ELECTRONIC CONTROLLED AUTOMATIC TRANSMISSION SYSTEM MECHANICAL SYSTEM TESTS


  1. PERFORM MECHANICAL SYSTEM TESTS


    1. Measure the stall speed.

      The object of this test is to check the overall performance of the transmission and engine by measuring the stall speeds in the D position.

      Note


      • Perform the test at the normal operating ATF (Automatic Transmission Fluid) temperature 50 to 80°C (122 to 176°F).

      • Do not continuously run this test for longer than 5 seconds.

      • To ensure safety, do this test in a wide, clear level area which provides good traction.

      • The stall test should always be carried out in pairs. One technician should observe the conditions of wheels or wheel stoppers outside the vehicle while the other is doing the test.


      1. Chock the 4 wheels.

      2. Connect an Intelligent Tester to the DLC3.

      3. Fully apply the parking brake.

      4. Using your left foot, keep the brake pedal firmly depressed.

      5. Start the engine.

      6. Shift into the D position. Press all the way down on the accelerator pedal with your right foot.

      7. Quickly read the stall speed at this time.

        Evaluation:
        Problem Possible cause
        (a) Stall engine speed is low in D position

        • Engine power output may be insufficient

        • Stator one-way clutch is not operating properly

        Tech Tips

        If the value is less than the specified value by 600 rpm or more, the torque converter could be faulty.
        (b) Stall engine speed is high in D position

        • Line pressure is too low

        • Forward clutch slipping

        • No.2 one-way clutch not operating properly

        • O/D one-way clutch not operating properly

        • Improper fluid level

  • Measure the time lag.


    1. When the shift lever is shifted while the engine is idling, there will be a certain time lapse or lag before the shock can be felt. This is used for checking the condition of the direct clutch, forward clutch, and 1st and reverse brake.

      Note


      • Perform the test at the normal operating ATF (Automatic Transmission Fluid) temperature: 50 to 80°C (122 to 176°F).

      • Be sure to allow for a 1 minute interval between tests.

      • Perform the test three times, and measure the time lags. Calculate the average value of the three time lags.

    2. Connect an Intelligent Tester to the DLC3.

    3. Fully apply the parking brake.

    4. Start and warm up the engine and check idle speed.

    5. Shift the lever from the N to D position. Using a stop watch, measure the time from when the lever is shifted until the shock is felt.

    6. In the same way, measure the time lag for N → R.

      7. Evaluation (If N → D or N → R time lag is longer than the specified):
      Problem Possible cause
      N → D time lag is longer than specified

      • Line pressure is too low

      • Forward clutch worn

      • O/D one-way clutch not operating properly
      N → R time lag is longer than specified

      • Line pressure is too low

      • Direct clutch worn

      • 1st & reverse brake worn

      • O/D one-way clutch not operating properly