Operation

OPERATION

The optical steering angle sensor is a digital sensor with nine light-emitting diodes, and eight barrier blades. The LED's within the sensor are used in conjunction with the barrier blades to detect the rotation and position of the steering wheel.

With the steering wheel in the center position, the eight blades assume a defined position in relation to the nine LED's. This center position is recorded by the processor in the steering angle sensor. When the steering wheel is turned, the position of the blades change in relation to the LED's (light/dark). A distinct signal pattern for calculating the steering wheel angle is produced from the different length blades and the spacing of the blades. Using the signal patterns, angle values are calculated and converted into serial information for the module.

The recording of a signal by LED's and light-beam barriers is registered on a 2.50 degree variation and is designed for 720 degrees of total steering angle (4 steering wheel revolutions). The steering angle sensor has continuous battery voltage supplied by the underhood accessory fuse block. The steering angle sensor must be reinitialized after voltage has been interrupted.