Pressure Control Valve

The piston in the shift travel cylinder must be moved in both directions (in/out) by pressure. Two pressure control valves are required to achieve this movement.

With no current applied to the valves they are in the open position allowing connection of the cylinder chamber and the expansion tank. Applying current to one of the solenoids will cause hydraulic fluid to flow against the cylinder piston pushing it in one direction. Fluid from the other side of the piston will be forced through the second control valve into the expansion tank.

Fig 1: Pressure Control Valve Schematic

Courtesy of BMW OF NORTH AMERICA, INC.

Fig 2: SMG II Schematic

Courtesy of BMW OF NORTH AMERICA, INC.

Fig 3: Index Reference Chart

Courtesy of BMW OF NORTH AMERICA, INC.