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Home >> Lexus >> 2007 >> SC 430 >> Repair and Diagnosis >> Transmission >> Automatic Trans >> Automatic Transaxle >> Automatic Transmission System >> DTC P0729 Gear 6 Incorrect Ratio >> Inspection Procedure
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Inspection Procedure

  1. CHECK OTHER DTCS OUTPUT (IN ADDITION TO DTC P0729) 
    1. Connect the intelligent tester to the CAN VIM. Then connect the CAN VIM to the DLC3.
    2. Turn the ignition switch ON and push the intelligent tester main switch ON.
    3. Enter the following menus: DIAGNOSIS / ENHANCED OBD II / DTC INFO / CURRENT CODES.
    4. Read the DTCs using the intelligent tester.

      Result 

      RESULT REFERENCE CHART

      Display (DTC output) Proceed to
      Only P0729 is output A
      P0729 and other DTCs are output B

      HINT:

      If any other codes besides P0729 are output, perform troubleshooting for those DTCs first.

    B: GO TO DTC CHART 

    A: Go to Next Step 

  2. PERFORM ACTIVE TEST BY INTELLIGENT TESTER (RUNNING TEST) 

    HINT:

    Performing the intelligent tester's ACTIVE TEST allows relay, VSV, actuator and other items to be operated without removing any parts. Performing the ACTIVE TEST early in troubleshooting is one way to save time.

    The DATA LIST can be displayed during the ACTIVE TEST.

    1. Warm up the engine.
    2. Turn the ignition switch OFF.
    3. Connect the intelligent tester to the CAN VIM. Then connect the CAN VIM to the DLC3.
    4. Turn the ignition switch ON.
    5. Turn the intelligent tester ON.
    6. Enter the following menus: DIAGNOSIS / OBD/MOBD / ECT/ ACTIVE TEST.
    7. Perform the ACTIVE TEST using the intelligent tester.

      HINT:

      While driving, the shift position can be forcibly changed with the intelligent tester.

      Comparing the shift position commanded by the ACTIVE TEST with the actual shift position enables you to confirm the problem (see CHECK MODE PROCEDURE  ).

      ECM: 

      TESTER DISPLAY NORMAL CONDITION CHART

      Tester Display Test Part Control Range Diagnostic Note
      SHIFT Operate shift solenoid valve and set each shift position by yourself
      • Press "→" button: Shift up
      • Press "←" button: Shift down
      		 Possible to check operation of shift solenoid valves
      [Vehicle Condition]
      50 km/h (30 mph) or less

      HINT:

      • This test can be conducted when the vehicle speed is 50 km/h (31 mph) or less.
      • The 4th → 5th and 5th → 6th up-shiftings must be performed with the accelerator pedal released.
      • The 6th → 5th and 5th → 4th down-shiftings must be performed with the accelerator pedal released.
      • Do not operate the accelerator pedal for at least 2 seconds after shifting and do not shift successively.
      • The shift position commanded by the ECM is shown in the DATA LIST (SHIFT) display on the intelligent tester.
      • Gear positions in the event of a solenoid valve mechanical problem:
        GEAR POSITION REFERENCE CHART

        Tester command gearshift 1st 2nd 3rd 4th 5th 6th
        Actual gear position under malfunction 1st 2nd 3rd 4th 5th 4th

        OK: Gear position changes in accordance with the tester command. 

    NG: REPAIR OR REPLACE TRANSMISSION VALVE BODY ASSEMBLY 

    OK: Go to Next Step 

  3. PERFORM ACTIVE TEST BY INTELLIGENT TESTER (SHIFT SOLENOID VALVE SLT) 
    NOTE:
    • Perform the test at the normal operating ATF temperature: 50 to 80°C (122 to 176°F).
    • Be careful to prevent SST's hose from interfering with the exhaust pipe.
    • Perform the test with the A/C OFF.

    HINT:

    Performing the intelligent tester's ACTIVE TEST allows relay, VSV, actuator and other items to be operated without removing any parts. Performing the ACTIVE TEST early in troubleshooting is one way to save time. The DATA LIST can be displayed during the ACTIVE TEST.

    1. Remove the test plug on the transmission case center right side and connect SST.

      SST 09992-00095 (09992-00231, 09992-00271) 

    2. Connect the intelligent tester to the CAN VIM. Then connect the CAN VIM to the DLC3.
    3. Start the engine and warm it up.
    4. Measure the line pressure with SST.
    5. Turn the intelligent tester ON.
    6. Enter the following menus: DIAGNOSIS / OBD/MOBD / ECT / ACTIVE TEST.
      Fig 1: Measuring Line Pressure With SST
      G05289558Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    7. Follow the instructions on the tester and perform the ACTIVE TEST.
    8. Measure the line pressure with SST.

      ECM: 

      TESTER DISPLAY NORMAL CONDITION CHART

      Tester Display Test Part Control Range Diagnostic Note
      LINE PRESS UP* Operate the shift solenoid SLT and raise line pressure ON or OFF
      HINT:
      • OFF: Line pressure up (when Active Test "LINE PRESS UP" is performed, ECM commands SLT solenoid to turn OFF)
      • ON: No action (normal operation)
      		 [Vehicle Condition]
      • Vehicle stopped
      • Engine: idling
      HINT:
      • *: LINE PRESS UP in the ACTIVE TEST is performed to check the line pressure change by connecting SST to the automatic transmission, which is used in the HYDRAULIC TEST  .
      • The pressure values in the ACTIVE TEST and HYDRAULIC TEST are different from each other.
      • Normally, the line pressure detected in the ACTIVE TEST is approximately half of the value detected in the HYDRAULIC TEST's stall test.

      OK: The line pressure changes as specified when performing the ACTIVE TEST. 

    NG: REPLACE SHIFT SOLENOID VALVE SLT 

    OK: Go to Next Step 

  4. CLEAR THE DTC AND RUNNING TEST 
    1. Clear the DTC, and check for DTCs again after conducting the "MONITOR DRIVE PATTERN FOR ECT TEST" (see MONITOR DRIVE PATTERN  ).

      OK: No DTC code 

    NG: REPAIR OR REPLACE TRANSMISSION VALVE BODY ASSEMBLY 

    OK: END 

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