СИСТЕМА АВТОМАТИЧЕСКОЙ ТРАНСМИССИИ (для моделей с 3ZR-FE), Diagnostic DTC:P0741

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

DESCRIPTION

The ECM uses the signals from the throttle position sensor, air-flow meter, turbine (input) speed sensor, intermediate (counter) shaft speed sensor and crankshaft position sensor to monitor the engagement condition of the lock-up clutch. Then the ECM compares the engagement conditions of the lock-up clutch with the lock-up schedule in the ECM memory to detect mechanical problems of shift solenoid valve DSL, the valve body and torque converter clutch.

DTC Code DTC Detection Condition Trouble Area
P0741 Lock-up does not occur when driving in the lock-up range, or lock-up remains ON in the lock-up OFF range (2 trip detection logic).

  • Shift solenoid valve DSL remains open or closed

  • Valve body is blocked

  • Shift solenoid valve DSL

  • Torque converter clutch

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

  • Line pressure is too low

MONITOR DESCRIPTION

Torque converter clutch lock-up is controlled by the ECM based on the speed sensor (NT) signal, speed sensor (NC) signal, engine speed, engine load, engine temperature, vehicle speed, transaxle temperature and gear selection.

The ECM determines the lock-up status of the torque converter clutch by comparing the engine speed (NE) to the input turbine rpm (NT). The ECM calculates the actual transaxle gear by comparing input turbine rpm control voltage to counter gear rpm (NC). When conditions are appropriate, the ECM requests lock-up by applying control voltage to shift solenoid valve DSL. When shift solenoid valve DSL is turned on, it applies pressure to the lock-up relay valve and locks the torque converter clutch.

If the ECM detects no lock-up after lock-up has been requested or if it detects lock-up when lock-up is not requested, the ECM interprets this as a fault in shift solenoid valve DSL or lock-up system performance.

Then the ECM illuminates the MIL and stores the DTC.

Example:

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

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

    (Engine speed is at least 100 rpm greater than input turbine speed.)

  2. There is no difference in rotation between the input side (engine speed) and output side (input turbine speed) of the torque converter clutch when the ECM commands lock-up OFF.

    (The difference between engine speed and input turbine speed is less than 35 rpm.)

WIRING DIAGRAM

A005W2PE57

INSPECTION PROCEDURE

  1. ACTIVE TEST

    Tech Tips

    Using the intelligent tester 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 intelligent tester to the DLC3.

    4. Turn the ignition switch to ON.

    5. Turn the intelligent tester on.

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

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

      Engine and ECT
      Tester Display Test Part Control Range Diagnostic Note
      Activate the Lock Up Control shift solenoid valve DSL to set automatic transaxle to lock-up condition ON or OFF

      It is possible to check the shift solenoid valve DSL operation.

      [Vehicle Condition]

      • The throttle valve opening amount is less than 35%.

      • The vehicle speed is 60 km/h (37 mph) or more.

      Tech Tips

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

      • Perform this test while driving in 3rd or 4th gear.

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

      A005WD2E01

      Tech Tips

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

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

PROCEDURE

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

    1. Connect the intelligent tester to the DLC3.

    2. Turn the ignition switch to ON.

    3. Turn the intelligent tester on.

    4. Enter the following menus: Powertrain / Engine and ECT / DTC.

    5. Read the DTCs using the tester.

      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 troubleshooting for those DTCs first.

    B

    GO TO DTC CHART Click here

    A

  2. INSPECT TRANSMISSION WIRE (SHIFT SOLENOID VALVE DSL)

    1. Disconnect the B19 transmission wire connector.

      A005WDGE02

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      3 (DSL) - Body ground 20°C (68°F) 11 to 13 Ω
      Text in Illustration
      *1

      Component without harness connected

      (Transmission Wire)
    NG

    INSPECT SHIFT SOLENOID VALVE DSL Click here

    OK

  3. CHECK HARNESS AND CONNECTOR (TRANSMISSION WIRE - ECM)

    1. Disconnect the B39 ECM connector.

      A005S8YE04

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      B39-56 (DSL) - Body ground 20°C (68°F) 11 to 13 Ω
      Text in Illustration
      *1

      Front view of wire harness connector

      (to ECM)
    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

    REPLACE ECM Click here

  4. INSPECT SHIFT SOLENOID VALVE DSL

    1. Remove shift solenoid valve DSL.

      A005SVCE01

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      Shift solenoid valve DSL connector terminal - Shift solenoid valve DSL body 20°C (68°F) 11 to 13 Ω

    3. 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 DSL connector

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

      		 Valve moves and makes an operating noise
      Text in Illustration
      *1

      Component without harness connected

      (Shift Solenoid Valve DSL)
    NG

    REPLACE SHIFT SOLENOID VALVE DSL Click here

    OK

  5. CHECK TRANSMISSION WIRE

    1. Check the transmission wire.

      OK
      The connectors and pins are securely installed. There is no open or short in the wire harness.
    NG

    REPAIR OR REPLACE TRANSMISSION WIRE Click here

    OK

  6. INSPECT TRANSMISSION VALVE BODY ASSEMBLY

    1. Check the transmission valve body assembly Click here.

      OK
      There are no foreign objects on any valve.
    NG

    REPAIR OR REPLACE TRANSMISSION VALVE BODY ASSEMBLY Click here

    OK

  7. INSPECT TORQUE CONVERTER CLUTCH ASSEMBLY

    1. Check the torque converter clutch assembly Click here.

      OK
      The torque converter clutch operates normally.
    NG

    REPLACE TORQUE CONVERTER CLUTCH ASSEMBLY Click here

    OK

    REPAIR AUTOMATIC TRANSAXLE ASSEMBLY Click here