The automatic transmission lever position switch is an electrical device that determines the position of the gear selector in an automatic transmission (AT).
Target:
* Transmits information about the selected gear position to the transmission control unit (TCU) or engine control module (ECM).
* Prevent unauthorized gear changes while the engine is running.
Design:
The switch is usually installed on the automatic transmission housing and consists of:
* A set of contacts corresponding to different gear selection positions.
* Selector lever connected to contacts.
Working principle:
When the gear selector lever moves, the shift lever also moves, closing the corresponding contacts. This sends an electrical signal to the TCU or ECM, which recognizes the selected gear position.
Types of automatic transmission lever position switches:
* Mechanical: Have physical contacts that close and open when the selector lever is moved.
* Magnetic: Use magnets to close and open reed contacts.
* Non-contact: Detect the position of the selector lever using Hall sensors or optical sensors.
Malfunctions:
Malfunctions of the automatic transmission lever position switch can lead to:
* Inability to change gears.
* Incorrect indications of the selected gear on the dashboard.
* Prohibition of gear shifting when the engine is running.
* The appearance of fault codes on the scanner.
Automatic transmission shifter position switch repair usually involves replacing the faulty component or adjusting the selector lever.