On/Off solenoids can be produced in either a low pressure or high pressure default (power off) condition. Typically, on/off solenoids enable gear changes by actuating a multiplexing valve which in turn directs hydraulic pressure to the proper clutch.

PWM - High-flow and low-flow pulse width modulated solenoids provide pressure output proportionally or inversely proportionally to input voltage pulse width. The low-flow solenoid provides signal level control, typically for torque converter control. The high-flow solenoid is used in line pressure or direct clutch control applications.