DTC P0741 or P0742

/ 9-4x / 2011 / 4. Transmission / Automatic Transmission (6T70/6T75) / Fault diagnosis, diagnostic trouble codes / 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) 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 the vehicle's running conditions are suitable to engage the torque converter's clutch, the transmission control module (TCM) increases the TCC PC-current flow to the TCC-solenoid valve. The TCC PC solenoid valve controls the fluid pressure to move the TCC control valve to the activated position and move the TCC regulator's activation valve to control mode. The TCC regulator valve regulates the TCC activation's fluid pressure proportional to the TCC solenoid valve pressure. When TCC is fully activated, the engine is connected directly to the transmission. TCC disengagement occurs through TCM reducing the current flow to the TCC PC solenoid valve. This results in a reduced activation pressure, which means that the TCC control valve moves to disengagement mode. TCM calculates the torque converter's slipping speed according to the engine speed and the speed of the transmission's input shaft.

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.

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 . 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 you complete the steps described above, check the diagnostic trouble code is not reset by driving the vehicle according to the conditions for running diagnostic trouble codes (DTC). You can also drive the vehicle according to the conditions you see in 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 . Verify the transmission line pressures are within the specified ranges.

2.	If not within the specified ranges, refer to 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 Test of the control solenoid valve assembly and the transmission control module's solenoid performance . Test all solenoid valves 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.

DTCs	Component	Condition
P0741 P0742	Upper Valve Body	TCC Control Valve • Stuck TCC control valve • Damaged valve/bore
P0741 P0742	Upper Valve Body	TCC Regulator Valve • Stuck TCC regulator valve • Damaged valve/bore
P0741 P0742	Q8 Control Solenoid Valve Assembly	TCC Pressure Control Solenoid • Not pressurizing - Stuck OFF or leaking • Not exhausting - Stuck ON • Control signal fluid supply leak - valve body filter plate assembly cracked or damaged gasket seal
P0741	Torque Converter	• Torque converter clutch delamination or material worn off • Damaged seal • Converter bolts too long - damaging the clutch apply surface
P0741	Support	Damaged seal
P0741 P0742	A/Trans Case Cover (403)	Release blow-off • Not seating/sealing • Damaged Spring
P0741	Upper Valve Body	Release exhaust port/orifice plugged or blocked.
P0741	Turbine Shaft	Turbine shaft O-ring seal cut or damaged

Repair Instructions

Note
•	Perform the Resetting of the transmission's adaption after all transmission repairs.
•	Before replacing the TCM, perform the 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

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