4T80-E - Automatic Transaxle
DTC P0722 or P0723
Diagnostic Instructions
* Perform the Diagnostic System Check - Vehicle (Initial Inspection and Diagnostic Overview) prior to using this diagnostic procedure.
* ReviewStrategy Based Diagnosis (Initial Inspection and Diagnostic Overview) for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions (Initial Inspection and Diagnostic Overview) provides an overview of each diagnostic category.
DTC Descriptors
DTC P0722
- Output Speed Sensor (OSS) Circuit Low Voltage
DTC P0723
- Output Speed Sensor (OSS) Circuit Intermittent
Diagnostic Fault Information
Circuit/System Description
The output shaft speed (OSS) sensor is a pulse generator consisting of a speed sensor assembly, located in the case extension, and a toothe D reluctor wheel, which is pressed onto the final drive carrier assembly. As the vehicle drives forward, the reluctor wheel rotates. This rotation produces a variable AC signal in the pick-up coil of the output shaft sensor that is proportional to vehicle speed. The transmission control module (TCM) uses this signal in order to calculate vehicle speed, shift timing, and gear ratios.
Conditions for Running the DTC
P0722
* DTCs P0121, P0122, P0123, P0716, P0717, or P0723 are not set.
* The ignition voltage is between 8 and 18 volts.
* The engine speed is between 500 and 6,500 RPMs for 5 seconds.
* The transmission is not in PARK or NEUTRAL.
* The TP sensor is 8 percent or greater.
* The transmission input shaft speed is 1,500-6,500 RPM.
* The transmission temperature is greater than -40°C (-40°F).
* The TCC slip speed is greater -20 RPM.
P0723
* DTCs P0716, P0717, or P0974 are not set.
* The ignition voltage is between 8 and 18 volts.
* The engine speed is between 500 and 6,500 RPMs for 5 seconds.
* The transmission is not in PARK or NEUTRAL.
* The transmission input shaft speed has not changed by 500 RPM or greater for at least 2 seconds.
* The transmission output shaft speed is greater than 321 RPM for 2 seconds.
Conditions for Setting the DTC
P0722
The transmission output shaft speed is 64 RPM or less for 4.5 seconds.
P0723
The transmission output shaft speed drops more than 385 RPM for 3 seconds.
Action Taken When the DTC Sets
P0722 and P0723 are Type B DTCs.
Conditions for Clearing the DTC
P0722 and P0723 are Type B DTCs.
Reference Information
Schematic Reference
Automatic Transmission Controls Schematics (Electrical Diagrams)
Connector End View Reference
Component Connector End Views (Connector Views)
Description and operation
Transmission General Description (Transmission General Description)
Electrical Information Reference
* Circuit Testing (Component Tests and General Diagnostics)
* Connector Repairs (Component Tests and General Diagnostics)
* Testing for Intermittent Conditions and Poor Connections (Component Tests and General Diagnostics)
* Wiring Repairs (Component Tests and General Diagnostics)
DTC Type Reference
Powertrain Diagnostic Trouble Code (DTC) Type Definitions (Diagnostic Trouble Code Descriptions)
Scan Tool Reference
Control Module References (Programming and Relearning)
Special Tools
* J 35616 GM-Approved Terminal Test Kit
* J 44152 Jumper Harness (20 pins)
Circuit/System Verification
1. Monitor OSS parameter on the scan tool. The OSS parameter should increase as the drive wheel speed increases.
2. Operate the vehicle within the conditions for running the DTC. You may also operate the vehicle within the conditions that are captured in the Freeze Frame/Failure Records List.
Circuit/System Testing
1. Ignition OFF, disconnect the TCM X1 connector.
2. Measure for 1,260-1,911 ohms between the OSS high signal circuit terminal 41 and the OSS low signal circuit terminal 16.
• If greater than the specified range test the OSS high signal and the OSS low signal circuits for an open/high resistance. If the circuits/connections test normal, replace the input shaft speed sensor.
• If less than 820 ohms test the OSS high signal and the OSS low signal circuits for a shorted together condition. If the circuits/connections test normal, replace the input shaft speed sensor.
3. Measure for more than 10 ohms of resistance between the OSS high signal circuit terminal 41 and ground.
• If less than the specified range, repair the short to ground.
4. Measure for more than 10 ohms of resistance between the OSS low signal circuit terminal 16 and ground.
• If less than the specified range, repair the short to ground.
5. Connect the TCM connector. Disconnect the transmission 20-way connector.
6. Ignition ON, test the OSS high signal circuit terminal 41 for a short to voltage.
• If all circuits test normal, test or replace the internal transmission wiring harness or the OSS sensor.
Repair Instructions
Perform the Diagnostic Repair Verification (Verification Tests) after completing the repair.
* Input Speed Sensor and Wiring Harness Removal (Overhaul)
* Control Module References (Programming and Relearning) for ECM replacement, setup and programming