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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 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.
    • The engine speed is greater than 400 RPM for 5 seconds.
    • The ignition voltage is 9.0 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 N·m (36 lb ft) or greater.
    • The 2nd gear ratio is between 2.75-3.17.
    • The 3rd gear ratio is between 1.78-2.04.
    • The 4th gear ratio is between 1.35-1.55.
    • The 5th gear is between 0.93-1.07.
    • The 6th gear is between 0.70-0.80.
    • 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 engine speed is greater than 400 RPM for 5 seconds.
    • The ignition voltage is 9.0 volts or greater.
    • The TFT is 20-130°C (68-266°F).
    • The calculated throttle position is greater than 8 percent.
    • The engine torque is greater than 80 N·m (59 lb ft).
    • The vehicle speed greater than 16 km/h (10 mph).
    • Commanded gear is 2nd or greater.
    • The gear ratio is between 0.69-1.97.
    • Solenoid A is enabled.

Conditions for Setting the DTC

P0741

The TCM detects TCC slip greater than 150 RPM for 5 seconds with a TCC commanded ON pressure of 500 kPa or greater. This must occur 6 times during the same ignition cycle.

P0742

The TCM detects the TCC slip is between -20 and +30 RPM for 1.2 seconds or greater when the TCC is commanded OFF 5 times during the same ignition cycle.

Action Taken When the DTC Sets

P0741

    • DTC P0741 is a Type B DTC.
    • The TCM inhibits top gear.
    • The TCM initiates the Hot Mode shift pattern.
    • The TCM commands the TCC OFF.

P0742

    • DTC P0742 is a Type A DTC.
    • The TCM initiates Hot Mode shift pattern.
    • The TCM freezes transmission adaptive functions.
    • The TCM commands the TCC ON.

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

Connector End View Reference

Component Connector End Views

Description and Operation

    •  Transmission General Description
    •  Transmission Component and System Description
    •  Electronic Component 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. Perform the Control Solenoid Valve and Transmission Control Module Assembly Cleaning in order to dislodge debris and free up the valves.
  3. Engine ticking over in Park, verify with a scan tool the transmission ISS/OSS Supply Voltage parameter displays OK.
  4. Engine ticking over in Park, observe the Transmission ISS parameter on the scan tool, while varying the engine speed. The Transmission ISS parameter should vary with engine speed and not drop out.
  5. Note: Perform a scan tool snapshot during the road test.

  6. Perform the Road Test . Verify the transmission operation performs as indicated in the road test instructions.
  7. Review the snapshot transmission data parameters. Verify the engine and transmission data parameters display the correct values in all forward gear ranges.
  8. • Engine Speed
    • Engine Coolant Temperature
    • Transmission ISS
    • Transmission OSS
    • Transmission Fluid Temperature
    • Brake Pedal Switch
    • TCC Pressure Control Solenoid Valve Pressure Command
    • TCC Slip Speed
  9. 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 .

Circuit/System Testing

  1. Perform the 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 .
  2. If not within the specified ranges, refer to Fluid Pressure High or Low .
  3. Ignition OFF, remove the Q8 control solenoid valve assembly. Refer to Control Solenoid Valve and Transmission Control Module Assembly Replacement .
  4. Perform the Control Solenoid Valve and Transmission Control Module Assembly Solenoid Performance Test .
  5. If the Q8 control solenoid valve assembly does not pass the test, replace the Q8 control solenoid valve assembly.
  6. 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.

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 pressurising - 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/Transfer 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

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

       Note: Before replacing the TCM, perform the Control Solenoid Valve and Transmission Control Module Assembly Inspection .

    • Refer to Control Module References for control solenoid valve assembly replacement, set-up, and programming.
    • Perform the Transmission Adaptive Values Learn following all transmission related repairs.
    • Perform the Torque Converter Removal and the Torque Converter Installation .
   


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