Michigan State Brakes Certification Practice Exam 2026 – All-in-One Study Guide for Exam Success!

Using AC volts to test an ABS wheel speed signal with a digital multimeter is appropriate because the wheel speed sensors in an anti-lock braking system (ABS) typically generate an AC voltage signal. This signal is produced by the movement of the wheel through a magnetic field created by the sensor. The rotation induces a voltage proportional to the wheel speed, and this voltage fluctuates in an alternating manner, hence the need to use the AC voltage setting on the multimeter to measure it accurately.

In contrast, using DC volts would not capture the nature of the alternating signal produced by the sensor. Resistance measurement is irrelevant in this case as you are not trying to determine the resistance of the circuit but rather to measure a dynamic signal that indicates the speed of the wheel. A continuous tone setting, used for continuity checks or to sense voltage presence in circuits, does not provide the detailed information required to assess the performance of the ABS wheel speed sensor and would not give a measurable output indicative of wheel speed.