Volkswagen automatic transmission input shaft speed sensor
Function:
* Monitoring the rotation speed of the input shaft of an automatic transmission (AT).
* Providing this information to the transmission’s electronic control unit (ECU).
Location:
The input shaft speed sensor is usually located on the automatic transmission housing next to the input shaft.
Sensor type:
*Hall sensor
* Inductive sensor
Working principle:
*Hall sensor: When the input shaft teeth rotate in front of the sensor, the magnetic field of the teeth changes. This change in magnetic field induces an output signal in the Hall sensor.
* Inductive Sensor: The sensor contains a coil that creates a magnetic field. When the input shaft teeth rotate in front of the sensor, the teeth change the magnetic field, which causes voltage to be generated in the coil.
Output signal:
The output signal of the sensor is an analog voltage or pulse signal, which is proportional to the rotation speed of the automatic transmission input shaft.
Diagnostics:
*Faulty Sensor: A faulty sensor can cause the input shaft speed to be incorrectly detected, which can affect transmission performance and cause trouble codes.
*Damaged Wiring: Damaged wiring can cause communication between the sensor and the ECU to be interrupted, which can also cause transmission problems.
Possible causes of the malfunction:
* Sensor wear due to friction or corrosion
* Damage to the sensor housing
* Problems with wiring or connections
* Magnetic interference from other components
Consequences of the malfunction:
* Incorrect gear shifting
*Transmission slippage
*Poor fuel economy
*Transmission related fault codes
* Deterioration in vehicle handling