CAN Bus Communications Decoded: Making a Physical Connection
Making a Physical Connection
01.12
00:00 | - The second step of the CAN bus reverse engineering process is making a physical connection to the bus wires. |
00:06 | We've talked about this in a lot of detail in the tapping into an existing CAN bus module in the Practical Discussion section of the course and this is the point where you're going to put those skills to use. |
00:17 | Using either factory documentation or probing with an oscilloscope, find the bus wires at a device connector if possible or within an exposed section of the wiring harness. |
00:28 | The reason we recommend to do this at a device connector is that it's usually preferrable to back probe a connector, as opposed to piercing the wire insulation in the middle of a harness section. |
00:39 | It's important to be sure that the physical connection you make is reliable and as robust as possible. |
00:45 | Don't by shy about using electrical tape or cable ties to ensure your probes stay in place as they can be easily knocked while working in the interior and the connection to the bus will be lost. |
00:56 | If you're using an oscilloscope to probe and find the bus wires, now is the time to determine the bus speed by measuring the bit length of a single data bit. |
01:05 | This will let you configure your CAN analyser tool correctly on the first try. |