GF54.30-P-3043RIA Comfort Displays, Function

GF54.30-P-3043RIA Comfort Displays, Function

General function requirements
^ Instrument cluster (A1) activated

General convenience display function sequence
The convenience displays permit a rapid overview of information which is not required for operating the vehicle
The convenience display function consists of the following subfunctions:
^ Outside temperature indicator function sequence
^ Time display function sequence
^ Instrument cluster illumination function sequence

Outside temperature indicator function sequence
The outside temperature is recorded by the outside temperature indicator temperature sensor (B14), read in by the driver-side SAM control unit (N10/10) and forwarded to the instrument cluster via interior CAN.
The outside temperature is shown in the left multifunction display (A1p13).
In order to determine a correct value of outside temperature, the following parameters must also be taken into account:
- Vehicle speed (distortion of value by the airstream)
- Coolant temperature (distortion of the value by radiant heat)

The coolant temperature values have an influence on the outside temperature indicator as follows:

Coolant temperature T < 60 °C:
The current outside temperature value is always displayed.

Coolant temperature T > 60 °C and circuit 61 On:
At a speed of v < 20 km/h the display only changes if the measured outside temperature value decreases. At speeds between v = 20 km/h to v = 45 km/h rising outside temperatures are displayed after a delay period of t = 3 min.
At speeds > 45 km/h, rising outside temperatures are displayed after a delay period of t = 90 s.

If the vehicle speed signal is faulty, increasing temperatures are displayed every t = 10 min in a buffered manner.

Coolant temperature T > 60 °C and circuit 61 Off:
A delay period (t = max. 1 h) prevents that an apparent increased outside temperature is displayed due to heat dissipated from the engine. A rise in display value is not permitted during this delay period.

Coolant temperature T < 60 °C and circuit 61 Off:
If the coolant temperature drops below the value of T = 60 °C, the delay period does not apply. Increasing temperatures are then displayed again.
The display range is between -40 and +85 °C

If the instrument cluster receives implausible or no outside temperature values, then the display of outside temperature is controlled as if the coolant temperature were T > 60 °C.

The coolant temperature sensor (B11/4) is read in by the ME-SFI [ME] control unit (N3/10) and transferred to the instrument cluster via engine compartment CAN.

Time display function sequence
The time (24 hour military format) is displayed digitally via the electronic clock (A70) in the center console.

On vehicles with code (512) COMAND APS with DVD changer or code (527) COMAND APS with single DVD drive (with navigation), the system time is automatically synchronized via the navigation system integrated in the COMAND operating, display and controller unit (A40/3) and transmitted to the instrument cluster via interior CAN.

The instrument cluster transmits the data to the electronic clock via Local Interconnect Network (LIN).

On vehicles with code (528) COMAND with DVD changer, the time is set using the left multifunction steering wheel button group (S110) and right multifunction steering wheel button group (S111).

Instrument cluster illumination function sequence
The illumination is switched on automatically when the instrument cluster is activated.
If the instrument cluster is activated via the opening of the driver's door, the illumination switches off again after t = 30 s. If an active warning is displayed then the run-on time extends by a further t = 2 minutes.
The brightness is automatically adjusted to suit the lighting conditions in the interior compartment by brightness sensors in the instrument cluster.

If the rain/light sensor (B38/2) transmits the "night signal", the instrument cluster switches to night mode.
The signal of the rain/light sensor is read in by the overhead control panel control unit (N70) and transmitted via the interior CAN to the instrument cluster.
Depending on the light falling on the brightness sensors, the instrument cluster automatically regulates the lighting in a range between 80 and 100 % of the maximum brightness.
The brightness can also be changed individually by turning the instrument illumination brightness control and reset button (A1r1) if the exterior lights are switched on.

When the exterior lights are switched off, only the brightness of the left multifunction display and right multifunction display (A1p15) is automatically adapted by the brightness sensors. Manual adjustment via the brightness control is not possible in this case.