Diagnostic Instructions

DTC Descriptors

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

DTC P0752: 1-2 Shift Solenoid (SS) Valve Performance - No Second or Third Gear

DTC P0757: 2-3 Shift Solenoid (SS) Valve Performance - No Third or Fourth Gear

Diagnostic Fault Information

Circuit	Short to Ground	Open/High Resistance	Short to Voltage	Hydraulic Performance
1-2 SS Valve Control	P0973	P0973	P0974	P0751, P0752
2-3 SS Valve Control	P0976	P0976	P0977	P0756, P0757
TCC PWM Valve Control	P2764	P2764	P2763	P0741, P0742

Typical Scan Tool Data

Circuit	Normal	Short to Ground	Open/High Resistance	Short to Voltage
Operating Conditions: Engine running, normal operating temperature Parameter Normal Range: Indeterminate
1-2 Sol. CKT Status	Indeterminate	Short to GND	Open	Short to Volts
2-3 Sol. CKT Status	Indeterminate	Short to GND	Open	Short to Volts
TCC Duty Cycle CKT Status	Indeterminate	Short to GND	Open	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 normally allows 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. The 1-2 shift solenoid (SS) valve and the 2-3 SS valve are supplied with fused ignition voltage. The ground path is controlled by the TCM. When the TCM commands the solenoid OFF, a ground path is not provided and the filtered line pressure that is fed to the solenoid is exhausted. When the TCM commands the solenoid ON, a ground path is provided and the exhaust port is blocked, stopping the exhaust of line pressure. The TCM identifies a 1-2 SS valve or a 2-3 SS valve condition by monitoring the commanded gear versus gear ratio. Refer to Shift Solenoid Valve State and Gear Ratio .

Conditions for Running the DTC

DTC P0742

DTC P0752

DTC P0757

Conditions for Setting the DTC

DTC P0742

DTC P0752

The following conditions both occur twice in 1 trip:

Condition 1

The TCM commands 2nd gear and the gear ratio indicated 1st gear, 2.78:1-3.09:1 for 2 seconds.

Condition 2

The TCM commands 3rd gear and the gear ratio indicates 4th gear, 0.67:1-0.74:1, for 2 seconds.

DTC P0757

The following conditions both occur twice in 1 trip:

Condition 1

The TCM commands 3rd gear and the gear ratio indicates 2nd gear, 1.48:1-1.65:1, for 2 seconds.

Condition 2

The TCM commands 4th gear and the gear ratio indicates 1st gear, 1.65:1-3.09:1, for 2 seconds.

Action Taken When the DTC Sets

DTC P0742

DTC P0752

DTC P0757

Conditions for Clearing the DTC

Diagnostic Aids

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

Reference Information

Schematic Reference

Automatic Transmission Controls Schematics

Connector End View Reference

Electrical Information Reference

Scan Tool Reference

DTC Type Reference

Circuit/System Verification

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. Perform the Transmission Fluid Check .

⇒	Correct the transmission fluid level if the fluid is not at the proper level.

2. Using the scan tool, clear the DTC. If DTC P0742 was set, operate the vehicle greater than 72 km/h (45 mph) with the Calc. Throttle Position between 8-90 percent and use the scan tool to command the TCC OFF. Observe the TCC Slip Speed parameter on the scan tool. The TCC Slip Speed should be greater than 60 RPM.

⇒	If the TCC Slip Speed is less than 60 RPM, inspect the following components and repair or replace as necessary:

DTC P0742

•	The TCC control valve stuck in the apply position

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

•	The TCC fluid circuits leaking

•	Refer to Control Valve Body Disassemble .

•	The TCC blowoff valve or spring for damage or not seating

•	Refer to Case Assembly Inspection .

•	Turbine shaft seals for leaks

•	Refer to Torque Converter Assembly Removal .

•	Pump shaft seal for leaks

•	Refer to Oil Pump Drive Shaft Assemble .

•	Spacer plate gaskets torn or leaking

•	Refer to Control Valve Body and Spacer Plate Assemble .

•	Pressure regulator valve stuck

•	Refer to Control Valve Body Disassemble .

•	Abnormally high or low line pressure

•	Refer to Line Pressure Check .

3. Using the scan tool, clear the DTC. If DTC P0752 or P0757 is set, drive the vehicle to ensure the TCM commands 1st, 2nd, 3rd, and 4th gears. The ratios should match the commanded gear for all gears. Refer to Shift Solenoid Valve State and Gear Ratio .

⇒	If the gear ratios do not match the commanded gear, inspect the following and repair or replace as necessary:

DTC P0752

•	The 1-2 shift solenoid mechanically stuck ON

•	A stuck or binding 1-2 shift valve

DTC P0757

•	The 2-3 shift solenoid mechanically stuck ON

•	A stuck or binding 2-3 shift valve

Component Testing

1. Perform the 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. The resistance should be between 10-15 ohms for the TCC PWM solenoid.

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

Repair Instructions

Perform the Diagnostic Repair Verification after completing the repair.