СИСТЕМА АВТОМАТИЧЕСКОЙ ТРАНСМИССИИ, Diagnostic DTC:P0741, P2757

DTC Code DTC Name
P0741 Torque Converter Clutch Solenoid Performance (Shift Solenoid Valve SL)
P2757 Torque Converter Clutch Pressure Control Solenoid Performance (Shift Solenoid Valve SLU)

DESCRIPTION

By turning the shift solenoid valve SL ON or OFF, the TCM controls the fluid pressure to the lock-up relay valve, turning the lock-up ON or OFF.

DTC No.

DTC Detection Condition


  1. Diagnosis Condition

  2. Malfunction Status

  3. Malfunction Time

  4. Other

 Trouble Area
P0741

  1. ECT is 40°C (104°F) or higher, ATF temperature is -10°C (14°F) or higher, and vehicle is driven with the shift lever in D (no malfunctions are detected in shift solenoid valve SL1, 2, 3, 4 and 5, SR, SLU, SL, transmission revolution sensors (SP2, NT), engine coolant temperature sensor, oil temperature sensor, knock control sensor, electronic throttle, or CAN2)

  2. During lock-up request, the engine speed and turbine speed slip amount is 70 rpm or more

  3. 2 seconds or more per trip

  4. 2 trip detection logic

  • Shift solenoid valve SL

  • Shift solenoid valve SLU

  • Valve body assembly

  • Torque converter assembly

  • Automatic transmission assembly
P2757

  1. ECT is 40°C (104°F) or higher, ATF temperature is -10°C (14°F) or higher, and the vehicle is driven with the shift lever in D (no malfunctions are detected in shift solenoid valve SL1, 2, 3, 4 and 5, SR, SLU, SL, transmission revolution sensors (SP2, NT), engine coolant temperature sensor, oil temperature sensor, knock control sensor, electronic throttle, or CAN2)

  2. During lock-up request, the engine speed and turbine speed slip amount is 70 rpm or more

  3. 2 seconds or more per trip

  4. 2 trip detection logic

  • Shift solenoid valve SL

  • Shift solenoid valve SLU

  • Valve body assembly

  • Torque converter assembly

  • Automatic transmission assembly

MONITOR DESCRIPTION

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

If the TCM detects no lock-up after lock-up has been requested, the TCM interprets this as a fault in the shift solenoid valve SL or SLU. The TCM will turn on the MIL and store the DTC.

Tech Tips

Example:

When the following condition is met, the system judges it to be a malfunction.

There is a difference in rotation (speed) between the input side (engine speed) and output side (input turbine speed) of the torque converter when the TCM commands lock-up.

(Engine speed is at least 70 rpm greater than the input turbine speed.)

INSPECTION PROCEDURE

Note

Perform registration and/or initialization when parts related to the automatic transmission are replaced Click here.

PROCEDURE


  1. CHECK DTC OUTPUT (IN ADDITION TO DTC P0741 AND P2757)


    1. Connect the GTS to the DLC3.

    2. Turn the engine switch on (IG).

    3. Turn the GTS on.

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

    5. Read the DTCs using the GTS.

      Result
      Result Proceed to
      Only DTCs P0741 and P2757 are output A
      P0741, P2757 and other DTCs are output B

      Tech Tips

      If a solenoid related or oil pressure switch related DTC is output, troubleshoot that DTC first.


    B

    GO TO DTC CHART Click here

    A

  2. INSPECT SHIFT SOLENOID VALVE SL


    1. A01FHG3E01
      Text in Illustration
      *1 Shift Solenoid Valve SL

      Remove the shift solenoid valve SL Click here.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      Shift solenoid SL connector - Shift solenoid SL body 20°C (68°F) 11 to 15 Ω

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

      OK
      Valve moves and makes an operating sound.

    NG

    REPLACE SHIFT SOLENOID VALVE SL Click here

    OK

  3. INSPECT SHIFT SOLENOID VALVE SLU


    1. A01FI7WE21
      Text in Illustration
      *1 Shift Solenoid Valve SLU

      Remove the shift solenoid valve SLU Click here.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      Terminal 1 of the shift solenoid valve SLU - Terminal 2 20°C (68°F) 5.0 to 5.6 Ω

    3. Connect a positive (+) battery lead with a 21 W bulb to terminal 2 and a negative (-) battery lead to terminal 1 of the solenoid valve connector. Then check that the valve moves and makes an operating sound.

      OK
      Valve moves and makes an operating sound.

    NG

    REPLACE SHIFT SOLENOID VALVE SLU 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.

    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.

    NG

    REPLACE TORQUE CONVERTER ASSEMBLY Click here

    OK

    REPAIR OR REPLACE AUTOMATIC TRANSMISSION ASSEMBLY Click here