900 SE Convertible V6-2498cc 2.5L DOHC (1995)
Transmission Speed Sensor: Description and Operation
Output Shaft Speed Sensor
OUTPUT SHAFT SPEED SENSOR
The Output Shaft Speed (OSS) sensor is fitted in the transmission housing. It gives the Transmission Control Module (TCM) information about
the outgoing rpm of the transmission. The OSS sensor is of the electro-magnetic (inductive) type and measures the outgoing rpm by being affected
by a toothed pulse wheel (the parking lock's ring gear). The sensor's signal voltage, a sine voltage, increases with the speed of the car. At 30 km/h
it is about 1.1 V and 110Hz measured between pins 30 and 31 on the sensor.
Pin 30 is signal voltage and pin 31 is signal ground. The resistance between pins 3 and 2 on the sensor connector is 300 - 600 ohms.
The TCM uses the speed signal to check the points of time of the gear shiftings.
