vehicle dashboard If you’ve purchased a car in the last 20 years, part of its operation involves computerized functions. All models manufactured today have at least one computer, which typically oversees emissions and receives information from various sensors.

Collectively, this system of wires and software is referred to as the Controller Area Network (CAN). The CANbus connects all your vehicle’s computers and sensors and creates a far more advanced and economical system than it would with physical wires alone.

With these points in mind, what should you know about your car’s CANbus?

Types of Computers

These days, vehicles usually have multiple computers, each allocated to a particular function:

  • Automatic transmission
  • Anti-lock brakes
  • Air bags
  • Keyless entry or security
  • Advanced climate control
  • Motorized seats and mirrors
  • Radio or CD player with a digital display
  • Cruise control

Models may be equipped with as many as 50 microprocessors, which make diagnosing issues and making repairs easier. Your car may also have sensors for the following:

  • Oxygen
  • Air pressure
  • Air temperature
  • Engine temperature
  • Throttle position
  • Pressure
  • Voltage
  • Acceleration
  • Rolling

How It All Works

Your car’s CANbus is frequently compared to a freeway, with data moving between devices. Electronic Control Units (ECUs) act as signals to control the flow, particularly for the sensors related to the engine, transmission, windows, doors and other systems. Information never truly stops, with roughly 2,000 signals being transmitted at any time.

Unlike with your home or workplace network, your car has no router or hub. Rather, the ECUs simultaneously listen for signals and information as they carry out requested actions. These anticipated requests essentially allow the CAN to run as smoothly as possible.

Along with operation, information from the sensors further helps your car operate more efficiently and economically. For instance, the ECUs assist with controlling and monitoring fuel injectors, spark plugs and idle speed to improve your car’s performance and reduce emissions.

Compare all of this to past operations, where signals were communicated over wires. As vehicles became more advanced, models sported miles of thick cords all over. With a CAN, two systems – for instance, the seat heaters and the switch to operate them – don’t need direct wiring. Rather, communication simply occurs over the network.

While programming a car continues to be a complex endeavor, this switch offers a handful of key benefits:

  • Your car physically weighs less
  • It’s more reliable, as it has fewer wires that will fray and break
  • Issues are easier to diagnose and may simply require software updates


For professionals, diagnoses are made through the On-Board Diagnostics protocol (OBD-II). These universal procedures help with a car’s self-diagnosis. A CAN needs to connect to all engine sensors, then the ECU looks out for questionable signals before sending an OBD-II code to the network. Once the ECU identifies a problem, your car’s check engine light comes on. One of these checks occurs every time you start your car.

When you bring your car into the shop, a mechanic reads the diagnostic code from the computer and from here, knows how to fix the issue. If your manufacturer discovers a programming issue or wants to update the car’s operations, they’ll use the same port. In all cases, a technician just has to plug a computer into the port to add new software.

Up-to-date on the latest technological advances, the team at DaSilva’s Auto Body is ready to diagnose and repair your car when the check engine or another light come on. If you need to have your car assessed, contact our Naugatuck location to make an appointment today.