GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Cadillac 🢒 2008 🢒 SLS 🢒 DTC 🢒 DTC P0741 or P0742

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 P0741:  Torque Converter Clutch (TCC) - Stuck Off

DTC P0742:  Torque Converter Clutch (TCC) - Stuck On

Circuit/System Description

The torque converter clutch (TCC) pressure control (PC) solenoid is part of the control solenoid (w/body and TCM) valve assembly and is not serviced separately. The shift solenoid (SS) 1 supplies transmission fluid to the TCC PC solenoid when commanded OFF. The TCC PC solenoid regulates transmission fluid through the TCC regulator valve in the lower valve body and the TCC control valve in the pump, to the TCC when commanded ON and exhausts fluid when commanded OFF. When the TCC is applied, the engine is coupled directly to the transmission.

Conditions for Running the DTC

P0741

    • Active the ignition voltage.
    • DTCs P0716, P0717, P0722, P0723, P2762, P2763, P2764, P0742 are not set.
    • The TFT is between 20-130°C (68-266°F).
    • The engine torque is greater than 50 N·m (36 lb ft).
    • The calculated throttle position is between 8-100 percent.
    • The 2nd gear ratio is between 2.21 and 2.54.
    • The 4th gear ratio is between 1.44 and 1.66.
    • The 5th gear is between 0.79 and 0.91.
    • The 6th gear is between 0.63 and 0.72.
    • TCC command apply.

P0742

    • Active the ignition voltage.
    • DTC P0716, P0717, P0722, P0723, P1751, P2762, P2763, P2764, P0741 are not set.
    • The TFT is between 20-130°C (68-266°F).
    • The engine torque is between 80 and 1492 N·m (59-1100 lb ft).
    • The calculated throttle position is between 8-100 percent.
    • The vehicle speed is greater than 16 km/h (10 mph).
    • Engine speed is between 500-6, 500 RPM.
    • The current ratio is between 0.63 and 2.54.
    • Commanded gear is more than 2nd, solenoid 1 is ON, the TCC commanded OFF.

Conditions for Setting the DTC

P0741

    • The TCC pressure exceeds 800 kPa for 2 seconds.
    • The TCM detects TCC slip error greater than 50 RPM for 6 seconds when the TCC is commanded ON.
    • This must occur 2 times.

P0742

    • The TCM detects the TCC slip between -12 and 13 RPM for 3 seconds when the TCC is commanded OFF.
    • This must occur 5 times.

Action Taken When the DTC Sets
    • DTC P0741 is a type B DTC.
    • DTC P0742 is a type A DTC.
    • Inhibit high gear in Hot Mode.
    • The TCM inhibits TCC.
    • The TCM freezes transmission adaptive functions.

Conditions for Clearing the DIC/DTC
    • DTC P0741 is a type B DTC.
    • DTC P0742 is a type A DTC.

Diagnostic Aids

When attempting to set transmission performance DTCs, observe the Freeze Frame and Failure Records to assist in duplicating the failure conditions. Ensure the transmission fluid level is correct and there are no leaks.

Reference Information

Schematic Reference

Automatic Transmission Controls Schematics

Connector End View Reference

    •  Automatic Transmission Inline 16-Way Connector End View
    •  Automatic Transmission Internal Connector End Views
    •  Automatic Transmission Related Connector End Views

DTC Type Reference

    •  Diagnostic Trouble Code (DTC) Type Definitions
    •  Diagnostic Trouble Code (DTC) List/Type

Electrical Information Reference

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

Scan Tool Reference

    •  Scan Tool Output Controls
    •  Scan Tool Data List
    •  Scan Tool Data Definitions

Special Tools

DT-47825 Control Solenoid Test Plate

Circuit/System Verification
  1. Perform the Transmission Fluid Check .
  2. Operate the vehicle in drive with the calculated throttle position greater than 8 percent and ensure TCC is commanded ON and OFF a minimum of 5 times.
    3. ⇒If the DTC resets, go to Component Testing.

Component Testing
  1. Perform the Control Solenoid Valve and Transmission Control Module Assembly Cleaning in an attempt to clean or free up a potential sticking valve of dirt or debris.
    2. ⇒If the DTC resets after the cleaning procedure perform the Control Solenoid Valve and Transmission Control Module Assembly Inspection .
  2. Perform the Control Solenoid Valve and Transmission Control Module Assembly Solenoid Performance Test to test for a stuck open or stuck closed TCC PC solenoid valve inside of the control solenoid (w/body and TCM) valve assembly.
    3. ⇒If a stuck open or closed valve is found, replace the control solenoid (w/body and TCM) valve assembly.
  3. Inspect the lower control valve body for a stuck valve, debris or damage.
    4. ⇒If you found a valve body concern, repair or replace the lower control valve body as necessary.
  4. Inspect the TCC control valve in the pump.
    5. ⇒If you found a TCC control valve concern, repair or replace the TCC control valve or pump as necessary.
  5. Inspect the torque converter assembly for damage or discoloration.
    6. ⇒If you found a torque converter assembly concern, replace the torque converter assembly as necessary.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

    •  Control Valve Lower Body and Upper Body Replacement
    •  Torque Converter Removal and Holding Fixture Installation
    •  Torque Converter Installation and Holding Fixture Removal
    •  Torque Converter Housing with Fluid Pump Removal
    •  Torque Converter Housing with Fluid Pump Installation
    •  Service Fast Learn Adapts
    •  Control Module References for TCC replacement, setup, and programming.