Bus Communication

Bus Communication

System overview
For a more detailed description of the car's bus system, see "Bus and diagnostics communication", System overview. See Powertrain Management/Computers and Control systems/Information Bus


Diagnostics communication
In a bus system, all units must be capable of communicating with each other. For example, the engine cannot be started unless the Trionic T7 system can receive the immobilization information sent out by the TWICE.

Permanent bus faults
All diagnostics communication with systems connected to a bus takes place via the DICE. Irrespective of which system is contacted, the diagnostic tool will first check with the aid of the DICE that all systems in the car connected to a bus are awake and in communication. If any control module connected to a bus is missing, diagnostic trouble codes will be generated. The cause of the fault could be that the control module concerned has lost its power supply or one of the bus leads.

The SPA uses the following information







The SPA transmits the following information