Bus Communication

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

Diagnostics
In a bus system, it is necessary for all the units to be able to communicate with each other. For example, the engine cannot be started unless Trionic T7 can receive immobilizer information transmitted by TWICE.

Permanent bus faults
All communications between the diagnostic tool and systems on the bus take place via DICE. Irrespective of which system is being contacted, the diagnostic tool, with the help of DICE, will make sure that all the systems on the bus are active and communicating. The diagnostic tool will indicate any control modules missing from the bus. This means that all the control modules are communicating correctly on the bus unless the diagnostic tool warns otherwise.

Intermittent bus faults
Trionic continuously checks to see that TCM and MIU are communicating correctly. Diagnostic trouble codes will be generated if an intermittent fault should occur in the bus communication. The cause of the fault could be that the power supply or one of the bus leads to a control module is missing

Missing control module Diagnostic trouble code
TCM P1923
MIU P1908

Trionic T7 uses the following Information:







Trionic T7 transmits the following information: