Mercedes automatic transmission speed sensor input
The automatic transmission input speed sensor is an electronic component that is used to determine the speed of rotation of the automatic transmission input shaft. This data is used by the transmission control module (TCM) to adjust shift pressure and timing.
Location of the Mercedes automatic transmission input speed sensor
The location of the sensor may vary depending on the Mercedes model, but it is usually located in the automatic transmission bell housing, close to the torque converter.
Operating principle of the automatic transmission input speed sensor
The speed sensor is usually a non-contact magnetic sensor that works as follows:
1. Inside the sensor there is a permanent magnet that creates a magnetic field.
2. When the automatic transmission input shaft rotates, a special gear passes next to the sensor, changing the magnetic field.
3. This change in magnetic field generates an electrical signal that is proportional to the speed of rotation of the input shaft.
Symptoms of a faulty automatic transmission input speed sensor
A faulty or damaged automatic transmission speed sensor can lead to the following problems:
*Rough gear shifting
* Delay when shifting gears
* Incorrect speedometer readings
* ‘Limp’ mode (gearbox gets stuck in one gear)
Replacing the automatic transmission speed sensor
Replacing an automatic transmission speed sensor is usually a relatively simple procedure that can be performed by most auto repair shops. Here are the general steps that may be involved in the replacement process:
1. Raise the car on a lift or use stands.
2. Disconnect the electrical connector of the speed sensor.
3. Unscrew the sensor fixing bolts.
4. Remove the old sensor and install the new one.
5. Tighten the sensor fixing bolts.
6. Connect the electrical connector.
7. Lower the car and check the operation of the automatic transmission.
Always use genuine or reputable parts to ensure proper transmission operation.