Operation Manual

FEATURES
1-16
EAS59C2102
ABS COMPONENT FUNCTIONS
Wheel sensors and wheel sensor rotors
Wheel sensors “1” detect the wheel rotation speed and transmit the wheel rotation signal to the ABS
ECU.
Each wheel sensor contains a Hall IC. The wheel sensors are installed in the sensor housing for
each wheel.
Sensor rotors “2” are installed on the inner side of the front and rear wheel hubs and rotate with the
wheels.
The front sensor rotor has 80 magnetic poles (40 pairs) and the rear sensor rotor has 92 magnetic
poles (46 pairs). They are installed close to the wheel sensors. As the sensor rotor rotates, the Hall
element in the Hall IC installed in the wheel sensor generates pulses. The pulse frequency, which is
proportional to the magnetic flux density, is converted into a wave in the Hall IC so that it can be out-
put.
The ABS ECU calculates the wheel rotation speed by detecting the pulse frequency.
3. At low speed
4. At high speed
5. Wheel sensor
6. Wheel sensor rotor
7. Voltage
8. Time