C0305

Step 1: Perform visual inspection of both front wheel speed sensors, connectors, and wiring for physical damage, corrosion, contamination from debris or grease, and proper connector engagement. Check for damaged CV boots that may have thrown grease onto sensor.

Step 2: Using a multimeter, measure resistance across the wheel speed sensor terminals (typically 800-1400 ohms for passive sensors, or verify 5V reference and ground for active sensors). Compare readings between left and right sensors to identify discrepancies.

Step 3: Inspect the ABS tone ring/reluctor ring for missing teeth, cracks, rust buildup, or metallic debris. Rotate the wheel and measure air gap between sensor tip and tone ring with feeler gauge (typical specification 0.020-0.050 inches). Check for excessive wheel bearing play by grasping tire at 12 and 6 o'clock positions.

Step 4: Use scan tool to monitor live wheel speed sensor data while rotating each front wheel by hand or during a slow test drive. Identify which sensor shows erratic, intermittent, or no signal output compared to the other front sensor.

Step 5: Perform voltage drop test on sensor ground circuit and check continuity from sensor connector to ABS module connector to identify wiring faults or poor grounds. Inspect wiring routing near suspension components for chafing or pinch points.

Step 6: After repair, clear codes, perform test drive including ABS activation (safe environment), and verify sensor signals are stable and consistent at all speeds using scan tool live data.