Bus Communication: Notes

The E46 cluster is part of a vehicle bus network which includes the following bus systems:

• Controller Area Network  - The CAN bus supplies the cluster with information to operate the tachometer and fuel economy gauge. The "TD" (engine speed) and the "ti" (injector on time) signals are now sent to the cluster as part of the CAN-Bus signals rather than independent dedicated signals as before. The transmission range, program and fault indicator signals are also now a part of CAN-Bus information as well. This further reduces the wiring requirement and increases reliability.
• Body Bus  - The K-bus provides the cluster with a connection to other vehicle systems such as the LSZ, IHKA and GM. Signals are shared between these systems which allow for a reduction in sensors and switches.
• Diagnosis Bus  - The D-bus allows diagnostic communication between the vehicle and the diagnostic equipment. The cluster provides a "gateway" to connect the D-bus and other bus networks.