GF54.30-P-3041CW Display Operating Conditions, Function
GF54.30-P-3041CW Display Operating Conditions, Function
Function requirements:
^ Instrument cluster (A1) activated
Function sequence for displaying operating conditions
The Display operating conditions function consists of several subfunctions. These are:
^ Vehicle speed display
^ Engine rpm display
^ Coolant temperature display
^ Fuel quantity display
^ Travel distance display
^ Gear indicator (only with transmission 722)
^ Engine oil level display
Vehicle speed display
Additional function prerequisites
^ Circuit 15 On
Function sequence for vehicle speed display
The wheel speed determined by the rpm sensors (L6/1, L6/2, L6/3 and L6/4) is read by the Electronic Stability Program control unit (N30/4) and placed on the chassis CAN. The instrument cluster calculates the current speed based on the values received. This is compared with a stored speedometer characteristic and displayed in the speedometer (A1p8) by means of a stepper motor.
The instrument cluster makes the determined speed value available to other vehicle systems, both on the interior CAN and on the chassis CAN.
Engine rpm display
Additional function prerequisites
^ Circuit 61 On
Function sequence for engine rpm display
The crankshaft speed recorded by the crankshaft position sensor (L5) (with engine 646, 271) or crankshaft Hall sensor (B70) (with engine 642, 272) is read by the ME-SFI [ME] control unit (N3/10) (with gasoline engine) or by the CDI control unit (N3/9) (with diesel engine) and placed on the chassis CAN.
The instrument cluster receives this data and actuates the tachometer (A1p5) accordingly by means of a stepper motor.
Displaying coolant temperature
Additional function prerequisites
^ Circuit 15 On
Function sequence for coolant temperature display
The coolant temperature recorded by the coolant temperature sensor (B11/4) is read by the ME-SFI [ME] control unit or CDI control unit and placed on the chassis CAN.
The instrument cluster actuates the stepper motor for the coolant temperature gauge (A1p1) accordingly.
The coolant temperature gauge is actuated based on a correction characteristic. This correction characteristic defines 4 temperature ranges in which the coolant temperature gauge is actuated differently.
^ T = 0 °C to 80 °C:
The actual temperature is displayed. There is no display until the temperature reaches T = 40 °C.
^ T = 80 °C to 115 °C:
The pointer constantly points at T = 90 °C.
^ T = 115 °C to 120 °C:
The pointer constantly points at T = 95 °C.
^ T = 120 °C to 130 °C (start of red warning range):
The actual temperature is displayed.
At coolant temperatures of T > 130 °C, the coolant temperature warning lamp (A1e54) is also permanently actuated and a warning message is output by the instrument cluster.
If a defective engine fan is detected, the actual values are displayed. At the same time, the coolant temperature warning lamp is permanently actuated.
If the instrument cluster does not receive a coolant temperature, the coolant temperature gauge is not actuated. At the same time, the coolant temperature warning lamp is permanently actuated.
Fuel quantity display
Additional function prerequisites
^ Circuit 15 On
Function sequence for fuel quantity display
The fill level measured by the left fuel level indicator sensor (B4/1) and right fuel level indicator sensor (B4/2) is read by the rear SAM control unit with fuse and relay module (N10/2) and forwarded to the instrument cluster via the interior CAN. The values received are evaluated using a tank characteristic and displayed on the fuel level indicator (A1p2) by means of a stepper motor.
If the reserve range has been reached (approx. 12.5 % of the maximum tank content), the fuel reserve warning lamp (A1e4) comes on. A warning message also appears in the multifunction display.
If the reserve range has dropped to approx. 50%, a gasoline station symbol in the form of a gasoline pump is shown in the range menu instead of the travel distance.
Display behavior:
^ Display with engine OFF:
After circuit 15 ON, the current fill level is displayed on the fuel level indicator. In the process the pointer runs up in a damped manner.
^ Display after engine start:
The display value is updated every t = 0.8 s for t = 4 s, to obtain a value under full on-board voltage. After this time, or as soon as the vehicle starts off, the display is updated with a delay.
^ Display with circuit 15 OFF:
After circuit 15 OFF, the pointer of the fuel level indicator gradually returns to zero.
Travel distance display
Additional function prerequisites
^ Circuit 15 On
Function sequence for travel distance display
The travel distance display function consists of several subfunctions. These are:
^ Calculation of mileage
^ Display of main odometer reading
^ Display of trip distance
^ Saving mileage counts
Calculation of travel distance:
The wheel speed determined by the rpm sensors is read by the Electronic Stability Program control unit and placed on the chassis CAN. The instrument cluster calculates the travel distance based on the values received in combination with the tire size. Tire size is coded using STAR DIAGNOSIS.
Display of main odometer reading:
This is displayed in the multifunction display or travel distance display.
The maximum main odometer reading displayed is 999,999.
Display of trip distance:
This is displayed in the basic display of the Trip menu in the multifunction display or in the travel distance display. The maximum trip distance reading displayed is 9999.9. If this value i reached, the counter starts again from zero. In contrast to the main odometer reading, the trip odometer disappears from the display if another vehicle function is active.
The trip distance counter can be reset to zero by pressing the Reset and "Back" button (S110s7) without code (442) Comfort multifunction steering wheel or the OK button (S110s6) with code (442) Comfort multifunction steering wheel in the left multifunction steering wheel button group (S110) for t > 3 s.
Retention of counter data:
The main odometer reading is continuously stored in the permanent section of the internal memory. This memory ensures that the counter reading is retained for at least 5 years, even if the power supply is disconnected. The current reading of the trip odometer is also stored in the permanent memory of the instrument cluster.
However, the current counter reading is not transferred from the temporary memory to the permanent memory until there is a circuit change from circuit 15 ON to circuit 15 OFF.
Gear display
Additional function prerequisites
^ Circuit 15 On
Function sequence for gear indicator
The current gear and current transmission mode are displayed in the multifunction display or on the gear indicator (A1p12) (without code (442) Comfort multifunction steering wheel). The required data are transmitted via the chassis CAN by the following control units:
^ Fully integrated transmission control control unit (Y3/8n4) (with transmission 722.9) or
^ Electronic transmission control control unit (N15/3) (with transmission 722.6)
Engine oil level display
Function requirements:
^ Circuit 15 On
Function sequence for engine oil level display
The oil level check switch (S43) monitors the engine oil level. This is read by the ME-SFI [ME] control unit or CDI control unit.
If necessary, the ME-SFI [ME] control unit or CDI control unit transmits a message to the instrument cluster via the chassis CAN.
The instrument cluster then displays the corresponding message in the travel distance display or multifunction display.
