Instrument cluster (IC), networking of components - GF54.30-P-0002-06PP
Valid up to 30.6.02
Valid as of 1.7.02
The instrument cluster (A1) is connected to the Controller Area Network bus class C (engine compartment) (CAN-C) and the Controller Area Network bus class B (interior) (CAN-B). Data is exchanged with the necessary control units via CAN-C and CAN-B.
However, the instrument cluster (A1) does not serve as an interface between the CAN-C and CAN-B. This function is reserved for the EIS [EZS] control unit (N73).
On models as of 1.7.02 the data from the multifunction steering wheel (MFL) is no longer read in via the electronic ignition switch control unit (N73) but via the steering column module (N80).
Data from multifunction steering wheel (MFL) buttons
As the buttons of the multifunction steering wheel (MFL) have several functions, the data from these buttons must be processed as follows:
- All the buttons of the left multifunction steering wheel button group (S110) and right multifunction steering wheel button group (S111) are read in by the electronic ignition switch control unit (N73) voltage-coded.
- The electronic ignition switch control unit (N73) places the corresponding messages on the CAN-B.
- This data is read in by the instrument cluster (A1).
- The instrument cluster (A1) links this data with the current display in the multifunction display (A1p13) and places this data dependent on the current display as a message for the respective control units on the CAN-B. This combination is necessary as the function of many buttons is dependent on the current adjustments in the multifunction display (A1p13).
Function of multifunction steering wheel (MFL) buttons in an example
If the + and - button, adjustment of specific functions and volume control (S111s1) of the multifunction steering wheel (MFL) is pressed, then the user normally expects the volume of the audio system to change.
However, if the multifunction display (A1p13) happens to be displaying an adjustment (e.g. OFF delay time for interior light), then this adjustment is changed when the + and - button, adjustment of specific functions and volume control (S111s1) is pressed. The volume of the audio system is not changed.
Connections
Due to the connection of the instrument cluster (A1) to the CAN-C and CAN-B the number of connections, including the voltage supply, reduces to the following connections:
- CAN-C low
- CAN-C high
- CAN-B low
- CAN-B high
- Kl.31
- Tml. 30
- Tml. 15