Diagnostic Bus
The Diagnostic bus system is made up of two separate bus-systems which allow the DISplus to communicate with the vehicle control units via the diagnostic socket:
- The Diagnostic bus (ISO 9141-2 OBD II):
- This allows communication with the DISPlus and powertrain (emission) related control units
- The DS2 Protocol bus:
- This connects to the control units that do not affect emissions and to the instrument cluster (IKE), which enables communication with all the control units on the K-Bus system
The Diagnostic bus uses a single wire transmitting at 9,600 bits per second. The diagnostic line is used by DISPlus to interrogate each control unit on the network and helps in the fault finding process. It uses a protocol very similar to that of the K-Bus system and is accessed by DISPlus via the 16 pin diagnostic connector located in the driver's footwell (under the dash, close to the A post).