4L60-E/4L65-E/4L70-E - Automatic Transmission

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) solenoid valve is a normally-open exhaust valve that is used with the torque converter clutch pulse width modulation (TCC PWM) solenoid valve in order to control fluid acting on the converter clutch apply valve. The TCC solenoid valve attaches to the transmission case assembly extending into the pump cover. When grounded, energized, by the transmission control module (TCM), the TCC solenoid valve stops converter signal oil from exhausting. This causes converter signal oil pressure to increase and move the converter clutch apply valve against spring force and into the apply position. In this position, release fluid is open to an exhaust port and converter feed fluid fills the apply fluid circuit. The converter feed fluid applies the TCC. When the TCM no longer provides a ground path, the TCC solenoid valve de-energizes and apply fluid exhausts, releasing the TCC.

Conditions for Running the DTC

P0741

* No input speed sensor (ISS) DTCs P0716 or P0717.

* No output speed sensor (OSS) DTCs P0722 or P0723.

* No TCC DTCs P0742.

* No TCC PWM DTCs P2763 or P2764.

* Ignition voltage between 8-18 volts.

* The engine torque is greater than 50 Nm (37 lb ft).

* The throttle position is 8-90 percent.

* The transmission fluid temperature is 20-130°C (68-266°F).

* The gear ratio is within the following ranges:

- 1.54:1-1.71:1 - 2nd gear

- 0.95:1-1.05:1 - 3rd gear

- 0.66:1-0.73:1 - 4th gear

* The TCC is commanded ON for 0.1 second.

* The TCC duty cycle is greater than 65 percent.

P0742

* No ISS DTCs P0716 or P0717.

* No OSS DTCs P0722 or P0723.

* No TCC DTC P0741.

* No TCC PWM DTCs P2763 or P2764.

* Ignition voltage between 8-18 volts.

* The transmission fluid temperature is 20-130°C (68-266°F).

* The engine speed is 500-6500 RPM.

* The engine torque is at least 80 Nm (59 lb ft).

* The throttle position is 8-90 percent.

* The commanded gear is not 1st gear and the gear ratio is 0.66:1-1.71:1.

* The vehicle speed is greater than 16 km/h (10 mph).

* TCC is commanded OFF.

Conditions for Setting the DTC

P0741

The TCM commands TCC ON, and the TCC slip is 150 RPM or greater for 5 seconds, 2 times during the same ignition.

P0742

The TCM commands TCC ON, and the TCC slip is between -20 RPM and 30 RPM for 6 seconds, 3 times during the same ignition.

Action Taken When the DTC Sets

P0741

* DTC P0741 is a Type B DTC.

* The TCM commands maximum line pressure.

* The TCM commands TCC OFF.

* The TCM inhibits 4th gear if the transmission is in Hot Mode.

* The TCM freezes transmission adaptive functions.

P0742

* DTC P0742 is a Type B DTC.

* The TCM commands maximum line pressure.

* The TCM commands TCC ON.

* The TCM freezes transmission adaptive functions.

Conditions for Clearing the DTC

DTCs P0741 and P0742 are Type B DTCs.

Diagnostic Aids

If the DTC is cleared, then will not reset when the vehicle is driven, some of the following conditions may exist:

* Fluid contamination

* Plugged fluid circuits

* Restricted fluid circuits

* Inspect transmission fluid lines to radiator. Lines may be pinched, plugged or twisted.

* Refer to Shift Solenoid Valve State and Gear Ratio 4L60-E/4L65-E/4L70-E - Automatic Transmission.

* Internal damage to the torque converter may prevent TCC application.

Reference Information

Schematic Reference

Automatic Transmission Controls Schematics 4L60-E/4L65-E/4L70-E - Automatic Transmission

Connector End View Reference

Component Connector End Views 1-2 Shift Solenoid (SS) Valve (M30)

Description and Operation

Transmission General Information Transmission General Information

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

Transmission Control Module Scan Tool Information (4L60-E) 4L60-E - Automatic TransmissionTransmission Control Module Scan Tool Information (6L45/6L50/6L80/6L90) 6L45/6L50/6L80/6L90 - Automatic Transmission

Circuit/System Verification

1. Ensure that the transmission fluid level is at the proper level by performing the Transmission Fluid Level and Condition Check 4L60-E/4L65-E/4L70-E - Automatic Transmission.

2. Start and idle the engine. Using the scan tool output controls command the affected solenoid ON and OFF. Observing the CKT Status parameter on the scan tool for the affected solenoid, ensure the parameter displays OK.

Circuit/System Testing

1. Operate the vehicle at 72 km/h (45 mph) with the throttle position at 20 percent. Command TCC ON with a scan tool while observing the scan tool TCC Slip Speed parameter.

• If the TCC Slip Speed is 150 RPM for 5 seconds, inspect the following conditions and repair/replace as necessary:

* The cooling system for plugging and the cooler lines for being pinched. Refer to Transmission Fluid Cooler Flushing and Flow Test (J 45096) Transmission Fluid Cooler Flushing and Flow Test (J 45096).

* The TCC control valve, the TCC regulator apply valve, the pressure control solenoid regulator valve or the TCC PWM solenoid valve for sticking and O-ring seals for leaks. Refer to Control Valve Body Disassemble Control Valve Body Disassemble.

* The TCC blowoff valve or spring for damage or not seating. Refer to Case Assembly Inspection Case Assembly Inspection.

* The TCC signal orifice in the spacer plate plugged, the #1 check ball missing or leaking and the spacer plate gaskets for being torn or leaking. Refer to Control Valve Body Assemble Control Valve Body Assemble.

* The turbine shaft seals for leaks. Refer to Torque Converter Assembly Removal Torque Converter Assembly Removal.

* The torque converter clutch. Refer to Torque Converter Diagnosis Torque Converter Diagnosis.

* TCC PWM solenoid valve for a damaged exhaust orifice.

* TCC regulator apply valve stuck in the OFF position.

* TCC Sol valve stuck in the OFF position or leaking.

* TCC enable valve stuck in the OFF position.

* Misaligned damaged or leaking valve body gasket.

* TCC for being mechanically stuck OFF.

* Inspect the forward clutch input housing assembly for the input shaft fluid seal ring leaking or worn.

* Refer to Symptoms - Automatic Transmission Symptoms - Automatic Transmission NO TCC apply.

• If the TCC Slip Speed is between -20 and 40 RPM for greater than 5 seconds, inspect for the following conditions and repair/replace as necessary:

- The TCC PWM solenoid valve stuck, exhaust restricted, or faulty internal O-ring.

- The TCC fluid circuits leaking. Refer to Control Valve Body Disassemble Control Valve Body Disassemble.

- Turbine shaft seals for leaks. Refer to Torque Converter Assembly Removal Torque Converter Assembly Removal.

- Pump shaft seal for leaks. Refer to Oil Pump Body Assemble Oil Pump Body Assemble.

- Spacer plate gaskets torn or leaking. Refer to Control Valve Body Assemble Control Valve Body Assemble.

- Pressure regulator apply valve stuck. Refer to Control Valve Body Disassemble Control Valve Body Disassemble.

- Abnormally high or low line pressure. Refer to Line Pressure Check Line Pressure Check.

- Clogged exhaust orifice in the TCC solenoid valve.

- Converter clutch apply valve stuck in the apply position.

- Misaligned or damaged valve body gasket.

- Restricted release passage.

- Restricted transmission cooler line.

2. Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.

Component Testing

1. Perform the Shift Solenoid Leak Test Shift Solenoid Leak Test.

• If the solenoid fails the shift solenoid leak test, replace the affected solenoid.

2. Disconnect the wiring harness connector from the affected solenoid. Measure the resistance for the affected solenoid. The resistance should be between 19-31 ohms for the 1-2 SS and the 2-3 SS.

• If the resistance is not within the specified range, replace the affected solenoid.

Repair Instructions

Perform the Diagnostic Repair Verification Verification Tests after completing the repair.