2010 Cadillac Truck Escalade/ESV RWD V8-6.2L Page 1733

2010 Cadillac Truck Escalade/ESV RWD V8-6.2L Page 1733

Circuit/System Description

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/T rear case assembly and is connected to the control solenoid 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. 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 transmission

control module for speed and direction and is transmitted through the serial data circuits to the engine control module (ECM) and the hybrid

powertrain control module. The ECM, hybrid powertrain control module, and transmission control module compare the OSS signal with the anti

lock brake system wheel speed sensor signal. The hybrid powertrain control module also compares the output shaft direction with the drive motor 1

and drive motor 2 direction.

Conditions for Running the DTC

* The OSS speed parameter is less than 50 RPM.

* The drive motor estimated output speed is greater than 50 RPM.

Conditions for Setting the DTC

The hybrid powertrain control module or the transmission control module detects an incorrect OSS direction.

Action Taken When the DTC Sets

Hybrid Powertrain Control Module

The hybrid powertrain control module calculates OSS direction based on drive motor 1 and drive motor 2 direction.

Transmission Control Module

* The transmission control module freezes transmission adaptive functions.

* The transmission control module turns OFF all solenoids.

Conditions for Clearing the DTC

Hybrid Powertrain Control Module

P077B is a Type A DTC.

Transmission Control Module

P077B is a Type A DTC.

Diagnostic Aids

Inspect the output speed sensor, harness, connector and control solenoid valve assembly pins for metallic debris and output shaft machined face for

damage or misalignment. Proper torque of the output speed sensor mounting bolt is critical to proper output speed sensor operation. Use a terminal

test kit for any test that requires probing the control solenoid valve assembly harness connector or a component harness connector.

Reference Information

Schematic Reference

Automatic Transmission Controls Schematics (See: Transmission and Drivetrain/Automatic Transmission/Transaxle/Diagrams)

Connector End View Reference

Component Connector End Views (See: Diagrams/Connector Views)

Electrical Information Reference