Last Modified: 04-05-2023 6.11:8.1.0 Doc ID: RM10000000101L5
Model Year Start: 2017 Model: Sienna Prod Date Range: [08/2016 -           ]
Title: UA80F (AUTOMATIC TRANSMISSION / TRANSAXLE): AUTOMATIC TRANSAXLE SYSTEM: MECHANICAL SYSTEM TESTS; 2017 - 2020 MY Sienna [08/2016 -        ]

MECHANICAL SYSTEM TESTS

STALL SPEED TEST

HINT:

This test is to check the overall performance of the engine and transaxle.

CAUTION:

  • This test should be done on a paved surface (a surface that is not slippery).
  • To ensure safety, perform this test in an open and level area that provides good traction.
  • A stall speed test should always be performed with at least 2 people. One person should observe the condition of the wheels and wheel chocks while the other is performing the test.

NOTICE:

  • Do not perform the stall speed test for longer than 5 seconds.
  • When performing the stall speed test repeatedly, wait for 15 seconds or more between tests.
  • Perform this test with the ATF (Automatic Transaxle Fluid) at the normal operating temperature: 50 to 80°C (122 to 176°F)
  • Check that there is no obstruction within 5 m (16.4 ft.) of the driving direction.

    When torque is restricted by a safety function of the intelligent clearance sonar system, etc., the stall characteristics may not be normal.

(a) Connect the Techstream to the DLC3.

(b) Drive the vehicle until the transaxle fluid temperature has reached 50 to 80°C (122 to 176°F).

(c) Allow the engine to idle with the air conditioning and headlights off.

(d) Chock all 4 wheels.

(e) Set the parking brake and keep the brake pedal depressed firmly with your left foot.

(f) Move the shift lever to D.

(g) Depress the accelerator pedal as much as possible with your right foot.

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

Standard Value:

Stall Speed

2370 rpm

+ 200 rpm

- 300 rpm

Evaluation

Test Result

Possible Cause

Stall speed is lower than standard value
  • Engine power output may be insufficient
  • Stator one-way clutch not operating properly

HINT:

If the value is less than the specified value by 600 rpm or more, the torque converter assembly may be malfunctioning.

Stall speed is higher than standard value
  • Line pressure is too low
  • No. 1 clutch (C1) slipping
  • No. 2 brake (B2) slipping
  • Improper fluid level

SHIFT TIME LAG TEST

HINT:

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

(a) Connect the Techstream to the DLC3.

(b) Drive the vehicle until the transaxle fluid temperature has reached 50 to 80°C (122 to 176°F).

(c) Allow the engine to idle with the air conditioning off.

(d) Set the parking brake and keep the brake pedal depressed firmly.

(e) Check the D position time lag.

(1) Move the shift lever to N and wait for 1 minute.

(2) Move the shift lever to D and measure the time until shock is felt.

(3) Repeat the 2 steps above 3 times, and calculate the average time of the 3 tests.

Standard Value:

D position time lag is less than 1.5 seconds

(f) Check the R position time lag.

(1) Move the shift lever to N and wait for 1 minute.

(2) Move the shift lever to R and measure the time until shock is felt.

(3) Repeat the 2 steps above 3 times, and calculate the average time of the 3 tests.

Standard Value:

R position time lag is less than 1.5 seconds

Evaluation

Test Result

Possible Cause

D position time lag exceeds standard value
  • Line pressure is low
  • No. 1 clutch (C1) is worn
  • No. 2 brake (B2) is worn

R position time lag exceeds standard value
  • Line pressure is low
  • No. 3 clutch (C3) is worn
  • No. 2 brake (B2) is worn