In addition to other measured variables, the ABS/DSC control unit also requires the steering angle to calculate the transverse dynamics.
The steering angle is recorded by a separate steering angle sensor. This steering angle sensor is designed as a 360 degree potentiometer. The measuring range is 2 x 180 degrees.
To ensure satisfactory measurement results, a double steering angle sensor is installed. The two slider contacts are offset by 90 degrees with respect to each other.
The steering angle sensor can, for example, be installed such that when the wheels are in the straight ahead position a very low voltage is applied at the slider.
If the steering wheel is now turned to the right or left, the voltage picked off from the slider increases in linear progression until the maximum value of approx. 5 Volt is reached at an angle of 180 degrees. When the steering wheel is turned further in the same direction, the voltage at the slider decreases in linear progression until the minimum value of approx. 0.5 V is reached.
The delta voltage formed in this way by the potentiometer is evaluated by the control unit and converted into steering angle.
The positive and negative supply of both potentiometers takes place via the ABS/DSC control unit. The supply voltage is 5 Volt.
Note
When replacing the steering angle sensor, it is not necessary to adjust the position of the sensor with respect to the steering wheel. After installation, however, steering angle adjustment with the diagnosis and information system must be carried out (Section "Service Functions", Subsection "Steering Angle Adjustment").