Solenoid Relay Valve
WARNING: This page is about a different car, the 2003 Saturn Vue. However, it is still accessible from the selected car via links, so may be relevant.
B5 control 1 (37) fluid pressure passes through the solenoid relay valve into the B5 control 2 (38) fluid circuit. B5 control 2 (38) fluid pressure is then routed through the U1 shift valve and on to the M1 shift valve.