Harmonic balancers – ASE practice questions (VIDEO)

Technician A and Technician B discuss electrical fundamentals. Who is correct?

Technician A argues that the 20/20 Rule captures most lab scope signals, while Technician B counters that a DSO doesn’t record signals in real time but samples and plots voltage data. Who is correct?

Technician A says the ECM’s main job is to keep emissions within certified limits. Technician B says fuel trim PIDs show corrections to fuel calculations. Who is correct?

Technician A says an empty DEF tank can cause a no-start condition. Technician B says DEF quality should be checked when SCR faults are present. Who is correct?

Proper cooling system maintenance goes beyond time and mileage, requiring technicians to evaluate coolant condition, additive depletion, and the root causes behind cooling system issues.

Technician A says other codes should be diagnosed before replacing the converter for a P0420 code. Technician B says an upstream exhaust leak can trigger the code. Who is correct?