Output Speed Sensor (OSS)
The output speed sensor assembly has 2 internal hall-effect type sensors, and is capable of sensing both speed and direction. The output speed sensor mounts to the A/Trans case assembly and is connected to the hybrid/EV powertrain control module 1 through Automatic Transmission Wiring Harness - Control Solenoid Valve. The sensor faces the front differential drive pinion (w/transfer gear) gear assembly machined teeth surface. The sensor receives 8.3 - 9.3 volts on the OSS supply voltage circuit from the hybrid/EV powertrain control module 1. As the output shaft rotates, the sensor produces a signal frequency based on the machined surface of the output shaft.
The two sensor elements in the output speed sensor assembly 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 serial data circuits to the ECM. The ECM and hybrid/EV powertrain control module 1, compare the output speed sensor signal with the anti-lock brake system wheel speed sensor signal. The hybrid/EV powertrain control module 1 also compares the output shaft direction with the drive motor 1 and drive motor 2 direction.