Circuit/System Description

WARNING: This page is about a different variant/trim than selected.

The transmission output shaft speed sensor has 2 internal hall-effect type sensors and is capable of sensing both speed and direction. The transmission output shaft speed sensor mounts to the A/Trans case assembly and is connected to the hybrid/EV powertrain control module 1 assembly through a wire harness and connector. The sensor faces the drive sprocket machined teeth surface. The sensor receives 5 V on the OSS supply voltage circuit from the hybrid/EV powertrain control module 1. As the drive sprocket rotates, the sensor produces a signal frequency based on the machined surface of the drive sprocket.

The two sensor elements in the transmission output shaft speed sensor are spaced approximately 1/2 a tooth apart.

When the vehicle is moving in a forward direction, sensor A detects a particular tooth before sensor B.
When the vehicle is moving in a reverse direction, sensor B detects a particular tooth before sensor A.

The electronics in the sensor combine the two signals and send a signal with a different pulse width. This signal is interpreted by the hybrid/EV powertrain control module 1 for speed and direction and is transmitted through the GMLAN circuits to the ECM. The ECM and hybrid/EV powertrain control module 1, compare the OSS signal with hybrid motor speed/direction and the ABS wheel speed sensor signal.