AUTOMATIC TRANSAXLE SYSTEM, Diagnostic DTC:P0741

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

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 mechanical problems of the shift solenoid valve (SL), valve body and torque converter.

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

Both conditions are met (2-trip detection logic):


  • Lock-up does not occur when requested.

  • No. 3 ATF pressure switch is on.

  • Shift solenoid valve SL remains closed

  • Transmission valve body assembly is blocked

  • Torque converter assembly

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

  • Line pressure is too low

 Comes on DTC stored

MONITOR DESCRIPTION

Torque converter lock-up is controlled by the TCM based on speed sensor NT, speed sensor NC, engine speed, engine load, engine temperature, vehicle speed, ATF 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 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 turn on the MIL and store the DTC.

Tech Tips

Example:

When the following 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 more than the input turbine speed.)

WIRING DIAGRAM

A01QUNHE01
*1 Shift Solenoid Valve SL
*2 Transmission Valve Body Assembly
*3 Transmission Wire
*4 Automatic Transaxle Assembly

CAUTION / NOTICE / HINT

Note

Perform registration and/or initialization when parts related to the automatic transaxle are replaced.

Click here


  1. ACTIVE TEST

    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. 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 Control shift solenoid valve SLU and SL to set the automatic transaxle to lock-up ON or OFF

      Can be used to check shift solenoid valve SLU and SL operation.

      [Vehicle Condition]

      Vehicle speed: 60 km/h (37 mph) or more

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

    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 abruptly, lock-up is on.

      • When decelerating, slowly release the accelerator pedal, but do not fully release it (fully releasing the pedal will close the throttle valve and lock-up may be turned off).

      A01QRVGE13

PROCEDURE


  1. CHECK DTC 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 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. INSPECT TRANSMISSION WIRE (SHIFT SOLENOID VALVE SL)


    1. Remove the TCM.

    2. A01QOXMC14
      *a

      Component without TCM connected

      (Transmission Wire)

      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. A01QQR4C03
      *1 Shift Solenoid Valve SL

      Remove shift solenoid valve SL.

    2. Apply 12 V battery voltage to the shift solenoid valve and check that the valve moves and makes an operating noise.

      OK
      Measurement Condition Specified Condition

      • Battery positive (+) → Shift solenoid valve SL connector

      • Battery negative (-) → Shift solenoid valve SL body

      		 Valve moves and makes an operating noise
      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 are no foreign objects on any valve.
      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. Remove shift solenoid valve SL.

    2. A01QU3KC03
      *1 Shift Solenoid Valve SL

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      Shift solenoid valve SL connector terminal - Shift solenoid valve SL body 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