A technician is performing a diagnostic check on a vehicle's ABS system due to an intermittent warning light. During a road test, the technician notices that the ABS light illuminates only when turning sharply to the left. No DTCs are stored in the ABS module. Which of the following is the MOST likely cause?
- AA misaligned steering angle sensor.
- BA faulty ABS control module.
- CA low brake fluid level in the master cylinder.
- DA damaged wheel speed sensor wiring harness on the right front wheel.
Show answer & explanationAnswer & explanation
Correct answer: D. A damaged wheel speed sensor wiring harness on the right front wheel.
An intermittent ABS light that illuminates specifically during a sharp turn suggests a wiring or sensor issue that is affected by movement. Turning sharply to the left would put stress on components on the right side of the vehicle (as the body leans and suspension articulates), potentially causing a damaged wheel speed sensor wire (e.g., chafed, stretched, or loose connection) on the right front wheel to briefly lose signal, triggering the light without necessarily setting a hard DTC.
Why the other options are wrong
- A. A misaligned steering angle sensor would typically affect stability control systems (TCS/ESC) more directly and would likely set a steering angle sensor-specific DTC, rather than an intermittent ABS light during a turn, especially without a stored code.
- B. A faulty ABS control module would likely cause more consistent or random issues, or set a specific module fault code, not just during a specific turn.
- C. A low brake fluid level would typically trigger the general brake warning light, not specifically the ABS light, and would not be tied to turning maneuvers.
Intermittent ABS Faults
Intermittent ABS warning lights tied to specific maneuvers (like turning) often indicate a wiring harness or sensor connection issue affected by suspension or steering movement.
- Movement-related fault
- Wiring/connector integrity
- Often no stored DTC initially
Memory trick: Turn the wheel, light appears? A wire's frayed, calm your fears!