Design

Design

Control module for the steering wheel angle sensor




After initiation, with the ignition key in position II and when the steering wheel is turned 4.5 degrees in any direction, the control module for the steering wheel angle sensor continuously transmits information about the steering wheel angle position to the brake control unit to calculate the driving style of the driver. The brake control module was called ABS-control module up to and including model year 2001.
Communication between the Steering wheel angle sensor control module and the brake control module occurs on the high speed side of the Controller area network (CAN). The control module for the steering wheel angle sensor is positioned on a bracket inside the central electronic module.
The control module for the steering wheel angle sensor is supplied with power from the overload relay.

Steering wheel angle sensor




The steering wheel angle sensor is incorporated with the SRS contact reel, which in turn is installed on the steering wheel module. The steering wheel angle sensor is equipped with a disc with two code paths. Two circuits with light diodes read off a code path each. One circuit measures the steering angle up to 360 degrees and the other records how many complete turns the steering wheel has turned. Both circuits measure within +/- 700 degrees with a precision of 4.5 degrees. This information is transmitted to the control module for the Steering wheel angle sensor as digital signals.
Due to the reliance of the DSTC (Dynamic stability and traction control) on information from the steering angle sensor it is extremely important that the contact reel has been centered correctly and that only an original Volvo steering wheel is used.