ASE G1 Auto Maintenance and Light RepairElectrical/Electronic SystemsMedium
A vehicle's dashboard warning light for the anti-lock braking system (ABS) illuminates intermittently. A technician connects a scan tool and retrieves Diagnostic Trouble Code (DTC) C0035, indicating a 'Left Front Wheel Speed Sensor Circuit Malfunction'. Which of the following is the MOST likely cause?
- AA worn brake pad on the left front wheel
- BA faulty ABS hydraulic control unit (HCU)
- CLow brake fluid level in the master cylinder
- DA damaged left front wheel speed sensor wiring harness
Show answer & explanationAnswer & explanation
Correct answer: D. A damaged left front wheel speed sensor wiring harness
DTC C0035 specifically points to a circuit malfunction in the left front wheel speed sensor. This indicates an issue with the sensor itself or its wiring, rather than the hydraulic unit, fluid level, or brake pads.
Why the other options are wrong
- A. Worn brake pads do not directly cause a wheel speed sensor circuit malfunction; they would affect braking performance and potentially trigger a brake wear indicator if equipped.
- B. A faulty HCU would likely trigger different DTCs or affect multiple wheels, not just a single wheel speed sensor circuit.
- C. Low brake fluid level typically triggers a 'BRAKE' warning light, not an ABS specific DTC C0035.
DTC C0035
DTC C0035 indicates a circuit malfunction in the left front wheel speed sensor, signifying an issue with the sensor or its wiring.
- Specific to left front wheel speed sensor circuit.
- Implies electrical issue (sensor or wiring).
- Requires diagnostic steps beyond simple visual inspection.
Memory trick: Always Be Sure to Scan for Specifics.