GM Service Manual Online
For 1990-2009 cars only

DTC P0722 or P0723 Hybrid

Diagnostic Instructions

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

DTC Descriptors

DTC P0722:  Output Speed Sensor Circuit Low Voltage

DTC P0723:  Output Speed Sensor Circuit Intermittent

Diagnostic Fault Information

Circuit

Short to Ground

Open/High Resistance

Short to Voltage

Signal Performance

OSS High Signal

P0722, P0723

P0722, P0723

P0722, P0723

P0722, P0723

OSS Low Signal

--

P0722, P0723

--

P0722, P0723

Typical Scan Tool Data

Output Speed Sensor Circuit Parameter Data

Circuit

Short to Ground

Open/High Resistance

Short to Voltage

Operating Conditions: Drive vehicle, normal operating temperature

Parameter Normal Range: 100-7.000 RPM

Transmission OSS

0 RPM

0 RPM

0 RPM

Circuit/System Description

The output speed sensor (OSS) system is a pulse generator consisting of a speed sensor assembly, located in the case extension, and a toothed vehicle speed sensor reluctor wheel, which is pressed onto the final drive carrier assembly. As the vehicle drives forward, the vehicle speed sensor reluctor wheel rotates. This rotation produces a variable AC signal in the pickup coil 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

    • No TP sensor DTCs P0120 or P0220.
    • No ISS DTCs P0716 or P0717.
    • No OSS DTC P0723.
    • The calc. throttle position is 8 percent or more.
    • The input shaft speed is 1,500-5,000 RPM.
    • The TCC slip speed is -20 RPM or more.
    • The TFT is -40°C (-40°F) or more.
    • The engine speed is greater than 500 RPM for 5 seconds.
    • The engine torque is greater than 50 N·m (37 lb ft).
    • The transmission range is not PARK or NEUTRAL.
    • The Hybrid control module (HCM) inhibits Hybrid operation.

P0723

    • No ISS DTCs P0716 or P0717.
    • No 1-2 SS electrical DTC P0974.
    • The time since the last gear selector range change is 6 seconds or more.
    • The output speed is 1,000 RPM or greater for 2 seconds.
    • No transmission OSS rise 500 RPM or greater for 2 seconds.
    • The ISS changes 500 RPM or less for 2 seconds.
    • The engine speed is greater than 500 RPM for 5 seconds.
    • The engine torque is greater than 50 N·m (37 lb ft).
    • The transmission range is not PARK or NEUTRAL.
    • The Hybrid control module (HCM) inhibits Hybrid operation.

Conditions for Setting the DTC

P0722

The engine must be above 50 N·m (37 lb ft) in Drive range.

P0723

The output shaft speed drops greater than 1,200 RPM for 3.25 seconds.

Action Taken When the DTC Sets

    • DTCs P0722 and P0723 are type B DTCs.
    • The TCM commands maximum line pressure.
    • The TCM freezes transmission adaptive functions.
    • The TCM calculates output speed based on ISS, engine speed, and commanded gear.

Conditions for Clearing the DTC

DTCs P0722 and P0723 are type B DTCs.

Reference Information

Schematic Reference

Automatic Transmission Controls Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

Electronic Component Description for OSS information

Electrical Information Reference

    •  Circuit Testing
    •  Connector Repairs
    •  Testing for Intermittent Conditions and Poor Connections
    •  Wiring Repairs

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Control Module References for scan tool information

Circuit/System Verification

  1. Operate the vehicle at 16-32 km/h (10-20 mph) while observing the scan tool transmission OSS parameter. The transmission OSS should vary with the vehicle speed and not drop out.
  2. 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 observe from the Freeze Frame/Failure Records data.

Circuit/System Testing

  1. Ignition OFF, disconnect the OSS harness connector.
  2. Test for 1,500-1,900 ohms between the OSS high signal circuit terminal A and OSS low signal circuit terminal B on the OSS.
  3. If not within the specified range, replace the OSS.
  4. Test for less than 10 ohms between terminal B of the OSS harness connector and terminal 41 of the TCM connector.
  5. If greater than the specified value, check circuit for an Open/High resistance.
  6. Test for less than 10 ohms between terminal A of the OSS harness connector and terminal 16 of the TCM connector.
  7. If greater than the specified value, check circuit for an Open/High resistance.
  8. Test for infinite resistance between the OSS harness terminal A and ground, and between terminal B and ground.
  9. If not the specified value, check each circuit for a short to ground.
  10. If all circuits test normal replace the TCM.

Component Testing

Verify the OSS resistance is between 1,500-1,900 ohms.

If the resistance is not within the specified range, replace the OSS.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the repair.

    •  Vehicle Speed Sensor Replacement
    •  Control Module References for TCM replacement, setup, and programming

DTC P0722 or P0723 Non-Hybrid

Diagnostic Instructions

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

DTC Descriptors

DTC P0722:  Output Speed Sensor Circuit Low Voltage

DTC P0723:  Output Speed Sensor Circuit Intermittent

Diagnostic Fault Information

Circuit

Short to Ground

Open/High Resistance

Short to Voltage

Signal Performance

OSS High Signal

P0722, P0723

P0722, P0723

P0722, P0723

P0722, P0723

OSS Low Signal

--

P0722, P0723

--

P0722, P0723

Typical Scan Tool Data

Output Speed Sensor Circuit Parameter Data

Circuit

Short to Ground

Open/High Resistance

Short to Voltage

Operating Conditions: Drive vehicle, normal operating temperature

Parameter Normal Range: 100-7000 RPM

Transmission OSS

0 RPM

0 RPM

0 RPM

Circuit/System Description

The output speed sensor (OSS) system is a pulse generator consisting of a speed sensor assembly, located in the case extension, and a toothed vehicle speed sensor reluctor wheel, which is pressed onto the final drive carrier assembly. As the vehicle drives forward, the vehicle speed sensor reluctor wheel rotates. This rotation produces a variable AC signal in the pickup coil 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

    • No TP sensor DTCs P0120 or P0220.
    • No ISS DTCs P0716 or P0717.
    • No OSS DTC P0723.
    • The calc. throttle position is 8 percent or more.
    • The input shaft speed is 1,500-5,000 RPM.
    • The TCC slip speed is -20 RPM or more.
    • The TFT is -40°C (-40°F) or more.
    • The engine speed is greater than 500 RPM for 5 seconds.
    • The engine torque is greater than 50 N·m (37 lb ft).
    • The transmission range is not PARK or NEUTRAL.

P0723

    • No ISS DTCs P0716 or P0717.
    • No 1-2 SS electrical DTC P0974.
    • The time since the last gear selector range change is 6 seconds or more.
    • The output speed is 1,000 RPM or greater for 2 seconds.
    • No transmission OSS rise 500 RPM or greater for 2 seconds.
    • The ISS changes 500 RPM or less for 2 seconds.
    • The engine speed is greater than 500 RPM for 5 seconds.
    • The engine torque is greater than 50 N·m (37 lb ft).
    • The transmission range is not PARK or NEUTRAL.

Conditions for Setting the DTC

P0722

    • The output shaft speed is 200 RPM or less for 4.5 seconds.
    • The engine must be above 50 N·m (37 lb ft) in Drive range.

P0723

The output shaft speed drops greater than 1,200 RPM for 3.25 seconds.

Action Taken When the DTC Sets

    • DTCs P0722 and P0723 are type B DTCs.
    • The TCM commands maximum line pressure.
    • The TCM freezes transmission adaptive functions.
    • The TCM calculates output speed based on ISS, engine speed, and commanded gear.

Conditions for Clearing the DTC

DTCs P0722 and P0723 are type B DTCs.

Reference Information

Schematic Reference

Automatic Transmission Controls Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

Electronic Component Description for OSS information

Electrical Information Reference

    •  Circuit Testing
    •  Connector Repairs
    •  Testing for Intermittent Conditions and Poor Connections
    •  Wiring Repairs

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Control Module References for scan tool information

Circuit/System Verification

  1. Operate the vehicle at 16-32 km/h (10-20 mph) while observing the scan tool transmission OSS parameter. The transmission OSS should vary with the vehicle speed and not drop out.
  2. 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 observe from the Freeze Frame/Failure Records data.

Circuit/System Testing

  1. Ignition OFF, disconnect the OSS harness connector.
  2. Test for 1,500-1,900 ohms between the OSS high signal circuit terminal A and OSS low signal circuit terminal B on the OSS.
  3. If not within the specified range, replace the OSS.
  4. Test for less than 10 ohms between terminal B of the OSS harness connector and terminal 41 of the TCM connector.
  5. If greater than the specified value, check circuit for an Open/High resistance.
  6. Test for less than 10 ohms between terminal A of the OSS harness connector and terminal 16 of the TCM connector.
  7. If greater than the specified value, check circuit for an Open/High resistance.
  8. Test for infinite resistance between the OSS harness terminal A and ground, and between terminal B and ground.
  9. If not the specified value, check each circuit for a short to ground.
  10. If all circuits test normal replace the TCM.

Component Testing

Verify the OSS resistance is between 1,500-1,900 ohms.

If the resistance is not within the specified range, replace the OSS.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the repair.

    •  Vehicle Speed Sensor Replacement
    •  Control Module References for TCM replacement, setup, and programming