The CANBUS is an electronic communications network that interconnects electronic components within a car or other vehicle. Due to the specialised requirements and need for Fail-Safe reliability; conventional computer networking techniques (ethernet and TCP/IP) are not used
Engine Control Modules (ECM)
Transmission Control Modules (TCM)
Anti-Lock Braking System (Abs) Modules
Air Bag Systems
Keyless Car Entry Or Security
Advanced Climate Control
Motorized Seats And Mirrors That Remember The Settings Of Multiple Drivers
Unique Signal Processing
Each control module needs to speak to the other modules comprising the network. The wiring and relay switching necessary to achieve this would be extremely complex and would prevent easy installation of additional sensor modules. The Canbus system identifies each module as a 'Node' on the network and gives it a unique 'Address' or fingerprint. Any module needing to communicate with it will send a signal identified with the target node address. All other modules will ignore this signal.
Using this technique many signals can be sent simultaneously over the same network.
The Canbus can also allow certain devices to over-ride or suppress less important functions during emergencies. For example; during emergency breaking or impact then driver and passenger safety are paramount so the ABS and Airbag Systems will override other systems.