SRT-4 L4-2.4L Turbo VIN S (2004)
Part 2 Of 2
The rear wheel speed sensors are mounted through the disc brake adapter (Fig. 8) (Fig. 9). The rear tone wheels are mounted to and rotate with the
hub and bearing assemblies.
The WSS air gaps are not adjustable. The initial factory WSS air gap specification can be found in SPECIFICATIONS. Each WSS is serviced
individually. The tone wheels are serviced as an assembly with the hub and bearing assemblies.
OPERATION
The CAB sends 12 volts to power an Integrated Circuit (IC) in the sensor. The IC supplies a constant 7 mA power supply to the CAB. The
relationship of the tooth on the tone wheel to the permanent magnet in the sensor, signals the IC to enable a second 7 mA power supply. The output of
the sensor, sent to the CAB, is a DC voltage signal with changing voltage and current levels. The ground for the IC and the current sense circuit is
provided by the CAB.
When a valley of the tone wheel is aligned with the sensor, the voltage signal is approximately 0.8 volts and a constant 7 mA current is sent to the
CAB. As the tone wheel rotates, the tooth shifts the magnetic field and the IC enables a second 7 mA current source. The CAB senses a voltage signal
of approximately 1.6 volts and 14 mA. The CAB measures the amperage of the digital signal for each wheel. The resulting signal is interpreted by the
ABS CAB as the wheel speed.
