CHAPTER 12

Diagnosing with an Oscilloscope

Learning Objectives

• 12-01 Analyze electrical component current draw.
• 12-02 Use a digital storage oscilloscope for diagnosis.
• 12-03 Analyze magnetism and induction waveforms.
• 12-04 Explain the use of transducers and inductive pickups with an oscilloscope.
• 12-05 Use current ramping and an amp clamp to aid in diagnostics.

ASE Education Foundation Tasks

See Appendix A to view the 2017 ASE Education Foundation Automobile Accreditation Task List Correlation Guide.

You Are the Automotive Technician

A 2014 Chevy Tahoe is in your bay because the vehicle has a noisy fuel pump when the vehicle is running. The customer doesn’t understand that the noise could be caused by a worn-out fuel pump. How would you explain to the service advisor that the customer needs to replace the fuel pump?

1. Tell the customer that this must be done to maintain vehicle reliability.
2. Using an amp clamp, the technician could create a waveform that shows the customer where the motor is dying.
3. Tell the customer that they can’t just wait for the fuel pump to die and then replace it.