Automatic Transaxle System (For Sedan) Mechanical System Tests

Drivetrain. Yaris. Ncp93, 131
U340E Automatic Transmission Transaxle. Yaris. Ncp93, 131

  1. STALL SPEED TEST

  1. SHIFT TIME LAG TEST

Automatic Transaxle System (For Sedan) -- Mechanical System Tests



STALL SPEED TEST
HINT:
This test is to check the overall performance of the engine and transaxle by measuring the stall speeds in the D position.
NOTICE:
  1. Do not perform the stall speed test for longer than 5 seconds.
  2. To ensure safety, perform this test in a wide, clear level area which provides good traction.
  3. The stall speed test must always be carried out by pairs of technicians. One technician must watch the wheels and wheel stoppers from outside the vehicle to make sure they do not slip, while the other performs the test.

  1. Connect the Techstream to the DLC3.

  2. Turn the ignition switch to ON.

  3. Turn the Techstream on.

  4. Enter the following menus: Powertrain / Engine and ECT / Data List / All Data.

  5. Run the vehicle until the ATF (Automatic Transmission Fluid) temperature reaches 50 to 80°C (122 to 176°F).

  6. Allow the engine to idle with the air conditioning OFF.

  7. Chock all 4 wheels.

  8. Set the parking brake and keep the brake pedal firmly depressed with your left foot.

  9. Shift the shift lever to D.

  10. Depress the accelerator pedal all the way down with your right foot.

  11. Read the engine rpm (stall speed) and release the accelerator pedal immediately.

    Standard value:
    2150 +/- 300 rpm

    Evaluation:
    Test Result
    		Possible Cause
    Stall speed is lower than standard value
    1. Stator one-way clutch is not operating properly
    2. Engine power is insufficient
    HINT:
    If the value is less than the specified value by 600 rpm or more, the torque converter could be faulty.
    Stall speed is higher than standard value
    1. Line pressure is too low
    2. Forward clutch (C1) is slipping
    3. No. 2 one-way clutch (F2) is not operating properly

SHIFT TIME LAG TEST
HINT:
This test is to check the conditions of the direct clutch, forward clutch, 1st brake and reverse brake.

  1. Connect the Techstream to the DLC3.

  2. Turn the ignition switch to ON.

  3. Turn the Techstream on.

  4. Enter the following menus: Powertrain / Engine and ECT / Data List / All Data.

  5. Run the vehicle until the ATF (Automatic Transmission Fluid) temperature reaches 50° to 80°C (122° to 176°F).

  6. Allow the engine to idle with the air conditioning OFF.

  7. Set the parking brake and keep the brake pedal firmly depressed with your left foot.

  8. Check the D position time lag.

    1. Shift the shift lever into N and wait for 1 minute. (*1)

    2. Shift the shift lever into D and measure the time until the shock is felt. (*2)

    3. Repeat procedures (*1) and (*2) three times, and calculate the average time of the three tests.

  9. Check the R position time lag.

    1. Shift the shift lever into N and wait for 1 minute. (*3)

    2. Shift the shift lever into R and measure the time until the shock is felt. (*4)

    3. Repeat procedures (*3) and (*4) three times, and calculate the average time of the three tests.

      Standard value:
      D position time lag is less than 1.2 seconds
      R position time lag is less than 1.5 seconds

      Evaluation :
      Test Result
      		Possible Cause
      D position time lag exceeds standard value
      1. Line pressure is too low
      2. Forward clutch (C1) is worn
      3. No. 2 one-way clutch (F2) is not operating properly
      R position time lag exceeds standard value
      1. Line pressure is too low
      2. Reverse clutch (C3) is worn
      3. 1st and reverse brake (B3) is worn