Automatic transmission selector solenoid valve
The automatic transmission selector solenoid valve is an electromechanical component that controls gear shifting in an automatic transmission. It converts electrical signals from the transmission control module (TCM) into mechanical movement that moves the selector valve to change fluid flows in the transmission.
Operating principle
The selector solenoid valve consists of the following components:
* Electromagnetic Coil: An electromagnet generates a magnetic field when an electric current is applied to it.
* Armature: An armature is a movable metal component that is attracted to an electromagnet when current is applied.
* Vacuum Valve: A vacuum valve is opened and closed by an armature, which allows or blocks the passage of fluid through the valve.
When the TCM sends an electrical signal to the solenoid coil, the magnetic field attracts the armature, opening the vacuum valve. This allows fluid to flow through the valve into the corresponding passage in the transmission, causing the gear to change. When the electrical signal is turned off, the spring returns the armature to its rest position, closing the vacuum valve and interrupting the flow of fluid.
Functions
The selector solenoid valve performs the following functions:
* Shifts gears in response to signals from the TCM.
* Regulates fluid pressure in various transmission channels.
* Provides fast and smooth gear changes.
* Prevents multiple gears from being engaged at the same time.
Types
There are several types of selector solenoid valves that are used in various automatic transmission models:
* Valves 3-2: Control the gear shift from 3 to 2.
* Valves 4-3: Control gear changes from 4 to 3 and higher.
* Valves 1-2: Control the gear shift from 1 to 2.
* Downshift valves: Control downshifts.
Malfunctions
A faulty selector solenoid valve can lead to shifting problems such as:
* Slipping or delay when shifting gears
* Switch to emergency mode
* No shifting to certain gears
* Incorrect gear shifting
Replacement
In the event of a malfunction, the selector solenoid valve is usually replaced with a new one. Replacement requires specialized knowledge and equipment and should be performed by a qualified mechanic.