2010 Cadillac Truck Escalade/ESV RWD V8-6.2L Page 2264

2010 Cadillac Truck Escalade/ESV RWD V8-6.2L Page 2264

Check - Vehicle) prior to using this diagnostic procedure.

* Review Strategy Based Diagnosis (See: Testing and Inspection/Initial Inspection and Diagnostic Overview/Strategy Based Diagnosis) for an

overview of the diagnostic approach.

* Diagnostic Procedure Instructions (See: Testing and Inspection/Initial Inspection and Diagnostic Overview/Diagnostic Procedure

Instructions) provides an overview of each diagnostic category.

DTC Descriptors

DTC P0721

- Output Speed Sensor Performance

DTC P0722

- Output Speed Sensor Circuit Low Voltage

DTC P0723

- Output Speed Sensor Circuit Intermittent

Diagnostic Fault Information

Typical Scan Tool Data

Circuit/System Description

The Automatic Transmission Output Shaft Speed Sensor assembly has 2 internal hall-effect type sensors, and is capable of sensing both speed and

direction. The Automatic Transmission Output Shaft 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 Automatic Transmission Output Shaft 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 TCM for speed

and direction and is transmitted through the data communication 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 ABS wheel speed sensor

signal.

Conditions for Running the DTC

P0721

The ignition is ON.

P0722

* No OSS DTCs P0721 or P0723.

* The selected range is not PARK or NEUTRAL.

* The vehicle speed is greater than 16 km/h (10 mph).

P0723

* No Automatic Transmission Output Shaft Speed Sensor DTCs P0721 or P0722.

* The engine run time is greater than 6 seconds.

Conditions for Setting the DTC