Output Shaft Speed (OSS) Sensor

OUTPUT SHAFT SPEED (OSS) SENSOR





The Output Shaft Speed (OSS) sensor is a magnetic inductive pickup that relays information relative to vehicle speed to the PCM/TCM. Vehicle speed information is used by the PCM/TCM to control shift timing, line pressure, and TCC apply and release.
The OSS sensor mounts in transaxle case near the speed sensor rotor which is pressed onto final drive assembly. An air gap of 0.27 - 1.57 mm (0.011 - 0.062 inch) is maintained between sensor and teeth on the output shaft speed sensor rotor. The sensor consists of a permanent magnet surrounded by a coil of wire. As the differential rotates, an AC signal is induced in the OSS sensor. Higher vehicle speeds induce a higher frequency and voltage measurement at sensor.
Sensor resistance should be 1500 ohms when measured at 20° C (68° F). Output voltage will vary with speed from a minimum of 0.5 volts AC at 25 RPM to 200 volts AC at 1728 RPM.