ASE G1 Auto Maintenance and Light RepairBrakesEasy
A technician is performing a pre-purchase inspection. The vehicle has an ABS system, and the ABS warning light illuminates briefly during startup self-test and then turns off. What does this behavior indicate?
- AThe ABS light bulb is faulty.
- BA fault exists in the ABS system that cleared itself.
- CThe ABS module is completely inoperative.
- DThe ABS system is functioning normally.
Show answer & explanationAnswer & explanation
Correct answer: D. The ABS system is functioning normally.
Most modern vehicle warning lights, including the ABS light, are designed to illuminate briefly during startup as part of a system self-test. If the light then turns off, it indicates that the system passed its self-check and is functioning normally.
Why the other options are wrong
- A. If the bulb were faulty, it would either never illuminate or remain illuminated, not perform a normal self-test cycle.
- B. If a fault existed, the light would remain illuminated after the self-test, not turn off.
- C. If the ABS module were inoperative, the light would likely remain illuminated, or not illuminate at all, not perform a normal self-test and then turn off.
ABS Light Self-Test
A brief illumination of the ABS warning light during vehicle startup, indicating that the ABS control module is performing a diagnostic check of its components.
- Normal behavior if the light turns off afterward.
- If the light stays on, it indicates a fault in the ABS system.
- If the light never illuminates, it could indicate a bulb or circuit fault.
Memory trick: A quick flash means all systems are a-OK!