Fluid Pressure Directed in Preparation for a Shift to Third Gear
WARNING: This page is about a different car, the 2012 GMC Yukon, 2012 Chevrolet Tahoe, and 2012 Cadillac Escalade. However, it is still accessible from the selected car via links, so may be relevant.
Shift Solenoid Valve - Mode B
HD 234 clutch/B cooling feed fluid is routed to the shift solenoid valve - mode B where it is blocked by the valve in preparation for an upshift to third gear.