Subaru Automatic Transmission Selector Position Sensor
Function:
The automatic transmission selector position sensor (automatic transmission) determines the position of the gear shift lever and transmits this information to the electronic control unit (ECU). This information is used by the ECU to control proper gear shifting, engine starting, and other transmission-related functions.
Location:
The automatic transmission selector position sensor is usually located on the base of the gear selector or in the gear selector itself.
Working principle:
The automatic transmission selector position sensor usually consists of a resistive wire or several switches that change the resistance of the circuit depending on the position of the gearshift lever. When the shift lever is moved, the circuit resistance changes and is read by the ECU. The ECU then interprets the resistance and determines the position of the shift lever.
Malfunctions:
A faulty automatic transmission selector position sensor can lead to the following problems:
* Incorrect gear shifting
* Difficulty starting the engine
* Inability to change gear from parking mode
*Check Engine or Transmission Error Code
Causes of malfunction:
* Wear or mechanical damage to the sensor
* Faulty wiring or connectors
* Contamination or corrosion of the sensor or its components
Diagnostics and repair:
Diagnosis of a faulty automatic transmission selector position sensor may include:
* Reading fault codes
*Physical inspection of sensor and wiring
* Sensor circuit resistance testing
Repairing a faulty automatic transmission selector position sensor usually includes replacing it with a new one.