P0741
DTC P0741 or P0742Diagnostic 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) 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 to the TCC regulator valve in the lower valve body and the TCC control valve in the pump cover. When vehicle operating conditions are appropriate to apply the converter clutch, the transmission control module (TCM) will increase TCC PC current flow, duty cycle, to the TCC solenoid. The TCC PC solenoid directs fluid pressure to move the TCC control valve to the apply position, and moves the TCC regulator apply valve to the regulating position. The TCC regulator valve regulates TCC apply fluid pressure proportional to TCC solenoid pressure. When the TCC is fully applied, the engine is coupled directly to the transmission. TCC release is accomplished by the TCM decreasing current flow to the TCC PC solenoid. This results in decreasing the apply pressure which allows the TCC control valve to move to the release position. The TCM calculates torque converter slip speed based on engine speed and transmission input shaft speed.
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.
- The engine speed is 400 RPM or greater for 5.0 seconds.
- The ignition voltage is 8.6 volts or greater.
- The transmission fluid temperature (TFT) is between -7 to +130° C (19-266° F).
- The throttle position is 8 percent or greater.
- The engine torque is 50 Nm (36 lb ft) or higher.
- The 2nd gear ratio is between 2.67-3.07.
- The 3rd gear ratio is between 1.71-1.97.
- The 4th gear ratio is between 1.32-1.51.
- The 5th gear is between 0.93-1.07.
- The 6th gear is between 0.69-0.79.
- The TCC is commanded ON.
- The engine torque signal is valid.
- The 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.
- The commanded range is 2nd gear or higher.
- The ignition voltage is 8.6 volts or greater.
- The TFT is between -7 to +130° C (19-266° F).
- The throttle position is 8 percent or greater.
- The engine torque is 80 Nm (59 lb ft) or higher.
- The engine speed is 400 RPM or greater for 5 seconds.
- The vehicle speed is 16 km/h (10 mph) or greater.
- The gear ratio is between 0.69-3.07.
- The engine torque signal is valid.
- The throttle position signal is valid.
- The TCC is commanded OFF.
Conditions for Setting the DTC
P0741
- The TCC Pressure command is greater than 800 kPa (116 psi) for 2 seconds.
- The TCM detects TCC slip 50 RPM or greater for 5 seconds when the TCC is commanded ON. This must occur 3 times.
P0742
The TCM detects the TCC slip between -20 and +30 RPM for 2.5 seconds or greater when the TCC is commanded OFF. This must occur 6 times.
Action Taken When the DTC Sets
P0741
- DTC P0741 is a Type B DTC.
- The TCM inhibits 6th gear.
- The TCM inhibits TCC.
- The TCM forces hot mode shift pattern.
P0742
- DTC P0742 is a Type A DTC.
- The TCM freezes transmission adaptive functions.
- The TCM forces hot mode shift pattern.
Conditions for Clearing the DIC/DTC
P0741
DTC P0741 is a Type B DTC.
P0742
DTC P0742 is a Type A DTC.
Reference Information
Schematic Reference
Automatic Transmission Controls Schematics
Connector End View Reference
Component Connector End Views
Description and Operation
Transmission General Description
Electrical Information Reference
- Circuit Testing
- Connector Repairs
- Testing for Intermittent Conditions and Poor Connections
- Wiring Repairs
DTC Type Reference
Powertrain Diagnostic Trouble Code (DTC) Type Definitions
Scan Tool Reference
Control Module References for scan tool information
Circuit/System Verification
1. Perform the Transmission Fluid Level and Condition Check to verify correct fluid level and condition. Component Tests and General Diagnostics
2. Engine idling in Park, verify with a scan tool the Transmission ISS/OSS Supply Voltage parameter displays OK.
3. Engine idling in Park. Observe the Engine Speed and Transmission ISS parameters on the scan tool, while varying the engine speed. The Transmission ISS parameter should vary with engine speed and not drop out.
4. Operate the vehicle at 16-32 km/h (10-20 mph) while observing the Transmission OSS parameter on the scan tool. The Transmission OSS parameter should vary with the vehicle speed and not drop out.
5. Note
Perform a scan tool snapshot, during the road test.
Perform the road test. Initial Inspection and Diagnostic Overview Verify the transmission operation performs as indicated, in the road test instructions.
6. Review the scan tool snapshot transmission data parameters. Verify the engine and transmission data parameters display the correct values in all forward gear ranges:
- Engine Speed
- Engine Coolant Temperature
- Transmission ISS
- Transmission OSS
- Vehicle Speed
- Transmission Fluid Temperature
- TCC Pressure Control Solenoid Valve Pressure Command
- TCC Slip Speed
7. After performing the above steps, verify that the DTC does not reset by operating the vehicle within the conditions for running fault codes (DTC). You may also operate the vehicle within the conditions you observe from the freeze frame/failure records. If the vehicle passes the circuit/system verification procedure, then stop. Do not perform the circuit/system test or component test as this may result in unnecessary part replacement. Refer to Testing for Intermittent Conditions and Poor Connections.
Circuit/System Testing
1. Perform the Line Pressure Check. Component Tests and General Diagnostics Verify the transmission line pressures are within the specified ranges.
2. If not within the specified ranges, refer to Fluid Pressure High or Low. Fluid Pressure High or Low
3. Remove control solenoid valve assembly Q8 with ignition OFF. See Replacing control solenoid valve assembly and transmission control module.
4. Perform the Control Solenoid Valve and Transmission Control Module Assembly Solenoid Performance Test. Component Tests and General Diagnostics Test all solenoids on the Q8 control solenoid valve assembly. A pressure change should occur for each solenoid.
5. If the Q8 control solenoid valve assembly does not pass the performance test, replace the Q8 control solenoid valve assembly.
6. Listed in the table below are conditions for each component that could set DTC P0741 or P0742. Carefully inspect each component for that condition. Repair or replace as necessary.
Repair Instructions
Note
- Perform the Transmission Adaptive Values Learn following all transmission related repairs. Programming and Relearning
- Before replacing the TCM, perform the Control Solenoid Valve and Transmission Control Module Assembly Inspection. Control Solenoid Valve and Transmission Control Module Assembly Inspection
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
- Control Valve Lower Body and Upper Body Replacement
- Torque Converter Removal
- Torque Converter Installation
- Torque Converter and Differential Housing, Front Differential Transfer Drive Gear, and Front Differential Carrier Removal and Torque Converter and Differential Housing Installation
- Control Module References for control solenoid valve assembly replacement, setup, and programming