P0742
DTC P0742, P0752, or P0757
Diagnostic Instructions
* Perform the Diagnostic System Check - Vehicle (Initial Inspection and Diagnostic Overview) prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis (Initial Inspection and Diagnostic Overview) for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions (Initial Inspection and Diagnostic Overview) provide an overview of each diagnostic category.
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
Typical Scan Tool Data
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 (Shift Solenoid Valve State and Gear Ratio).
Conditions for Running the DTC
P0742
* No TP sensor DTC P0120 or P0220.
* No ISS DTC P0716 or P0717.
* No OSS DTC P0722 or P0723.
* No TCC system stuck ON DTC P0742.
* The engine speed is greater than 500 RPM for 5 seconds.
* The transmission fluid temperature (TFT) is between 20-130°C (68-266°F).
* No TCC system stuck OFF DTC P0741.
* The calc. throttle position is between 8-90 percent.
* The TCC PWM solenoid valve is commanded OFF.
* The gear ratio is between 0.66:1-1.68:1.
* The engine torque is greater than 50 Nm (37 lb ft).
* The vehicle speed is 16 km/h (10 mph) or greater.
P0752
* No TP sensor DTC P0120 or P0220.
* No ISS DTC P0716 or P0717.
* No OSS DTC P0722 or P0723.
* No TCC system stuck ON DTC P0742.
* The engine speed is greater than 500 RPM for 5 seconds.
* The TFT is between 20-130°C (68-266°F).
* No TCC system stuck ON DTC P0742.
* No 1-2 SS valve electrical DTC P0973 or P0974.
* No 2-3 SS valve electrical DTC P0976 or P0977.
* The calc. throttle position is 8 percent or greater.
* The transmission ISS is 150 RPM or greater.
* The transmission OSS is 160 RPM or greater.
* The engine torque is greater than 50 Nm (37 lb ft).
* The time since the last gear change is 1.5 seconds.
P0757
* No TP sensor DTC P0120 or P0220.
* No ISS DTC P0716 or P0717.
* No OSS DTC P0722 or P0723.
* No TCC system stuck ON DTC P0742.
* The engine speed is greater than 500 RPM for 5 seconds.
* The transmission fluid temperature is between 20-130°C (68-266°F).
* No TCC system stuck ON DTC P0742.
* No 1-2 SS valve electrical DTC P0973 or P0974.
* No 2-3 SS valve electrical DTC P0976 or P0977.
* The calc. throttle position is 8 percent or greater.
* The transmission ISS is 150 RPM or greater.
* The transmission OSS is 160 RPM or greater.
* The engine torque is 40 Nm (29 lb ft) or greater when 3rd gear is commanded.
* The time since the last gear change is 1.5 seconds.
Conditions for Setting the DTC
P0742
* The TCC slip speed is between -20 and +40 RPM for 6 seconds, 3 times during the same ignition cycle (3.5L and 3.9L).
* The TCC slip speed is between -20 and +40 RPM for 5 seconds, 3 times during the same ignition cycle (5.3L).
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.
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
P0742
* DTC P0742 and P0752 are type B DTCs.
* DTC P0757 is a type A DTC.
* The TCM commands maximum line pressure.
* The TCM freezes transmission adaptive functions.
* The TCM commands the TCC ON at maximum capacity.
P0752
* DTC P0742 and P0752 are type B DTCs.
* DTC P0757 is a type A DTC.
* The TCM commands maximum line pressure.
* The TCM freezes transmission adaptive functions.
* The TCM inhibits 3-2 downshifts when the vehicle speed is greater than 52 km/h (32 mph).
P0757
* DTC P0742 and P0752 are type B DTCs.
* DTC P0757 is a type A DTC.
* The TCM commands maximum line pressure.
* The TCM freezes transmission adaptive functions.
* The TCM inhibits 4th gear.
Conditions for Clearing the DTC
* DTC P0742 and P0752 are type B DTCs.
* DTC P0757 is a type A 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:
* Fluid contamination
* Plugged fluid circuits
* Restricted fluid circuits
Reference Information
Schematic Reference
Automatic Transmission Controls Schematics (Electrical Diagrams)
Connector End View Reference
Component Connector End Views (Connector Views)
Electrical Information Reference
* Circuit Testing (Component Tests and General Diagnostics)
* Connector Repairs (Component Tests and General Diagnostics)
* Testing for Intermittent Conditions and Poor Connections (Component Tests and General Diagnostics)
* Wiring Repairs (Component Tests and General Diagnostics)
DTC Type Reference
Powertrain Diagnostic Trouble Code (DTC) Type Definitions (Diagnostic Trouble Code Descriptions)
Scan Tool Reference
Control Module References (Programming and Relearning) for scan tool information
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 (Testing and Inspection).
• 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:
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 (Overhaul).
* The TCC blowoff valve or spring for damage or not seating-Refer to Case Assembly Inspection (Overhaul).
* Turbine shaft seals for leaks-Refer to Torque Converter Assembly Removal (Overhaul).
* Pump shaft seal for leaks-Refer to Oil Pump Drive Shaft Assemble (Overhaul).
* Spacer plate gaskets torn or leaking-Refer to Control Valve Body and Spacer Plate Assemble (Overhaul).
* Pressure regulator valve stuck-Refer to Control Valve Body Disassemble (Overhaul).
* Abnormally high or low line pressure-Refer to Line Pressure Check (Line Pressure Check Procedure).
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 (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:
P0752
* The 1-2 shift solenoid mechanically stuck ON
* A stuck or binding 1-2 shift valve
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 (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 (Verification Tests) after completing the diagnostic procedure.
* Shift Solenoid Leak Test (Shift Solenoid Leak Test)
* 1-2 Shift Solenoid Valve Replacement (1-2 Shift Solenoid Valve Replacement)
* 2-3 Shift Solenoid Valve Replacement (2-3 Shift Solenoid Valve Replacement)
* Torque Converter Clutch Pulse Width Modulation Solenoid Valve Replacement (Torque Converter Clutch Pulse Width Modulation Solenoid Valve Replacement)
* Control Valve Body Disassemble (Overhaul)
* Case Cover Removal (Overhaul)
* Case Cover and Gaskets Assemble (Overhaul)
* Case Cover Components Disassemble (Overhaul)