Wheel Speed Sensor

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📖 YOUCANIC Automotive Glossary

Wheel speed sensors measure the rotational speed of each individual wheel, providing critical data for ABS (detecting wheel lockup), traction control (detecting wheel spin), ESC (detecting vehicle dynamics), speedometer, and transmission shift strategy. Most modern vehicles use active Hall-effect sensors that produce a digital signal at all speeds (including very slow), while older vehicles may use passive magnetic sensors generating AC signals. Each sensor reads a toothed tone ring (encoder ring) mounted on the wheel hub, CV axle, or brake rotor.

Wheel speed sensor failures are the most common ABS fault. DTCs: C0035-C0050 (individual wheel sensor codes). Symptoms: ABS/traction/ESC warning lights, speedometer fluctuations, and erratic cruise control. Common causes: damaged sensor wiring (exposed to road debris and water), corroded sensor connector, cracked tone ring, and metallic debris on the sensor tip. Live data comparison on the YOUCANIC UCAN-II showing all four wheel speeds during driving quickly reveals which sensor reads incorrectly.

Synonyms:
WSS, ABS Sensor, Speed Sensor
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