Transmission pressure control solenoids are intended to control the fluid pressure for proper operation in an automatic transmission.
These devices send the PCM an electronic signal based on their internal pressure. It is important to mention that for the automatic transmission to work properly, the belts and clutches that control it must change gears when the fluid pressure is at the right place at the right time. For this reason, to direct the fluid at the right pressure to the different hydraulic circuits, the PCM controls the pressure solenoids to change the transmission ratio at the right time.
When the diagnostic code P0746 OBDII is stored, it is because the pressure control solenoid “A” is not working properly or is stuck in the off position.