Missing data packages on CAN-LOW. Designed by N. Bertelt und H. Cinar

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This Video shows you the CAN-bus signals of a single wire capable CAN-bus Comfort. In our example, we have a Golf V from Volkswagen built in 2005. We used a digital oscilloscope, to measure the signals you can see from our screenshot. On the screenshot you can see channel A which is marked yellow and channel B marked in a purple colour. On the X-axis of our graph we count the time, which in our case is adjusted at 500µs (microseconds). With a total of ten divisions we have a period of 5ms (milliseconds). With our oscilloscope, we can’t adjust the time for both channels separately, but the Y-axis is adjustable for both channels individual. The Y-axis shows the current which in our example is adjusted at 2V per division.
The trigger which is used to get a still image, is configured as automatic. As a car-mechatronic this always makes sense for us. We literally can see one data package which is tagged in the section of 1 to 2. In the bottom left corner of the picture we can see how much time the transfer of the data package took. It took a total of 1150µs. The signals have a current level of 4,1V which are also tagged in the sections of A or B. In the shown shot you can see that the CAN-low package is not complete. This image is caused if a control unit is damaged, or also if the wires for data transfer are partly broken or oxidized. The broken control unit can only be found if we start removing every control unit one by one. If the incorrect data package disappears after we removed another control unit, we know that the last control unit we worked on creates the failure in our system. If the failure does not disappear, we have to check the wire connection.

Видео Missing data packages on CAN-LOW. Designed by N. Bertelt und H. Cinar канала Kraftfahrzeugtechnik pur