning lamps, except the indicator lamps for the exterior lights, the turn signal lights and preglowing, are actuated before the engine starts.
Workshop level settings
The following submenus are accessible in the "Workshop level" menu:
"Vehicle data" menu
"Dynamometer test" menu
"Change brake pad" menu
"ASSYST PLUS" menu
Location |
1 | Main menu button |
2 | Accept call button |
3 | OK button |
4 | Scroll forward/back button |
5 | Back button |
G82.90-0001-75
The "Workshop level" menu is activated as follows:
Close doors.
Without code FX9 (KEYLESS Go): Turn ignition key to position "1".
With code FX9 (KEYLESS Go): Switch on circuit 15 by briefly pressing KEYLESS-GO start/stop button (S2/3).
Do not operate the service brake while doing so.
With code FX9 (KEYLESS Go): Switch on circuit 15R by briefly pressing KEYLESS-GO start/stop button (S2/3) again.
Do not operate the service brake while doing so.
Press Main menu button (1) repeatedly until the "Trip" menu item is shown on the multifunction display is highlighted by a bar, then press the OK (3) button to confirm.
The multifunction display must show the standard display (trip distance/total distance) as seen in the picture. If necessary, repeatedly press one of the scroll forward/back buttons (4).
First press and hold down "Accept call" button (2) and then, within 1 second, also press and hold down OK button (3) for 5 seconds.
The multifunction display shows the workshop menu with the menu items "Vehicle data", "Dynamometer test", "Brake pad replacement" and "ASSYST PLUS".
Press either the forward or back button (4) repeatedly until the required menu is highlighted with a bar and confirm with OK button (3).
"Vehicle data" menu
The following data can be called up in the vehicle data menu:
Voltage (in volts) and power consumption (in amps) in on-board electrical system
Data from the instrument cluster (IC) control unit (e.g. version numbers, software releases)
Engine data (e.g. engine number)
Vehicle identification number (VIN)
"Dynamometer test" menu
Activating the "Dynamometer test" menu prevents faults being entered in the Electronic Stability Program (ESP) control unit (N30/4) during the brake test on the roller dynamometer.
If the "Dynamometer test" menu is not deactivated before the workshop menu is exited, it will automatically be called up during the next ignition cycle.
"Change brake pad" menu
The "Change brakepad" menu is used to move the pistons of the brake calipers to the assembly position.
"ASSYST PLUS" menu
The following submenus can be called up in the "ASSYST PLUS" menu:
Service data
Full service
"Vehicle handover"
"Oil measurement"
Display operating conditions
The display of the operating states includes the following subfunctions:
Display of vehicle speed
Display of engine speed
Displaying coolant temperature
Display of travel distance
Display of fuel quantity
Gear display and drive program display (with automatic transmission)
"ECO" display (with code MJ8 (ECO start/stop function))
Transport mode display
Display of vehicle speed
The Electronic Stability Program (ESP) control unit transmits the wheel speed signals to the instrument cluster (IC) control unit. From these it calculates the vehicle speed, compares it with the internally stored speedometer characteristic and then actuates the speedometer accordingly via a stepper motor.
Display of engine speed
The CDI control unit or the ME-SFI control unit transmits the engine speed signal to the instrument cluster (IC) control unit. This actuates the tachometer accordingly via a stepper motor.
Displaying coolant temperature
The CDI control unit or the ME-SFI control unit transmits the coolant temperature signal to the instrument cluster (IC) control unit. This actuates the coolant temperature display accordingly.
The coolant temperature gauge is actuated via a correction characteristic. This correction characteristic defines the following temperature ranges in which the coolant temperature display is actuated in different ways:
0 to 80 °C: The actual coolant temperature is displayed. However, the display only appears above 40 °C.
80 to 115 °C: The coolant temperature display constantly shows a value of 90 °C.
115 to 120 °C: The coolant temperature display constantly shows a value of 95 °C.
120 to 130 °C (start of red warning range): The coolant temperature display shows the actual coolant temperature.
At coolant temperatures > 130 °C the instrument cluster (IC) control unit also actuates the coolant temperature warning lamp. An appropriate warning appears in the multifunction display. If the instrument cluster (IC) control unit does not receive a value for the coolant temperature, it actuates the coolant temperature warning lamp. The coolant temperature gauge is then not actuated.
Display of travel distance
The instrument cluster (IC) control unit uses the wheel speeds to calculate the traveled distance, taking the tire circumference into consideration.
Display of fuel quantity
The fill level of the fuel tank is registered by the fill level sensor integrated in the fuel pump with fuel delivery module. The fuel pump control unit (FSCU) sends the corresponding signal to the central gateway (CGW) control unit and from there to the instrument cluster (IC) control unit. This actuates the fuel display accordingly.
When the reserve range is reached, the instrument cluster (IC) actuates the fuel reserve warning lamp. An appropriate message additionally appears in the multifunction display.
The reserve range is defined by comparing the measured fill level with the tank characteristic stored in the instrument cluster (IC) control unit. If the reserve level has dropped to approx. 50 %, a gasoline pump symbol is displayed in the "Range" menu instead of the distance reading.
Display characteristics of fuel level indicator:
After circuit 15 is switched on, the current fill level is displayed.
In the first 4 s after engine start, the display value is updated every 0.8 s in order to obtain a value under the full on-board electrical system voltage. Thereafter, the display is updated via a dampening.
A defective fill level sensor is detected by comparing the change in the fill level of the fuel tank with the calculated average consumption. An appropriate message appears in the multifunction display.
Gear display and drive program display (with automatic transmission)
The electronic transmission control (EGS) control unit transmits the gear and drive program information to the instrument cluster (IC) control unit. This produces the gear display and the drive program display in the multifunction display.
"ECO" display (with code MJ8 (ECO start/stop function))
The CDI control unit or the ME-SFI control unit transmits the status of the ECO start/stop function to the instrument cluster (IC) control unit. The operational readiness of the ECO start/stop function is indicated to the driver by the "ECO" symbol in the multifunction display.
Transport mode display
When transport mode is activated, the message "Transport mode" and the charge level of the on-board electrical system battery are shown in the multifunction display in the form of a bar graph with 40 stages.
Comfort displays
The comfort displays provide a quick overview of the following information:
Display of outside temperature
Display of time
Scale illumination of instrument cluster (IC) control unit
Display of outside temperature
The SAM control unit transmits the outside temperature to the instrument cluster (IC) control unit.
The following parameters must be considered in addition so that the actual outside temperature is displayed:
Vehicle speed (falsification of value through air stream)
Coolant temperature (falsification of value through radiant heat)
The CDI control unit or the ME-SFI control unit transmits information about the coolant temperature to the instrument cluster (IC) control unit.
The coolant temperature values exert the following influence on the outside temperature display:
Coolant temperature < 60 °C:
The current outside temperature value is always shown.
Coolant temperature > 60 °C and "Engine running" or "Drivetrain operational" signal is set:
At vehicle speeds < 20 km/h (with vehicle deceleration), the outside temperature display is only changed if the measured outside temperature value drops.
At vehicle speeds from 20 to 45 km/h, rising outside temperatures are displayed after a delay period of 3 min.
At vehicle speeds > 45 km/h, rising outside temperatures are displayed after a delay period of 90 s.
The Electronic Stability Program (ESP) control unit calculates the vehicle speed from the wheel speeds and transmits the calculated vehicle speed to the instrument cluster (IC) control unit.
Coolant temperature > 60 °C and "Engine running" or "Drivetrain operational" signal is not set:
A delay period of max. 1 h prevents an apparently high outside temperature from being displayed due to the heat radiated from the engine. A rise in display value is not permitted during this delay period. At "circuit 15 OFF" the last measured outside temperature value is stored and then displayed when the circuit is reactivated.
If the outside temperature has dropped below the stored value in the meantime, the currently measured temperature is displayed after 8 s.
The display range for the outside temperature is between -40 and 85 °C or between -40 and 185 ℉.
If the instrument cluster (IC) control unit receives implausible values for the coolant temperature or it does not receive any values at all, the outside temperature display is controlled as if the coolant temperature were > 60 °C.
Display of time
The radio (Audio/COMAND) transmits information about the time to the instrument cluster (IC) control unit.
Scale illumination of instrument cluster (IC) control unit
The scale illumination is switched on when the instrument cluster (IC) control unit is activated. The brightness is automatically adapted to the ambient brightness by the instrument cluster (IC) control unit.
Trip computer (TRIP)
The trip computer provides data and information on average fuel consumption, trip time, average speed, travel distance and range, which it displays as follows:
"After start" (short-distance memory)
"After reset" (long-distance memory)
"Current fuel consumption"
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 information is displayed in the multifunction display of the instrument cluster (IC) control unit as follows:
"Traveled distance"
"Time elapsed"
"Average consumption"
"Average trip speed"
The TRIP computer includes the following subfunctions:
Display of distance after start/reset
Display of time after start/reset
Display of average speed
Display of present consumption and average consumption
Range display
Display of distance after start/reset
The travel distance "After start" is displayed in the range from 0 to 9999 km.
The travel distance "After reset" is calculated similar to the travel distance "After start"; however, the display here is in the range from 0 to 99,999 km.
Display of time after start/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 in the same way as the time after start, although the display in this case is in the range from 0 to 9999 h and 59 min.
Display of average speed
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.
Display of present consumption and average consumption
The CDI control unit or the ME-SFI control unit transmits information about the fuel consumption to the instrument cluster (IC) control unit. This calculates the current consumption and the average consumption.
Range display
The expected range is calculated from the ratio between the current tank content and the average fuel consumption.
Control and warning messages
The messages shown on the multifunction display are split up into 4 categories according to their level of urgency:
Category 1 (messages with highest priority):
Category 1 messages refer to states and situations which endanger safety, and they take priority over messages with low 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 acoustic warning is emitted over the instrument cluster speaker.
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 warning tone is emitted over the instrument cluster speaker.
Category 3 and 4 (messages with low priority):
These messages only serve as information for the driver (e.g. low washer fluid level). No warning chime is emitted.
If several messages with the same priority occur, the message currently displayed is cross-faded by the new message after expiry of the minimum display time.