GF42.45-P-4600-02C

Steering angle sensor, function

Models 211, 215, 220, 230, 240

Optical sensor featuring 6 light-emtting diodes (a) for measurements using light beams. The steering-angle sensor consists of 2 microprocessors that join with a crescent-shaped signal monitoring rack to form a single unit. The signal monitor comprises 6 equadistant light-emitting diodes (a) arranged to monitor an angle extending over 72°. They form a light beam path which is traversed by 5 groups of shutters of three different lengths (b). The shutters (a) are installed within the steering-angle sensor (N49), which is installed at a fixed location on the steering column jacket (N80). The shutters (b) are located in the moving upper portion of the spiral contact coils (A45), and both components must be joined to form the complete operational unit that makes up the optical steering-angle sensor (N49). A45 Clock spring contact N49 Steering angle sensor a Photoelectric barrier LED b Blade
		P42.45-2134-12

When the steering wheel is in the center position, the 15 blades (b) adopt a defined position with respect to the 6 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 registered by the

light-emitting diodes and light beams in 2° intervals. 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.