km time does not work

Hello friends, my km hour is 1 month, defective masters said that it could be caused by km sensor or a piece behind the clock. Sensor replacement has been done today, but no results, I would be glad if you can solve the problem on the screen. I'm an electronic technician, I would appreciate if you write the method I want to handle this myself.

If possible, plug in another dial and try. Testing in this way will be the shortest way to detect the malfunction.

Or if there is a trip computer and there is no problem measuring the average speed, the problem is most likely in the dial.

There is no trip computer, we changed the dial after the sensor replacement. but I do not want to take this work to the mechanic. I looked, but it was not so detailed.