Bus Communication

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

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

Permanent bus faults
All communication between the diagnostic tool and systems connected to the bus takes place through DICE. Irrespective of which system is contacted, the diagnostic tool first checks by means of DICE that all on-board systems connected to the bus are turned on and in communication. If any control module connected to the bus is missing, the diagnostic tool will show this. This means that all control modules connected to the bus can communicate properly unless the diagnostic tool warns otherwise.

Intermittent bus faults
Trionic continually checks that the TCM, MIU and TC/ABS communicate correctly. If intermittent faults on the bus communication occur, fault codes will be generated. The cause of the fault can be that the control module in question has lost its power supply or one of the bus lines.

Missing control module DTC
TCM P1923
MIU P1908
TC/ABS P1925

The Trionic T7 uses the following information:





The Trionic T7 sends out the following Information: