Steering Angle Sensor, Function

Steering Angle Sensor, Function

Operation
When the steering wheel is in the center position, the 8 blades (b) adopt a defined position with respect to the 9 light-emitting diodes (a). This center position is detected by the processor in the steering angle sensor. When the steering wheel is turned, the position of the blades changes with respect to the light-emitting diodes (light/dark). Because of the different lengths of the blades and the different intervals between them, a defined signal pattern is produced for computing the current steering wheel position. The signal patterns are used to calculate angle values which are converted into serial data for the connected control modules. The signals are detected by means of light-emitting diodes and photoelectric barriers in 2.5° increments. The signal detection is designed for a steer angle of �720° (4 turns of the steering wheel).
To ensure that the steering angle continues to be detected after "ignition OFF", the voltage supply is via terminal 30.
After an interruption to the power supply (terminal 30), the steering angle sensor must be re-initialized. This is done by turning the steering wheel from lock to lock.