Steering Wheel Angle Sensor

Steering wheel sensor is located in steering column. Steering wheel sensor consists of a disc with uniform slits, positioned between an LED, a fixed slit and a photo transistor. As steering wheel is turned, disc rotates and blocks light from LED. Light that passes through disc and fixed slit to photo transistor is converted into a 5 volt output signal. Output signal has an "A" phase (4 degree, single cycle) and a "B" phase (one degree, 1/4 cycle) output. TCS control unit uses steering angle sensor signals to detect steering wheel turning angle and direction of turn.