Buick Regal: DTC P0776, P07A2, or P2719

Diagnostic Instructions

• Perform the Diagnostic System Check prior to using this diagnostic procedure: Refer to Diagnostic System Check - Vehicle
• Review the description of Strategy Based Diagnosis:Strategy Based Diagnosis
• An overview of each diagnostic category can be found here: Refer to Diagnostic Procedure Instructions

DTC Descriptor

DTC P0776

Transmission Control Solenoid Valve 2 Stuck Off

DTC P07A2

Transmission Clutch 1 Performance

DTC P2719

Transmission Control Solenoid Valve 4 Performance

Circuit/System Description

When in Drive, the solenoid valve controls pressure to the C1 clutch regulator valve, or when in Reverse, the solenoid valve controls pressure to the C3 clutch regulator valve. These DTC's indicate a hydraulic /mechanical problem with the valve body or fluid pressure which is controlled by solenoid valves and is part of the control solenoid valve assembly which has no serviceable parts. With a loss of pressurized fluid, an incorrect gear ratio may result causing a Neutral condition or NO drive in all gears.

Conditions for Running the DTC

P0776, P07A2, P2719

• DTC P0563, P0601, P0602, P0604, P0711, P0712, P0713, P0717, P07BF, P07C0, P0722, P0741, P0742, P0748, P077C, P077D, P0798, P0962, P0963, P0970, P0971 = Not set
• Battery Voltage=9 to 32 V
• { P0776 }Current Gear=1, 2, 3, 4, 5
• { P07A2 }Current Gear=1, 2, 3, 4, 6
• { P2719 }Current Gear=Reverse & Shift Solenoid Valve 1 Command=Off
• Engine Speed=Greater than 600 RPM
• Garage Shift =No
• Ignition=On
• Transmission Fluid Temperature=Warmer than -10ºC (14ºF)
• Transmission ISS=Less than 200 RPM
• Transmission OSS=Less than 501 RPM
• Transmission Torque Command=Off

Frequency the DTC runs=Continuously - After the running conditions are met

Conditions for Setting the DTC

Condition 1

• Transmission Fluid Temperature=Warmer than 0ºC (32ºF)
• The difference between the following parameters is less than 150 RPM:Engine Speed & Transmission Input Speed - For greater than 3 s

Condition 2

• Transmission Fluid Temperature=-10 to -1ºC (14 to 30ºF)
• The difference between the following parameters is less than 300 RPM:Engine Speed & Transmission Input Speed - For greater than 10 s

Actions Taken When the DTC Sets

DTCs listed in the DTC Descriptor Category=Type C DTC - Exceptions listed below - Additional actions taken:

• Engagement of Reverse Gear=Shift Solenoid Valve 1 Command - ON
• Learning=Disabled

DTC P0776=DTC A - Additional actions taken:

• Torque Converter Clutch Solenoid Control=Disabled
• Manual Shift Control=Disabled

Conditions for Clearing the DTC

• DTCs listed in the DTC Descriptor Category=Type C DTC
• DTC P0776=DTC A

Reference Information

Schematic: Reference

Refer to Automatic Transmission Controls Wiring Schematics.

Connector End View: Reference

• Refer to Component Connector End View Index
• Refer to Inline Harness Connector End View Index

Component View: Reference

Refer to Disassembled Views.

Description and Operation

• Refer to Electronic Component Description
• Refer to Transmission General Description

Electrical Information: Reference

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

DTC Type: Reference

Refer to Powertrain Diagnostic Trouble Code (DTC) Type Definitions.

Scan Tool: Reference

Refer to Control Module: References.

Circuit/System Verification

1. Ignition - On / Vehicle - In Service Mode.

2. Verify there are no DTCs set related to the following system/component:

• Q27A Pressure Control Solenoid Valve 1
• Q27B Pressure Control Solenoid Valve 2
• Q27D Pressure Control Solenoid Valve 4
• If other DTCs are set

Refer to: Diagnostic Trouble Code (DTC) List - Vehicle

• Go to next step: If no other DTCs are set

3. Verify the condition does not exist:Incorrect fluid level or condition - Transmission - Refer to Transmission Fluid Level and Condition Check.

• If a condition exists

Repair or replace as necessary.

• Go to next step: If no condition exists

4. Verify there are no DTCs set related to the following system/component:K173 Transmission Range Control Module - If equipped

• If any DTC is set

Refer to: Diagnostic Trouble Code (DTC) List - Vehicle

• Go to next step: If no DTC is set

5. Clear the DTCs.

6. Perform the configuration/reset function: Refer to Learned Values Reset.

7. Road test the vehicle. - Refer to Road Test.

8. Verify DTC P0776, P07A2, P2719 is not set.

• {Test failed 1 time (s) }If any of the DTCs are set

1. Replace the component: Control Valve Body
2. Refer to:Step 5

• {Test failed 2 time (s) }If any of the DTCs are set

1. Replace the component: K71 Transmission Control Module
2. Refer to:Step 5

• {Test failed 3 time (s) }If any of the DTCs are set

1. Replace the component: T12 Automatic Transmission Assembly
2. Refer to:Step 5

• Go to next step: If none of the DTCs are set

9. Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.

Verify the DTC does not set.

• If the DTC sets

Refer to:Step 1

• Go to next step: If the DTC is not set

10. All OK.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the repair: Refer to Diagnostic Repair Verification

• Refer to Control Valve Body Replacement
• Refer to Transmission Replacement
• For control module replacement, programming, and setup: Refer to Control Module: References

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