2010 Cadillac Truck Escalade RWD V8-6.0L Hybrid Page 2637
Transmission and Drivetrain/Automatic Transmission/Transaxle/Testing and Inspection/Component Tests and General
Diagnostics/6L45/6L50/6L80/6L90 - Automatic Transmission/Control Solenoid Valve and Transmission Control Module Assembly Input
Shaft Speed/Output Shaft Speed Input Test).
* Perform the Service Fast Learn Adapts (See: Transmission and Drivetrain/Automatic Transmission/Transaxle/Testing and
Inspection/Programming and Relearning) following all transmission related repairs.
2ML70 - Automatic Transmission
DTC P0721-P0723
Diagnostic Instructions
* Perform the Diagnostic System Check - Vehicle (See: Testing and Inspection/Initial Inspection and Diagnostic Overview/Diagnostic System
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
