Diagnostic Instructions

DTC Descriptors

DTC P0741:  Torque Converter Clutch (TCC) System - Stuck Off

DTC P0742:  Torque Converter Clutch (TCC) System - Stuck On

Diagnostic Fault Information

Hydraulic Circuit	Short to Ground	Open/High Resistance	Short to Voltage	Signal Performance
1-2 SS Valve	--	--	--	P0751, P0752
2-3 SS Valve	--	--	--	P0756, P0757
TCC PWM Valve	--	--	--	P0741, P0742

Typical Scan Tool Data

Torque Converter Clutch (TCC) System Parameter Data

Circuit	Normal	Short to Ground	Open/High Resistance	Short to Voltage
Operating Conditions: Engine running, normal operating temperature Parameter Normal Range: OK
1-2 Sol. CKT Status	OK	Open/Short to GND	Open/Short to GND	Short to Volts
2-3 Sol. CKT Status	OK	Open/Short to GND	Open/Short to GND	Short to Volts
TCC Duty Cycle CKT Status	OK	Open/Short to GND	Open/Short to GND	Short to Volts

Circuit/System Description

The transmission control module (TCM) controls the torque converter clutch pulse width modulation (TCC PWM) solenoid valve. The solenoid controls the hydraulic fluid for TCC apply and release. When the TCC is fully applied, the engine is coupled directly to the transmission through the TCC. The TCC used is an electronically controlled capacity clutch (ECCC). The TCM will normally allow a small amount of slip to occur with the ECCC. When the TCC is engaged, TCC slip speed is maintained at approximately 20-50 RPM.

Conditions for Running the DTC

P0741

P0742

Conditions for Setting the DTC

P0741

The TCC slip speed is 150 RPM or greater for 8 seconds 2 times during the same ignition cycle.

P0742

The TCC slip speed is between -20 and 40 RPM for 6 seconds 3 times during the same ignition cycle.

Action Taken When the DTC Sets

P0741

P0742

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:

Reference Information

Schematic Reference

Automatic Transmission Controls Schematics

Connector End View Reference

Component Connector End Views

Electrical Information Reference

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 Check to verify correct fluid level and condition. The transmission fluid level should be within the crosshatch band and the transmission fluid should be red or dark brown.

⇒	If the transmission fluid is low or discolored, refer to Automatic Transmission Fluid Filter and Seal Replacement .

2. Operate the vehicle at 72 km/h (45 mph) with the throttle position at 20 percent. Command the TCC ON with a scan tool while observing the scan tool TCC Slip Speed parameter. The reading should be below 175 RPM.

⇒	If the TCC Slip Speed is greater than 175 RPM for greater than 5 seconds, inspect for the following conditions and repair/replace as necessary:

•	TCC PWM solenoid valve mechanically stuck OFF leaking

•	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

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

⇒	If the TCC Slip Speed is between 150-1,500 RPM for greater than 5 seconds, inspect for the following conditions and repair/replace as necessary:

•	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

3. 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.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the repair.