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Home >> Lexus >> 2006 >> IS 250 RWD, Standard >> Repair and Diagnosis >> External Pages >> Different car >> Section 12 (Automatic Transmission) >> Automatic Transmission System >> DTC P0781 1-2 Shift (1-2 Shift Valve) >> Typical Malfunction Thresholds

Typical Malfunction Thresholds

WARNING: This page is about a different car, the 2006 Lexus IS 350. However, it is still accessible from the selected car via links, so may be relevant.

Both of the following conditions are met: Condition (A), and Condition (B), (C) or (D)

Malfunction (A) 

TYPICAL ENABLING CONDITIONS

Turbine speed/Output speed (NT/NO) 3.40 or more, and 7.50 or less
(This means actual gear is 1st)

Malfunction (B) 

TYPICAL ENABLING CONDITIONS

Turbine speed/Output speed (NT/NO) 1.28 or more, and 1.53 or less
(This means actual gear is 3rd)

Malfunction (C) 

TYPICAL ENABLING CONDITIONS

Turbine speed - Output speed x 4th gear ratio
(NT - NO x 4th gear ratio)		 1,000 rpm or more

Malfunction (D) 

TYPICAL ENABLING CONDITIONS

Turbine speed - Output speed x 5th gear ratio
(NT - NO x 5th gear ratio)		 1,000 rpm or more
  1. CHECK OTHER DTCS OUTPUT (IN ADDITION TO DTC P0781) 
    1. Connect the OBD II scan tool or the intelligent tester to the DLC3.
    2. Turn the engine switch on (IG) position and push the OBD II scan tool or the intelligent tester main switch ON.
    3. When you use intelligent tester:

      Select the item "DIAGNOSIS / ENHANCED OBD II / DTC INFO / CURRENT CODES".

    4. Read the DTCs using the OBD II scan tool or the intelligent tester.

      Result 

      DATA LIST

      Display (DTC output) Proceed to
      Only "P0781" is output A
      "P0781" and other DTCs B

      HINT:

      If any other codes besides "P0781" 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 

    HINT:

    Performing the ACTIVE TEST using the intelligent tester allows the relay, VSV, actuator and so on to operate without parts removal. Performing the ACTIVE TEST as the first step of troubleshooting is one method to shorten labor time.

    It is possible to display the DATA LIST during the ACTIVE TEST.

    1. Warm up the engine.
    2. Turn the engine switch off.
    3. Connect the intelligent tester together with the CAN VIM (controller area network vehicle interface module) to the DLC3.
    4. Turn the engine switch on (IG) position.
    5. Turn on the tester.
    6. Select the item "DIAGNOSIS / ENHANCED OBD II / ACTIVE TEST / SHIFT".
    7. According to the display on the tester, perform the

      "ACTIVE TEST".

      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 DIAGNOSIS SYSTEM  ).

      DATA LIST

      Item Test Details Diagnostic Note
      SHIFT [Test Details]
      Operate the shift solenoid valve and set the each shift position by yourself.
      [Vehicle Condition]
      • IDL: ON (4th, 5th and 6th)
      • Less than 50 km/h (31 mph)

      [Others]
      • Press "-->" button: Shift up
      • Press "<--" button: Shift down
      		 Possible to check the operation of the shift solenoid valves.

    HINT:

    • This test can be conducted when the vehicle speed is 50 km/h (31 mph) or less.
    • The 4th to 5th and 5th to 6th up-shiftings must be performed with the accelerator pedal released.
    • The 6th to 5th and 5th to 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 POSITIONS

      Tester command gear shift 1st 2nd 3rd 4th 5th 6th
      Actual gear position under malfunction   1st   3rd (1) (1)
      (1) Neutral

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

    NG : 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 (Automatic Transmission Fluid) temperature: 50 to 80°C (122 to 176°F)
    • Be careful to prevent SST hose from interfering with the exhaust pipe.
    • This check must be conducted after checking and adjusting engine.
    • Perform under condition that A/C is OFF.

    HINT:

    Performing the ACTIVE TEST using the intelligent tester allows the relay, VSV, actuator and so on to operate without parts removal. Performing the ACTIVE TEST as the first step of troubleshooting is one method to shorten labor time. It is possible to display the DATA LIST during the ACTIVE TEST.

    1. Turn the engine switch off.
    2. Lift the vehicle up.
    3. Remove the test plug on the transmission case center right side and connect SST.

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

    4. Lower the vehicle.
    5. Fully apply the parking brake and chock the 4 wheels.
    6. Connect the intelligent tester together with the CAN VIM (controller area network vehicle interface module) to the DLC3.
    7. Start the engine.
    8. Warm up the ATF (Automatic Transmission Fluid).
    9. Measure the line pressure when the engine is idling.
    10. Turn on the tester.
    11. Select the item "DIAGNOSIS / ENHANCED OBD II / ACTIVE TEST / SOLENOID (SLT)".
    12. Follow the instructions on the tester and perform the ACTIVE TEST.
    13. Measure the line pressure with SST.
      Fig 1: Measuring Line Pressure With SST
      G04045746Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      DATA LIST

      Item Test Details
      SOLENOID (SLT)(1) [Test Details]
      Operate the shift solenoid SLT and raise the line pressure.
      [Vehicle Condition]
      • Vehicle Stopped.
      • IDL: ON

      HINT:
      OFF: Line pressure up (When the active test of "SOLENOID (SLT)" is performed, the ECM commands the SLT solenoid to turn off).
      ON: No action (normal operation)
      (1) "SOLENOID (SLT)" in the ACTIVE TEST is performed to check the line pressure changes by connecting the SST to the automatic transmission, which is used in the HYDRAULIC TEST  as well.

      HINT:

      The pressure values in ACTIVE TEST and HYDRAULIC TEST are different from each other.

      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 DTC again after conducting the "MONITOR DRIVE PATTERN FOR ECT TEST" (See MONITOR DRIVE PATTERN  ).

      OK: No DTC code 

    NG : REPLACE TRANSMISSION VALVE BODY ASSEMBLY 

    OK : END 

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