Force Motor

Force Motor Circuit:

Purpose:
The force motor takes the place of the throttle valve or vacuum modulator used on past transmissions. It controls transmission line pressure.

Operation:
The force motor controls line pressure by moving a pressure regulator valve against spring pressure. The PCM/TCM varies line pressure based on engine load. Engine load is calculated from various inputs especially the TPS switch. Line pressure is actually varied by changing the amperage applied to the force motor from 0 amps at high pressure to 1.1 amps at low pressure. Current to the force motor is periodically pulsed to prevent contamination from sticking the pressure regulator valve.

Location:
The force motor is attached to the valve body.