Shift solenoid S1 and S2
WARNING: This page does not describe the selected car, but rather 8 other vehicles, including the 2006 Volvo S80, 2005 Volvo S80, 2004 Volvo S80, 2003 Volvo S80, and 2002 Volvo S80. However, it is still accessible from the selected car via links, so may be relevant.
The shift solenoids S1 and S2 are positioned in the valve housing, which is mounted behind the side cover of the transmission. The shift solenoids (on/off type), consist of an electrical coil which controls a hydraulic valve. The solenoids are supplied with 12 V via the transmission control module (TCM) and grounded at the ground terminal. The shift solenoids control shifting and the transmission control module (TCM) determines which gear is to be used by activating them in different patterns.
There is a diagnostic for the electrical function of the shift solenoids. There is also a diagnostic for the hydraulic circuit, but not for the hydraulic function of the solenoids.