Buick Regal: DTC P0741 or P0742

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 P0741

Torque Converter Clutch (TCC) Pressure Control Solenoid Valve Stuck Off

DTC P0742

Torque Converter Clutch (TCC) System Stuck On

Circuit/System Description

The following inputs are used to determine TCC slip speed:

• Crankshaft Position Sensor
• Transmission ISS

When the amount of TCC slip is greater than desired, DTC P0741 sets.When the amount of TCC slip is less than desired, DTC P0742 sets.

Conditions for Running the DTC

• DTC P0711, P0712, P0713 P0717, P07BF, P07C0, P0722, P077C, P077D, P2761, P2763, P2764 = Not set
• { P0742 }Engine Speed=1000 to 3000 RPM & Engine Torque=Greater than 60 Nm (44 lb ft)
• { P0741 }Engine Speed=Less than 4001 RPM & Engine Torque=Greater than 0 Nm (0 lb ft)
• Ignition=9 to 32 V
• Transmission Range=Drive
• Transmission Fluid Temperature=Greater than 19ºC (66ºF)

Frequency the DTC runs=Continuously - After the running conditions are met - For 2 s

Conditions for Setting the DTC

P0741

Torque Converter Clutch=Applied & TCC Slip Speed=Greater than 100 RPM - For greater than 18 s

P0742

Torque Converter Clutch=Released & TCC Slip Speed=Less than 30 RPM - For greater than 24 s

Actions Taken When the DTC Sets

DTC P0741=Type B DTC

DTC P0742=Type C DTC

• { P0742 }Autostart/Autostop=Disabled - If equipped
• Learning=Disabled
• Torque Converter Clutch=Disabled

Conditions for Clearing the DTC

DTC P0741=Type B DTC

DTC P0742=Type C DTC

Reference Information

Schematic: Reference

Refer to Automatic Transmission Controls Wiring Schematics.

Connector End View: Reference

Refer to Component Connector End View Index.

Component View: Reference

Refer to Disassembled Views.

Description and Operation

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:Q39A Torque Converter Clutch Pressure Control Solenoid Valve

• 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. Clear the DTCs.

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

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

7. Verify DTC P0741, P0742 is not set.

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

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

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

1. Replace the component: Control Valve Body
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

8. 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

9. 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 Torque Converter Replacement
• Refer to Transmission Replacement
• For control module replacement, programming, and setup: Refer to Control Module: References

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