The transmission control module (TCM) controls the torque converter clutch (TCC) lock up pressure control solenoid valve. The solenoid directs the hydraulic fluid for TCC apply and release. When the TCC is released, the engine is coupled by fluid to the transmission.

Engine speed minus input speed is less than 50 RPM for 12 seconds when the TCC is commanded off - low torque converter slip.

The transmission will operate in 5th gear in D or M range, 2nd gear in L range.

DTC P0742 is a Type A DTC

Improper transmission fluid level may cause DTC P0741 to set. Refer to the Transmission Fluid Check procedure.

Schematic Reference

Automatic Transmission Controls Schematics

Connector End View Reference

Electrical Information Reference

DTC Type Reference

Scan Tool Reference

Control Module References for scan information.

1. Ignition ON, observe the DTC information with a scan tool.
2. Record Freeze Frame and Failure Records.
3. Clear DTC’s.
4. Operate the vehicle under the conditions observed in the Failure Records.
5. Observe the DTC information with the scan tool. Verify that the DTC does not set.
6. Operate the vehicle in D (drive). Using a scan tool, observe the TCC Slip Speed parameter in 3rd, 4th, and 5th gear while the TCC PC Sol. Ref. Current parameter is more than 1000 mA. The TCC Slip Speed parameter should not be more than 100 RPM.

1. Engine ON, apply the parking brake, select P (park) using the Shift Control.
2. Observe the scan tool Transmission ISS parameter. The reading should be within 400-800 RPM.

⇒	If the ISS parameter is not within the specified range, test or replace the Transmission Input Speed Sensor (ISS). Refer to the Input Speed Sensor Replacement procedure.

3. Operate the vehicle in 3rd gear. Observe Gear Ratio parameter on the scan tool. The Gear Ratio parameter should not equal 2.84:1.

⇒	If the Gear Ratio parameter equals 2.84:1 while in 3rd gear, test or replace the:

•	3-4, 4-5 shift solenoid valve assembly

•	U1 shift valve

•	Refer to the Control Valve Body Assembly Disassemble procedure.

⇒	If all conditions test normal, test or replace the control valve body assembly. Refer to Control Valve Body Replacement procedure.

4. Perform a line pressure test. Refer to Line Pressure Check procedure.
5. Remove the Control valve body cover. Refer to Control Valve Body Cover Removal procedure.
6. Inspect the inside of the control valve body cover for excessive sediment. There should not be excessive sediment.

⇒	If excessive sediment is found inspect and replace as necessary the Torque converter assembly, Input shaft, and Fluid pump stator shaft assembly. Refer to Torque Converter Assembly Removal , Forward and Direct Clutch Assembly Assemble and Transmission Fluid Pump Cleaning and Inspection procedures.

⇒	If all conditions test normal, test or replace the transmission.

7. Inspect the control valve body assembly for the following conditions. The conditions should not be found.

•	Stuck lock up relay valve

•	Stuck lock up control valve

•	Stuck TCC check valve

•	Stuck secondary regulator valve

•	Stuck solenoid relay valve

•	Stuck TCC lock up PC solenoid valve assembly

•	Refer to Control Valve Rear Body Disassemble and Control Valve Body Disassemble - Middle .

⇒	If any of the above conditions are found, replace the valve body assembly. Refer to Control Valve Body Replacement procedure.

8. Verify that the control valve body has been serviced within the past 3 months.

⇒	If the control valve body has not been serviced, replace the control valve body assembly. Refer to Control Valve Body Replacement procedure.

⇒	If all circuits and components test normal, replace the transmission.

9. If all circuits and components test normal, replace the transmission.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.