DTC C1202-02: Wheel Speed Sensor Front-LH Invalid/No Signal: General Description

The wheel speed sensor is the essential component the ABS ECU (ESP/ESC) because ESP (ESC) calculates vehicle speed and determines whether wheel lock occurs based on data from the sensor.

For example, front-wheel vehicles use speed of a faster rear wheel as a reference when determining vehicle speed, and, if the vehicle detects difference in speed between front and rear wheel, ABS control sets in.

Wheel speed sensor is active hall-sensor type.