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6L50/6L80/6L90 - Automatic Transmission




DTC P0722 or P0723

Diagnostic Instructions

* Perform the Diagnostic System Check - Vehicle (Diagnostic System Check - Vehicle) prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis (Strategy Based Diagnosis) for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions (Diagnostic Procedure Instructions) provides an overview of each diagnostic category.

DTC Descriptors
DTC P0722
- Output Speed Sensor (OSS) Circuit Low Voltage

DTC P0723
- Output Speed Sensor (OSS) Intermittent

Diagnostic Fault Information





Typical Scan Tool Data









Circuit/System Description

The automatic transmission (AT) input and output speed sensor (ISS and OSS) assembly each are part of a single harness. The OSS is a hall-effect type sensor. The ISS/OSS mounts to the control valve upper body assembly. The sensor end faces the output shaft housing machined slots. The sensor receives 8.3-9.3 volts on the ISS/OSS supply voltage circuit from the control solenoid valve assembly. As the output shaft rotates, the sensor produces a signal frequency based on the machined slots of the output shaft housing. This signal is transmitted through the OSS signal circuit to the control solenoid valve assembly. The control solenoid valve assembly uses the OSS signal to determine line pressure, transmission shift patterns, torque converter clutch (TCC) slip speed and gear ratio.

Conditions for Running the DTC

P0722
* DTCs P0101, P0102, P0103, P0121, P0122, P0123, P0716, P0717, or P0722 are not set.
* Ignition voltage is 8.6 volts or greater.
* The engine speed is 500 RPM or greater for 5 seconds.
* The TCM must receive a valid torque signal from the ECM.
* The engine torque is between 50-1,492 Nm (36-1,100 lb ft).
* Accelerator pedal position signal is valid.
* Transmission fluid temperature (TFT) is greater than 0°C (32°F).
* The selected range is not PARK or NEUTRAL.
* The transmission input speed is between 653-5350 RPM.
* The throttle position is greater than 5 percent.

P0723
* DTCs P0101, P0102, P0103, P0121, P0122, P0123, P0716, P0717, P0722, P0723, P0973, P0974, P0976, or P0977 are not set.
* Ignition voltage is 8.6 volts or greater.
* The engine speed is 3200 RPM or greater for 5 seconds.
* Greater than 5 seconds since last range change.
* The TCM must receive a valid torque signal from the ECM.
* Accelerator pedal position signal is valid.

Conditions for Setting the DTC

P0722
* The TCM detects no output shaft speed when there is vehicle speed.
* The transmission output speed is 35 RPM or less for 4 seconds.

P0723
* The TCM detects an unrealistic drop in output shaft speed.
* The transmission input speed has not changed by more than 4100 RPM for 2 seconds.
* The transmission output speed has not changed by more than 8200 RPM for 2 seconds.
* The transmission output speed drops 650 RPM and does not recover for 1.5 seconds.

Action Taken When the DTC Sets

P0722
* DTC P0722 is a Type A DTC.
* The transmission defaults to second gear.
* The TCM enables torque management.
* The TCM freezes transmission adaptive functions.
* The TCM turns OFF all solenoids.
* The TCM turns OFF the TCC solenoid.

P0723
* DTC P0723 is a Type A DTC.
* The high side driver is turned OFF.
* The TCM turns OFF all solenoids.
* The TCM freezes transmission adaptive functions.
* The TCM enables torque management.

Conditions for Clearing the DIC/DTC

DTCs P0722 and P0723 are Type A DTCs.

Diagnostic Aids

Inspect the ISS/OSS, harness, connector and control solenoid valve assembly for metallic debris and output shaft housing machined slots for damage or misalignment. Proper torque of the ISS/OSS mounting bolt is critical to proper speed sensor operation.

Reference Information
Schematic Reference

Automatic Transmission Controls Schematics (6L45/6L50/6L80/6L90 - Automatic Transmission)
Connector End View Reference

* Component Connector End Views (Connector End Views By Name)
* Inline Harness Connector End Views (Connector End Views By Number)

Electrical Information Reference

* Circuit Testing (Circuit Testing)
* Connector Repairs (Connector Repairs)
* Testing for Intermittent Conditions and Poor Connections (Testing for Intermittent Conditions and Poor Connections)
* Wiring Repairs (Wiring Repairs)

Description and Operation

Electronic Component Description (Electronic Component Description)
DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions (Powertrain Diagnostic Trouble Code (DTC) Type Definitions)
Scan Tool Reference

Control Module References (Programming and Relearning) for scan tool information
Special Tools

DT-47825-10 - Jumper Harness

For equivalent regional tools, refer to Special Tools (6L45/6L50/6L80/6L90 - Automatic Transmission).

Circuit/System Verification

1. Ignition ON, verify with a scan tool the transmission ISS/OSS supply voltage test status parameter displays OK.
2. Operate the vehicle at 16-32 km/h (10-20 mph) while observing the Transmission OSS parameter on the scan tool. The Transmission OSS parameter should vary with the vehicle speed and not drop out.
3. Operate the vehicle within the Conditions for Running the DTC to verify the DTC does not reset. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.

Circuit/System Testing

Note: You must perform the Circuit/System Verification first.

1. Ignition OFF, remove the control solenoid valve assembly. Refer to Control Solenoid Valve and Transmission Control Module Assembly Replacement (6L45/6L50/6L80/6L90 - Automatic Transmission).
2. Connect the DT-47825-10 - jumper harness between the vehicle wire harness electrical connector, and the control solenoid valve assembly electrical connector.
3. Ignition ON, test for 8.3-9.3 volts between the ISS/OSS voltage circuit terminal B on the Q8 control solenoid valve assembly and ground at the transmission case.

• If not within the specified range, replace the control solenoid valve assembly.

4. Perform the Control Solenoid Valve and Transmission Control Module Assembly Input Shaft Speed/Output Shaft Speed Input Test (Control Solenoid Valve and Transmission Control Module Assembly Input Shaft Speed/Output Shaft Speed Input Test).
5. Inspect the machined slots on the output shaft housing outer surface for damage or misalignment. Repair or replace as necessary.
6. If all of the above test normal, replace the B14A/B14C ISS/OSS assembly.

Repair Instructions

Perform the Diagnostic Repair Verification (Verification Tests) after completing the diagnostic procedure.

* Perform the Input and Output Speed Sensor Replacement (Service and Repair).
* Control solenoid valve assembly - refer to Control Module References (Programming and Relearning) for replacement, setup, and programming.
* Perform the Control Solenoid Valve and Transmission Control Module Assembly Input Shaft Speed/Output Shaft Speed Input Test (Control Solenoid Valve and Transmission Control Module Assembly Input Shaft Speed/Output Shaft Speed Input Test).
* Perform the Service Fast Learn Adapts (Programming and Relearning) following all transmission related repairs.

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