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Output Shaft Rpm Sensor, Component Description - GF27.19-D-1113HAG

TRANSMISSION 722.9 in MODEL 906 

Electric controller unit (Y3/8) viewed from left 

G10885775Courtesy of MERCEDES-BENZ USA

Location 

The output speed sensor is positioned on the electric controller unit.

Task 

The output speed sensor detects the transmission output speed at the park pawl gear for the fully integrated transmission control. Together with the information from the turbine wheel RPM sensor and from the internal transmission RPM sensor this is processed as input signals by the control unit (Y3/8n4). This contributes to shortening the reaction time during shift operations.

Design 

The output speed sensor is firmly fixed to the electric controller unit and cannot be replaced individually.

Function 

The transmission output speed is recorded using a pulse ring and a Hall difference sensor. This increases the measuring accuracy. 2 Hall generators and a bar magnet are integrated into the output speed sensor. Magnetic field changes occur due to the rotary motion of the pulse ring. As a result an induction difference arises between the two Hall elements of the Hall generators which changes its polarity due to the rotary motion.

This polarity change is converted into an RPM signal by the electronic analysis system and evaluated by the control unit.