P0741
DTC P0741 or P0742
Diagnostic Instructions
* Perform the Diagnostic System Check - Vehicle Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis Strategy Based Diagnosis for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions Diagnostic Procedure Instructions 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) pressure control (PC) solenoid is part of the control solenoid valve assembly which has no serviceable components. The TCC PC solenoid is a normally low pressure control solenoid. The TCC PC solenoid regulates transmission fluid pressure to the TCC regulator valve in the lower valve body and the TCC control valve in the fluid pump assembly. When vehicle operating conditions are appropriate to apply the torque converter clutch, the transmission control module (TCM) will increase TCC PC current flow (duty cycle) thereby increasing pressure to move the TCC control valve into the apply position. When the TCC is fully applied, the engine is coupled directly to the transmission. TCC release is accomplished by the TCM decreasing current flow, dropping the apply pressure thereby allowing the TCC control valve to move to the release position. The TCM calculates torque converter slip speed based on the RPM signal from the input speed sensor (ISS) and engine RPM provided by the engine control module (ECM).
Conditions for Running the DTC
P0741
* DTC P0101, P0102, P0103, P0106, P0107, P0108, P0171, P0172, P0174, P0175, P0201, P0202, P0203, P0204, P0205, P0206, P0207, P0208, P0300, P0301, P0302, P0303, P0304, P0305, P0306, P0307, P0308, P0401, P042E, P0716, P0717, P0722, P0723, P0741, P0742, P2763, or P2764 is not set.
* Engine speed is 400 RPM or greater for 5 seconds.
* Ignition voltage is 9.0 volts or greater.
* Transmission fluid temperature (TFT) is between -7 to +137°C (19-279°F).
* Throttle position is 8 percent or greater.
* Engine torque is 50 Nm (36 lb ft) or greater.
* 2nd gear ratio is between 2.75-3.17.
* 3rd gear ratio is between 1.78-2.04.
* 4th gear ratio is between 1.35-1.55.
* 5th gear ratio is between 0.93-1.07.
* 6th gear ratio is between 0.70-0.80.
* TCC is commanded ON.
* Engine torque signal is valid.
* Throttle position signal is valid.
P0742
* DTC P0101, P0102, P0103, P0106, P0107, P0108, P0171, P0172, P0174, P0175, P0201, P0202, P0203, P0204, P0205, P0206, P0207, P0208, P0300, P0301, P0302, P0303, P0304, P0305, P0306, P0307, P0308, P0401, P042E, P0716, P0717, P0722, P0723, P0741, P0742, P2763, or P2764 is not set.
* Engine speed is greater than 400 RPM for 5 seconds.
* Ignition voltage is 9.0 volts or greater.
* TFT is between 15-137°C (59-279°F).
* Calculated throttle position was 10 percent or greater and has not dropped below 2 percent.
* Engine torque is greater than 60 Nm (44 lb ft).
* Vehicle speed greater than 1 km/h (0.6 mph).
* TCC is commanded OFF.
Conditions for Setting the DTC
P0741
TCM detects TCC slip greater than 130 RPM for 5 seconds with a TCC commanded ON pressure of 500 kPa or greater. This must occur 2 times during the same ignition cycle.
P0742
TCM detects the TCC slip is between -50 and +30 RPM for 1 second or greater when the TCC is commanded OFF 8 times during the same ignition cycle.
Action Taken When the DTC Sets
P0741
* DTC P0741 is a Type B DTC.
* TCM inhibits high gear.
* TCM initiates the Hot Mode shift pattern.
* TCM commands the TCC OFF.
P0742
* DTC P0742 is a Type A DTC.
* TCM initiates Hot Mode shift pattern.
* TCM freezes transmission adaptive functions.
* TCM commands the TCC ON.
* TCM inhibits neutral idle.
Conditions for Clearing the DIC/DTC
P0741
DTC P0741 is a Type B DTC.
P0742
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 6T30/6T40/6T45/6T50 - Automatic Transmission
Connector End View Reference
Component Connector End Views Connector End Views By Name
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 Circuit Testing
* Connector Repairs Connector Repairs
* Testing for Intermittent Conditions and Poor Connections Testing for Intermittent Conditions and Poor Connections
* Wiring Repairs Wiring Repairs
DTC Type Reference
Powertrain Diagnostic Trouble Code (DTC) Type Definitions Powertrain Diagnostic Trouble Code (DTC) Type Definitions
Scan Tool Reference
Control Module References Programming and Relearning for scan tool information
Circuit/System Verification
1. Review the TCM failure records to determine if DTC P0716, P0717, P07BF, or P07C0 was set.
• If DTC P0716, P0717, P07BF, or P07C0 was set
Diagnose that DTC first. Refer to Diagnostic Trouble Code (DTC) List - Vehicle Diagnostic Trouble Code (DTC) List - Vehicle.
• If DTC P0716, P0717, P07BF, or P07C0 was not set
2. Verify correct transmission fluid level and condition. Refer to Transmission Fluid Level and Condition Check Transmission Fluid Level and Condition Check.
3. Ignition ON, clear the TCM DTCs.
4. Perform the Road Test Initial Inspection and Diagnostic Overview. Verify the transmission operation performs as indicated in the road test instructions and DTCs P0741 or P0742 did not set.
• If DTC P0741 or P0742 sets
Refer to Circuit/System Testing below.
• If DTC P0741 or P0742 did not set
5. After performing the above steps, verify that the DTC does not reset by operating the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions you observe from the Freeze Frame/Failure Records data. If the vehicle passes the Circuit/System Verification procedure, then STOP. Do not perform the Circuit/System Testing or Component Testing as this may result in an unnecessary part replacement. Refer to Testing for Intermittent Conditions and Poor Connections Testing for Intermittent Conditions and Poor Connections.
Circuit/System Testing
1. Perform the Line Pressure Check Line Pressure Check. Verify the transmission line pressures are within the range specified in the Line PC Solenoid Valve Pressure table. Refer to Solenoid Valve Pressure (Gen 1) Solenoid Valve Pressure (Gen 1)Solenoid Valve Pressure (Gen 2) Solenoid Valve Pressure (Gen 2).
• If the line pressures are not within the specified ranges
Refer to Fluid Pressure High or Low Fluid Pressure High or Low.
• If the line pressures are within the specified ranges
2. Ignition OFF, remove the Q8 control solenoid valve assembly. Refer to Control Solenoid Valve and Transmission Control Module Assembly Replacement Service and Repair.
3. Perform the Control Solenoid Valve and Transmission Control Module Assembly Solenoid Performance Test Control Solenoid Valve and Transmission Control Module Assembly Solenoid Performance Test. Test all solenoids on the Q8 control solenoid valve assembly. A pressure change should occur for each solenoid tested.
• If a pressure change does not occur for each solenoid tested
Replace the Q8 control solenoid valve assembly.
• If a pressure change occurs for each solenoid
4. Listed in the table below are conditions for each component that could set a DTC P0741 or P0742. Carefully inspect each component for that condition. Repair or replace as necessary.
Repair Instructions
Perform the Diagnostic Repair Verification Verification Tests after completing the diagnostic repair.
Note:
Before replacing the TCM, perform the Control Solenoid Valve and Transmission Control Module Assembly Inspection Control Solenoid Valve and Transmission Control Module Assembly Inspection.
* Refer to Control Module References Programming and Relearning for control solenoid valve assembly replacement, programming and setup.
* Perform the Transmission Adaptive Values Learn Programming and Relearning following all transmission related repairs.
* Perform the Torque Converter Removal 2. Torque Converter Removal and the Torque Converter Installation 54. Torque Converter Installation.