AUTOMATIC TRANSAXLE SYSTEM, Diagnostic DTC:P0741

DTC Code DTC Name
P0741 Torque Converter Clutch Solenoid Performance (Shift Solenoid Valve SL)

SYSTEM DESCRIPTION

The TCM uses signals from the throttle position sensor, air-flow meter, turbine (input) speed sensor, intermediate (counter gear) speed sensor and crankshaft position sensor to help determine the engagement timing of the lock-up clutch. The TCM monitors the engagement of the clutch using the turbine (input) speed sensor, intermediate (counter gear) speed sensor and crankshaft position sensor.

Then the TCM compares the engagement condition of the lock-up clutch with the lock-up schedule in the TCM memory to detect shift solenoid valve SL, valve body and torque converter clutch mechanical problems.

DTC No. Detection Item DTC Detection Condition Trouble Area MIL Memory
P0741 Torque Converter Clutch Solenoid Performance (Shift Solenoid Valve SL)

When both of the following are detected (2-trip detection logic):


  • Lock-up does not occur when requested.

  • Transmission fluid pressure switch No. 3 is ON.

  • Shift solenoid valve SL remains closed

  • Valve body is blocked

  • Torque converter assembly

  • Automatic transaxle (clutch, brake or gear etc.)

  • Line pressure is too low

 Comes on DTC stored

MONITOR DESCRIPTION

Torque converter lock-up is controlled by the TCM based on the speed sensor (NT), speed sensor (NC), engine speed, engine load, engine temperature, vehicle speed, transmission fluid temperature, and gear selection. The TCM determines the lock-up status of the torque converter by comparing the engine speed (NE) to the input turbine rpm (NT). The TCM calculates the actual transmission gear by comparing the input turbine rpm (NT) to the counter gear rpm (NC). When conditions are appropriate, the TCM requests "lock-up" by applying control voltage to shift solenoid valve SL. When shift solenoid valve SL is turned on, it applies pressure to the lock-up relay valve and locks the torque converter.

If the TCM detects no lock-up after lock-up has been requested or if it detects lock-up when it is not requested, the TCM interprets this as a fault in shift solenoid valve SL or lock-up system performance. The TCM will illuminate the MIL and store this DTC.

Tech Tips

Example:

When any of the following is met, the system judges it as a malfunction.


CAUTION / NOTICE / HINT

Tech Tips

Using the GTS to perform Active Tests allows relays, VSVs, actuators and other items to be operated without removing any parts. This non-intrusive functional inspection can be very useful because intermittent operation may be discovered before parts or wiring is disturbed. Performing Active Tests early in troubleshooting is one way to save diagnostic time. Data List information can be displayed while performing Active Tests.


  1. PERFORM ACTIVE TEST


    1. Warm up the engine.

    2. Turn the ignition switch off.

    3. Connect the GTS to the DLC3.

    4. Turn the ignition switch to ON.

    5. Turn the GTS on.

    6. Enter the following menus: Powertrain / ECT / Active Test.

    7. According to the display on the GTS, perform the Active Test.


      Powertrain > ECT > Active Test
      Tester Display Measurement Item Control Range Diagnostic Note
      Activate the Lock Up Controls the shift solenoid SLU and SL to set the automatic transaxle to the lock-up condition. ON/OFF

      Can be used to check SLU and SL solenoid operation.

      [Vehicle Condition]


      • Throttle valve opening angle: Less than 20%

      • Vehicle speed:60 km/h (37 mph) or more, and 6th gear

      Powertrain > ECT > Active Test
      Tester Display
      Activate the Lock Up

      Tech Tips


      • This test can be conducted when the vehicle speed is 60 km/h (37 mph) or more.

    8. Lightly depress the accelerator pedal and check that the engine speed does not change abruptly.

      Tech Tips


      • When changing the accelerator pedal opening angle while driving, if the engine speed does not change, lock-up is on.

      • Slowly release, but not fully, the accelerator pedal in order to decelerate. (Fully releasing the pedal will close the throttle valve and lock-up may be turned off.)

      B003ZKME10

PROCEDURE


  1. CHECK OTHER DTCS OUTPUT (IN ADDITION TO DTC P0741)


    1. Connect the GTS to the DLC3.

    2. Turn the ignition switch to ON.

    3. Turn the GTS on.

    4. Enter the following menus: Powertrain / ECT / Trouble Codes.


      Powertrain > ECT > Trouble Codes

    5. Read the DTCs using the GTS.

      Result
      Result Proceed to
      Only DTC P0741 is output A
      P0741 and other DTCs are output B

      Tech Tips

      If any other codes besides P0741 are output, perform the troubleshooting for those DTCs first.


    B

    GO TO DTC CHART Click here

    A

  2. CHECK TRANSMISSION WIRE


    1. A002C2RC11
      *a

      Component without harness connected

      (Transmission Wire)

      Remove the TCM from the transaxle.

    2. Measure the resistance according to the value(s) in the table below.

      Standard Resistance
      Tester Connection Condition Specified Condition
      6 (SL) - Body ground 20°C (68°F) 11 to 15 Ω
      Result
      Proceed to
      OK
      NG

    NG

    INSPECT SHIFT SOLENOID VALVE SL (RESISTANCE) Click here

    OK

  3. INSPECT SHIFT SOLENOID VALVE SL (OPERATION)


    1. A0028KQC02
      *1 Shift Solenoid Valve SL

      Remove shift solenoid valve SL.

    2. Connect a battery positive (+) lead to the terminal of the solenoid valve connector, and a negative (-) lead to the solenoid body. Then check that the valve moves and makes an operating sound.

      OK
      Valve moves and makes an operating sound.
      Result
      Proceed to
      OK
      NG

    NG

    REPLACE SHIFT SOLENOID VALVE SL Click here

    OK

  4. INSPECT TRANSMISSION VALVE BODY ASSEMBLY


    1. Check the transmission valve body assembly.

      Click here

      OK
      There is no foreign matter on each valve and they operate smoothly.
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE TRANSMISSION VALVE BODY ASSEMBLY Click here

    OK

  5. INSPECT TORQUE CONVERTER ASSEMBLY


    1. Check the torque converter assembly.

      Click here

      OK
      The torque converter operates normally.
      Result
      Proceed to
      OK
      NG

    OK

    REPAIR OR REPLACE AUTOMATIC TRANSAXLE ASSEMBLY Click here

    NG

    REPLACE TORQUE CONVERTER ASSEMBLY Click here

  6. INSPECT SHIFT SOLENOID VALVE SL (RESISTANCE)


    1. A002C90C03
      *1 Shift Solenoid Valve SL

      Remove shift solenoid valve SL.

    2. Measure the resistance according to the value(s) in the table below.

      Standard Resistance
      Tester Connection Condition Specified Condition
      Solenoid Connector (SL) - Solenoid Body (SL) 20°C (68°F) 11 to 15 Ω
      Result
      Proceed to
      OK
      NG

    OK

    REPLACE TRANSMISSION WIRE Click here

    NG

    REPLACE SHIFT SOLENOID VALVE SL Click here