D-Bus System

The D-Bus is a serial communications bus that transmits data between the DISPlus and the connected control units. The control unit subject to diagnosis is selected by sending a diagnosis telegram to the control unit address. By request from the DISPlus, the control unit transmits information and the contents of the fault memory or activates a control unit output.

The D-Bus is only active when the DISPlus or GT1 is connected to the diagnostic socket and communicating.

• D-Bus is connected to power train (emission) related control units.
• DS2 Protocol Bus is connected to control units that do not affect emissions and the IKE. Through the IKE communication with the entire K-Bus is possible.

The normal operating voltage of the D-Bus is 12 volts even though it can support communication with as low as 2 volts. The voltage measurement is taken from each data line connection to ground. Each module on the D-Bus provides its own voltage used for communication.

D-Bus operation and signals are similar to K-Bus.