Automobiles started using the Controller Area Network or CAN bus in the late 1990s. The controller area network permits a vehicle's onboard computers to communicate with each other on a high-speed bus. It provides a path for computer modules to share sensor information with other modules. Sharing sensor information saves on plugs and wiring. We connect to the CAN network through the DLC or Data Link Connector.
Shielding protects the signal in wiring from outside electrical interference. For example, the wiring in a vehicle's CAN network often has foil or braided shielding protecting signal integrity. They also contain the signals, preventing them from crossing over to other circuits.
Manufacturers also use twisted-pair wiring. Twisting two wires together reduces interference. Twisted-pair wiring may be shielded or unshielded, depending on the application. Wire insulation keeps the signal contained but does not offer the same protection from outside interference as shielding.