Automobile Computers

For twenty years, since 1996, cars have used computers to control different parts of the car.

You might wonder, why computers in cars? Computers are more reliable and use fewer wires than mechanical equivalents.

The computers, however, are not desktop, laptop, tablet, or phone computers we’re used to. They’re micro computers more like a Raspberry Pi, a set of chips with software loaded into memory. Each computer talks to other computers connected together into a network.

Several network types are used in cars based on what they control. For example, important controls like the dashboard, navigation, and engine use a Computer Area Network (CAN) with messages passed back and forth. Each computer in a CAN is able to process messages. Controls like turn signals don’t require complicated robust networks like CAN. They use a Local Interconnect Network (LIN) which has a master computer connected to subordinate computers, called slaves. There are other networks in cars, for example, a network to manage safety devices and newer types like FlexRay.

Which computers and networks exist in a car depends on the auto manufacturer and age of the car. Today the 18-80 computers found in cars are connected with cables. In the future, most likely wireless networks will be used.

Anybody can see the data their car generates, in real time, using a plug that connects to your car and broadcasts diagnostic data to an app on your phone or tablet. These plugs range in price from $15 to $100 USD. The more expensive plugs include better security transmitting data to your app, faster response rates, and in some cases, more data. The low cost plugs use a common ELM327 chipset with basic functionality.

This diagram from the print magazine shows some of the key controls and networks found in automobiles.



Learn More

On Board Diagnostics (OBD)

Engine Control Unit (ECU)

The Computer Area Network (CAN) Bus

Local Interconnect Network (LIN) Network

Automotive Safety Restraints (ASRB) Network

FlexRay Network


Use your iPhone to Scan Vehicle Codes And Read Sensor Data

Car Hacking Tools of the Trade

The title is overly dramatic but this book excerpt explores different options for seeing message traffic and sensor data in your car. Lots of useful context.


  • Tim Slavin

    Tim is an award-winning writer and technologist who enjoys teaching tech to non-technical people. He has many years experience with web sites and applications in business, technical, and creative roles. He and his wife have two kids, now teenagers, who are mad about video games.

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