Gearbox Output Speed Sensor (Speed Of The Output Shaft)

WARNING: This page does not describe the selected car, but rather 9 other vehicles, including the 2009 Volvo S60, 2008 Volvo S60, 2007 Volvo S60, 2006 Volvo S60, and 2005 Volvo S60. However, it is still accessible from the selected car via links, so may be relevant.

Fig 1: Identifying Transmission Output Speed Sensor

Courtesy of VOLVO CARS OF NORTH AMERICA.

The gearbox output speed sensor (speed of the output shaft) is on the reverse of the gearbox housing. The sensor provides signals to the transmission control module (TCM) about the vehicle speed. The output shaft speed sensor is an active sensor and is supplied with 12 V. When the pulse wheel (wheel for shift-lock) rotates the sensor generates a pulsed current (quadratic wave) where the strength of the current depends on the position of the pulse wheel. The signals from the coils in the sensor are then affected by a magnetic resistance element, which generates a current which oscillates between 7 mA and 14 mA, and whose frequency increases with speed. The control module calculates the gearbox output speed using the signals from the sensor. The signal is compared with the signal from the gearbox input speed sensor and is used to calculate the gear ratio and is also used for diagnostics.

There are diagnostics for the gearbox output speed sensor.