Oscilloscope Patterns and Waveforms

Typical Oscilloscope Test On A Solenoid Valve:

Purpose
By using an oscilloscope, inspection such as a stuck solenoid valve is made possible without actually removing parts.

When Normal:

(1) When normal
Counter electromotive voltage A, generated when the three-way solenoid valve or the fuel injector is turned off from on, shows irregular convergence because induced electromotive voltage B, generated by the plunger return operation, is added to it.

When Plunger Stuck:

(2) When plunger stuck
When the plunger is stuck, pulse convergence is smooth because no induced electromotive voltage B is generated.