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AUTOMOTIVE NETWORKS · GOTECH

CAN bus explained

CAN lets vehicle modules share information. Start with that idea, see how the wiring changes a test, then follow a real fault through the diagnosis.

Understand CAN communication →Diagnosing a fault? Start with the case →

Three free lessons. Compare diagrams, follow the cases and try three reasoning checks in each lesson. Use the video when you want to see the original explanation.

START WITH THE IDEA

One piece of information. More than one module needs it.

In the video's simple example, the engine computer needs coolant temperature to manage the engine. The instrument cluster needs it for the gauge. Instead of giving each module its own temperature sensor, the engine computer can share that information over a network.

  1. Temperature sensorProvides the reading
  2. Engine computerReceives it and shares the information
  3. Instrument clusterUses the shared information for the gauge

A simplified information flow from Part 1. These arrows show the idea—not connector pins, wire colors or a layout for your vehicle.

CAN—Controller Area Network—is one way vehicle modules exchange information. A vehicle can have several networks, with a gateway linking them. So when a module won't communicate, the first question is: which network are we looking at?

Follow the example in Part 1 →

CHOOSE YOUR STARTING POINT

What are you trying to understand?

New to CAN? Start with Part 1. Already tracing a fault? Study the Ascent case, then revisit the wiring or communication lesson when you need it.

New to wiring diagrams? Start with the wiring foundations →

Sources and scope

The definition of CAN follows Texas Instruments’ introduction to CAN (PDF). The diagram and cases come from GoTech’s original CAN series; source moments are linked beside each explanation. The diagram shows communication relationships, not a vehicle’s wiring or a test procedure.

Additional source moments

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