Diagnostic Instructions
DTC Descriptor
DTC P0741: Torque Converter Clutch (TCC) System - Stuck Off
Circuit/System Description
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.
Conditions for Running the DTC
• | No Throttle Position (TP) Sensor DTC P0120 |
• | No Transmission Range (TR) Switch DTC’s P0706, P0707, or P0708 |
• | No Transmission Fluid Temperature (TFT) Sensor DTC’s P0711, P0712, or P0713 |
• | No Speed Sensor DTC’s P0717, P0722, P0727 |
• | No Pressure Control (PC) Solenoid DTC’s P0962, P0963, P0966, P0967, P0970, or P0971 |
• | No Shift Solenoid (SS) Control Circuit DTC’s P0973, P0974, P0976, P0977, P0979, P0980, P0982, P0983, P0985, or P0986 |
• | No Transmission Torque Delivered Circuit DTC P2637 |
• | No Communications DTC’s U0100 or U2104 |
• | Engine speed is greater than 400 RPM |
• | Input Speed is less than 3000 RPM |
• | Range equals D, M, or L for 8 seconds |
• | Transmission oil temperature is greater than 20°C |
• | Engine torque is 46 - 240 N·m |
• | The ignition voltage is greater than 10.5 volts |
Conditions for Setting the DTC
Engine speed minus input speed is less than 50 RPM for 12 seconds when the TCC is commanded off - low torque converter slip.
Action Taken When the DTC Sets
The transmission will operate in 5th gear in D or M range, 2nd gear in L range.
Conditions for Clearing the DTC
DTC P0742 is a Type A DTC
Diagnostic Aids
Improper transmission fluid level may cause DTC P0741 to set. Refer to the
Transmission Fluid Check
procedure.
Reference Information
Schematic Reference
Automatic Transmission Controls Schematics
Connector End View Reference
Electrical Information Reference
DTC Type Reference
Scan Tool Reference
Circuit/System Verification
- Ignition ON, observe the DTC information with a scan tool.
- Record Freeze Frame and Failure Records.
- Clear DTC’s.
- Operate the vehicle under the conditions observed in the Failure Records.
- Observe the DTC information with the scan tool. Verify that the DTC does not set.
- 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.
Circuit/System Testing
- Engine ON, apply the parking brake, select P (park) using the Shift Control.
- 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. |
- 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 |
- Perform a line pressure test. Refer to
Line Pressure Check
procedure.
- Remove the Control valve body cover. Refer to
Control Valve Body Cover Removal
procedure.
- Inspect the inside of the control valve body cover for excessive sediment. There should not be excessive sediment.
⇒ | If all conditions test normal, test or replace the transmission. |
- 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 secondary regulator valve |
• | Stuck solenoid relay valve |
• | Stuck TCC lock up PC solenoid valve assembly |
- Verify that the control valve body has been serviced within the past 3 months.
⇒ | If all circuits and components test normal, replace the transmission. |
- If all circuits and components test normal, replace the transmission.
Repair Instructions
Perform the
Diagnostic Repair Verification
after completing the diagnostic procedure.