Steering wheel angle sensor
WARNING: This page is about a different car, the 2009 Saab 9-3. However, it is still accessible from the selected car via links, so may be relevant.
The steering wheel angle sensor is fitted to a snap mounting inside the CIM and is directly connected to the circuit board with a 4-pin connector. The steering wheel angle sensor reads the steering wheel angle with a toothed wheel which meshes with the toothed inner sleeve of the contact roller.
The sensor contains 4 Hall sensors and a microprocessor. The CIM continuously sends steering wheel angle information on the bus. 0° corresponds to a straight ahead position; a value which increases when the steering wheel is turned to the left. The sensor must be calibrated after changing the straight ahead position of the steering wheel or steering wheel replacement. Sensor fault requires CIM replacement.