The output speed sensor (OSS) assembly has 2 internal hall-effect type sensors, and is capable of sensing both speed and direction. The OSS mounts to the A/T rear case assembly and is connected to the control solenoid (w/body and TCM) valve assembly through a wire harness and connector. The sensor faces the hybrid direct, 2-3-4 clutch housing assembly machined teeth surface. The sensor receives 8.3-9.3 volts on the OSS supply voltage circuit from the transmission control module (TCM). 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 OSS assembly are spaced approximately 1/2 a tooth apart.

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

The vehicle speed is greater than 10 km/h (6 mph).

The TCM OSS signal and the average ABS wheel speed sensor and the drive motor signals differ by greater than 10 km/h (6 mph) for greater than 10 seconds.

P215C is a Type B DTC.

Inspect the OSS, harness, connector pins for metallic debris and output shaft machined face for damage or misalignment. Proper torque of the OSS mounting bolt is critical to proper OSS operation.

Schematic Reference

Automatic Transmission Controls Schematics

Connector End View Reference

Component Connector End Views

Electrical Information Reference

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Control Module References for scan tool information.

Special Tools

J 38522 Variable Signal Generator

Operate the vehicle at 16-32 km/h (10-20 mph) while observing the Transmission OSS and ABS wheel parameters on the scan tool. Inspect for the following mechanical conditions:

1. Disconnect the OSS connector.
2. Test for 8.3-9.3 volts between the OSS supply voltage circuit and ground.

⇒	If less than 8.3 volts, test the OSS supply voltage circuit for an open/high resistance or short to ground.

⇒	If the OSS supply voltage circuit tests normal, replace the control solenoid (w/body and TCM) valve assembly.

⇒	If greater than 9.3 volts, test the OSS supply voltage circuit for a short to voltage.

3. Using a terminal test kit, connect the J 38522 Signal Generator to the OSS signal circuit.
4. Set the J 38522 Signal Generator Signal to 5 volts, the Frequency to 120 and the Percent Duty Cycle to 50.
5. With the ignition ON, observe the Transmission OSS parameter, The Transmission OSS parameter should display between 100-400 RPM.

⇒	If the Transmission OSS is not within the specified range, test the Transmission OSS signal circuit for an open/high resistance, short to ground, or a short to voltage.

⇒	If the circuit tests normal, replace the control solenoid (w/body and TCM) valve assembly.

⇒	If the Transmission OSS is within the specified range, visually inspect the OSS and the output shaft machined surface for damage or misalignment. If OK, replace the OSS.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.