Switch Unit: Notes
WARNING: This page is about a different car, the 2007 Saab 9-5. However, it is still accessible from the selected car via links, so may be relevant.
The switch unit is located on the outside of the driver's seat. It comprises a number of switches that are supplied with B+ from the control module. When a switch is closed, the B+ supply is returned to the respective switch input on the control module. The voltage then changes from 0V to B+.
When a valid switch setting or memory button is detected, the control module performs the corresponding function, i.e. controls the motors for manual adjustment and memory setting or stores the seat settings when programming.