Bit-Serial Data Interface (BSD)

Bit-Serial Data Interface (BSD)

The bit-serial data interface is a single-wire data bus with a data transfer rate of 1.2 kBd.

The following components are connected across the bit-serial data interface with the DME/DDE control module:
- Alternator
- Oil condition sensor (depending on variant)

Function
The following data is interchanged between the DME/DDE and the connected components:
- Function commands from the DME/DDE to the components
- Identification data of the components to the DME/DDE
- Operating values of the components and their functions to the DME/DDE
- Fault messages of the components to the DME/DDE

Diagnosis
The DME/DDE monitors the communication across the bit-serial data interface to the connected components. This means that wire faults are also detected.

The connected components have their own diagnosis functionality and monitor the following:
- The executed functions are monitored for faults (e.g. defective preheating circuit for the combustion preheating control module)
- Internal faults in the components

If a component detects a fault, it reports the fault across the bit-serial data interface to the DME/DDE. The DME/DDE then enters the fault in the fault memory.