Steering Wheel Angle Speed Sensor: Operation
The split of the steering angle sensor detects a steering angle of the steering wheel by a ON/OFF pulse caused by whether or not the LED lights go through the hole of the split, rotating as the steering wheel revolves. There are three LEDs, two (ST1, ST2) for detecting a steering direction, and the other for the neutral position.
The HECU calculates the steering angle by the pulse from the steering angle sensor.