Bus communication: Diagnostics: Notes
WARNING: This page is about a different car, the 2003 Saab 9-3 and 2002 Saab 9-3. However, it is still accessible from the selected car via links, so may be relevant.
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.