When the clock frequency is increased, the bus load is too high, a scene similar to “traffic jam” appears, and the signal transmission rate decreases. At the same time, too long wiring harness will also cause signal delay. The amplitude change refers to the difference between the maximum and minimum values of the voltage or current and the set value after the current or voltage signal is affected by the external electromagnetic field. When the coupling effect of the external signal and the internal signal of the wiring harness is inconsistent, the result of the differential signal will also be inconsistent with the preset value, and the amplitude will rise or fall. The signal jump indicates that the slope of the rising or falling edge of the signal is abnormal, and the rising and falling edges are related to the clock frequency of the signal. When the clock frequency of the signal is high, the current changes rapidly, the intensity of the electromagnetic wave released to the outside is large, and the coupled electromagnetic field also increases, which has a stronger weakening effect on the original signal and causes the signal to jump. Timing is an important parameter of a signal, and signals with different timings represent different information. After the wiring harness receives electromagnetic interference, local information lags behind or the amplitude changes abnormally, which leads to the disorder of the timing of the signal and the transmission of wrong information.