Automatic Transaxle Output Speed Sensor (A/T OSS)
WARNING: This page is about a different car, the 2005 Suzuki Reno and 2005 Suzuki Forenza. However, it is still accessible from the selected car via links, so may be relevant.
The vehicle A/T OSS is a magnetic inductive pickup that relays information relative to vehicle speed to the TCM. Vehicle speed information is used by the TCM to control shift timing, line pressure, and TCC (lock-up clutch) apply and release.
The output speed sensor mounts in the case at the speed sensor rotor, which is pressed onto the spur gear. An air gap of 0.1-1.3 mm (0.004-0.05 in) is maintained between the sensor and the teeth on the spur gear teeth. The sensor consists of a permanent magnet surrounded by a coil of wire.
As the differential rotates, an AC signal is generated by the output speed sensor (OSS).