Using an Oscilloscope (Reference)

NOTE: "INSPECTION USING AN OSCILLOSCOPE (REFERENCE)" is a general inspection for the following output devices.
- ABV solenoid valve (vacuum, vent)
- CAC bypass solenoid valve
- MAP sensor solenoid valve
- PRC solenoid valve
- EGR solenoid valve (vacuum, vent)




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




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