P0741
DTC P0741 or P0742
Diagnostic Instructions
* Perform theDiagnostic System Check - Vehicle (Initial Inspection and Diagnostic Overview) prior to using this diagnostic procedure.
* ReviewStrategy Based Diagnosis (Initial Inspection and Diagnostic Overview) for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions (Initial Inspection and Diagnostic Overview) provides an overview of each diagnostic category.
DTC Descriptors
DTC P0741
- Torque Converter Clutch (TCC) System-Stuck Off
DTC P0742
- Torque Converter Clutch (TCC) System-Stuck On
Circuit/System Description
The torque converter clutch (TCC) solenoid is used to control the rate of TCC apply and release. This solenoid is a pressure controlling solenoid that is controlled by the transmission control module (TCM). The TCM varies the amount of electrical current to the TCC solenoid by changing the solenoid duty cycle. Varying the solenoid's duty cycle modulates the amount of fluid pressure supplied to the converter clutch regulator valve. The regulator valve then modifies the TCC fluid pressure. The TCC will apply or release with the change in TCC fluid pressure. The TCM compares the transmission input speed with the transmission turbine speed to determine converter slip speed; transmission input speed minus transmission turbine speed.
Conditions for Running the DTC
P0741
* Engine speed is between 200 RPM and 7500 RPM.
* Battery voltage is between 9-18 V.
* Transmission fluid temperature (TFT) is 5-130°C (41-266°F).
* Transmission is in a forward range.
* Throttle percentage is between 10 percent and 90 percent.
* Six or more seconds since last range change and TCC is commanded on.
* DTCs P0716, P0717, P0721, P0722, and P2764 are not active.
P0742
* TCC is commanded off.
* TCC slip speed is between -20 and 20 RPM.
* Throttle percentage is greater than 15 percent.
* Engine speed is less than 3500 RPM.
* Output speed is greater than 100 RPM.
* Battery voltage is between 9-18 V.
* TFT is 5-130°C (41-266°F).
* Transmission is in a forward range.
* Six or more seconds since last range change and TCC is commanded on.
* DTCs P0716, P0717, P0721, P0722, P0726, P0727, P2761, P2763, P2764 and U0100 are not active.
* Engine speed status must be normal.
Conditions for Setting the DTC
P0741
This DTC sets when the TCC is commanded on and the converter slip is greater than 80 RPM for 15 seconds. This must occur 2 consecutive times.
P0742 Condition 1 High Torque Condition
This DTC will set when the TCC is commanded off and the throttle is greater than 70 percent and net engine torque is greater than 275 Nm and the expected converter slip is not observed for 2 seconds.
P0742 Condition 2 High Acceleration Condition
This DTC will set when the TCC is commanded off and the output shaft acceleration is greater than 100 RPM/second and the expected converter slip is not observed for 5 seconds.
P0742 Condition 3 Accel/Decel/Accel Condition
This DTC will set when the TCC is commanded off when an output acceleration event is followed by an output deceleration event and followed by another output acceleration and the expected converter slip is not observed. An output acceleration event occurs when output shaft acceleration is greater than 40 RPM/second for greater than 4 seconds. An output deceleration event occurs when output shaft acceleration is -40 RPM/second for greater than 2.5 seconds.
Action Taken When the DTC Sets
P0741
* The TCM requests the engine control module (ECM) to illuminate the malfunction indicator lamp (MIL) on the second consecutive occurrence.
* DTC P0741 is stored in TCM History.
P0742
* The TCM requests the ECM to illuminate the MIL on the second consecutive occurrence.
* DTC P0742 is stored in TCM History.
* Reverse operation is disabled.
Conditions for Clearing the DTC
DTCs P0741 and P0742 are Type B DTCs.
Diagnostic Aids
* You must drive the vehicle in order to experience a condition.
* DTCs P0741 and P0742 may be caused by any of the following:
- An internal problem with the TCC
- A stuck or sticking TCC regulator valve
- A stuck or sticking TCC valve
- The TCC solenoid
Reference Information
Schematic Reference
Automatic Transmission Controls Schematics (Electrical Diagrams)
Connector End View Reference
Component Connector End Views (Connector Views)
Description and Operation
* Transmission General Description (Transmission General Description)
* Transmission Component and System Description (Transmission Component and System Description)
* Electronic Component Description (Electronic Component Description)
Electrical Information Reference
* Circuit Testing (Component Tests and General Diagnostics)
* Connector Repairs (Component Tests and General Diagnostics)
* Testing for Intermittent Conditions and Poor Connections (Component Tests and General Diagnostics)
* Wiring Repairs (Component Tests and General Diagnostics)
DTC Type Reference
Powertrain Diagnostic Trouble Code (DTC) Type Definitions (Diagnostic Trouble Code Descriptions)
Scan Tool Reference
Control Module References (Programming and Relearning) for scan tool information
Circuit/System Verification
1. Inspect the transmission fluid level. Refer to Transmission Fluid Check (Transmission Fluid Check) .
2. Perform a road test. Refer to Road Test (Road Test Procedure) .
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 on the Freeze Frame/Failure Records data.
Circuit/System Testing
Note
You must perform the Circuit/System Verification first.
Warning
Chock the wheels to prevent the vehicle from moving. Failure to chock the wheels can cause personal injury when the electrical system is repaired.
1. Perform a line pressure test. Refer to Line Pressure Check (Line Pressure Check) .
• If line pressure is low in all ranges, refer toLow Main Line Pressure in All Ranges (Low Main Line Pressure In All Ranges) .
• If line pressure is low in a specific range or ranges, refer toLow Main Line Pressure in Specific Ranges, Normal Pressure in Other Ranges (Low Main Line Pressure in Specific Ranges, Normal Pressure in Other Ranges) .
2. Engine idling, shift selector in park, record line pressure. Use the scan tool to command the TCC Control Solenoid ON and verify the TCC PC Sol. Pressure Command parameter changed from 0 kpa (0 psi) to 1600 kpa (232 psi). Record the line pressure after the pressure stabilizes. Line pressure should drop when the TCC Control Solenoid is commanded ON.
• If the pressure did not drop, refer toControl Valve Body Assembly Disassemble (Overhaul) andControl Valve Body Cleaning and Inspection (Overhaul) . If valve body inspection is normal, replace the TCC Solenoid. Refer to Control Valve Solenoid Replacement (SS1, SS2, SS3, TCC, and MAIN MOD) (Control Valve Solenoid Replacement (SS1, SS2, SS3, TCC, and MAIN MOD))Control Valve Solenoid Replacement (PCS1 and PCS2) (Control Valve Solenoid Replacement (PCS1 and PCS2)) . If line pressure still does not drop, refer toTransmission Fluid Pump Cover Disassemble (Overhaul) .
3. If the above tested normal, replace the torque converter. Refer to Torque Converter Replacement () .
Repair Instructions
Perform theDiagnostic Repair Verification (Verification Tests) after completing the diagnostic procedure.
* Control Valve Solenoid Replacement (SS1, SS2, SS3, TCC, and MAIN MOD) (Control Valve Solenoid Replacement (SS1, SS2, SS3, TCC, and MAIN MOD))Control Valve Solenoid Replacement (PCS1 and PCS2) (Control Valve Solenoid Replacement (PCS1 and PCS2))
* Torque Converter Replacement ()
Repair Verification
If another DTC is present, refer toDiagnostic Trouble Code (DTC) List - Vehicle (Diagnostic Trouble Code Descriptions) and perform the appropriate diagnostic procedure.