Technician Handbook ! 673 Electronic & Computer Controlled Systems Pulse Width One component can send a signal to another with a voltage pulse. In this case, it is the duration of the pulse, or pulse width , that conveys information. In late-model vehicles for example, tapping the horn switch quickly sends a voltage pulse over the BEAN network to the Body ECU. • A 13 ms. pulse causes the horn to sound for 106 ms. • A 30 ms. pulse also causes the horn to sound for 106.ms. • A 100 ms. pulse causes the horn to sound for 173 ms. • An 8 ms. pulse does not cause the horn to sound at all.
In this example, the ECU sounds the horn for a pre-calculated length of time based on the width of the pulse (duration of the voltage signal) from the horn switch. Technical Training 27