Toyota Sequoia (2005). Manual - part 185

DIDIQ–01

–

DIAGNOSTICS

AUTOMATIC TRANSMISSION

DI–535

729

ROAD TEST

1.

PROBLEM SYMPTOM CONFIRMATION

Based on the result of the customer problem analysis, try to reproduce the symptoms. If the problem is that
the transaxle does not shift up, shift down, or the shift point is too high or too low, conduct the following road
test referring to the automatic shift schedule and simulate the problem symptoms.
2.

ROAD TEST

NOTICE:
Perform the test at the normal operating ATF (Automatic Transmission Fluid) temperature: 50 to 80

°

C

(122 to 176

°

F).

(a)

D position test:
Shift into the D position and fully depress the accelerator pedal and check the following points. Check
up–shift operation.
(1)

Check up–shift operation.
Check that 1 

→

 2, 2 

→

 3, 3 

→

 4 and 4 

→

 5th up–shifts take place, and that the shift points conform

to the automatic shift schedule (See page 

SS–24

).

HINT:
5th Gear Up–shift Prohibition Control

Engine coolant temperature is 55 

°

C (131 

°

F) or less and vehicle speed is at 51 km/h (32 mph) or less.

4th Gear Up–shift Prohibition Control

Engine coolant temperature is 40 

°

C (104 

°

F) or less and vehicle speed is at 45 km/h (28 mph) or less.

5th Gear Lock–up Prohibition Control

Brake pedal is depressed.

Accelerator pedal is released.

Engine coolant temperature is 60 

°

C (140 

°

F) or less.

(2)

Check for shift shock and slip.
Check for shock and slip at the 1 

→

 2, 2 

→

 3, 3 

→

 4 and 4 

→

 5th up–shifts.

(3)

Check for abnormal noise and vibration.
Check for abnormal noise and vibration when up–shifting from 1 

→

 2, 2 

→

 3, 3 

→

 4 and 4 

→

 5

while driving with the shift lever in the D position, and check while driving in the lock–up condition.

HINT:
The check for the cause of abnormal noise and vibration must be done thoroughly as it could also be due
to loss of balance in the differential, torque converter clutch, etc.

(4)

Check kick–down operation.
Check vehicle speeds when the 2nd to 1st, 3rd to 2nd, 4th to 3rd, and 5th to 4th kick–downs take
place while driving with the shift lever in the D position. Confirm that each speed is within the
applicable vehicle speed range indicated in the automatic shift schedule (See page 

SS–24

).

(5)

Check abnormal shock and slip at kick–down.

(6)

Check the lock–up mechanism.

Drive in the D position (5th gear), at a steady speed (lock–up ON).

Lightly depress the accelerator pedal and check that the engine speed does not change
abruptly.

HINT:
If there is a big jump in engine speed, there is no lock–up.

DI–536

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DIAGNOSTICS

AUTOMATIC TRANSMISSION

730

(b)

4 (O/D OFF) position test:
Shift into the 4 (O/D OFF) position and fully depress the accelerator pedal and check the following
points.
(1)

Check up–shift operation.
Check that the 1 

→

 2, 2 

→

 3 and 3 

→

 4 up–shifts take place and that the shift point conforms

to the automatic shift schedule (See page 

SS–24

).

HINT:

There is no 5th up–shift in the 4 position.

4th Gear Lock–up Prohibition Control

Brake pedal is depressed.

Accelerator pedal is released.

Engine coolant temperature is 60 

°

C (140 

°

F) or less.

(2)

Check engine braking.
While driving in the 4 position and 4th gear, release the accelerator pedal and check the engine
braking effect.

(3)

Check for abnormal noises during acceleration and deceleration, and for shock at up–shift and
down–shift.

(4)

Check the lock–up mechanism.

Drive in 4 position 4th gear, at a steady speed (lock–up ON).

Lightly depress the accelerator pedal and check that the engine speed does not change
abruptly.

HINT:
If there is a big jump in engine speed, there is no lock–up.

(c)

3 position test:
Shift into the 3 position and fully depress the accelerator pedal and check the following points.
(1)

Check up–shift operation.
Check that the 1 

→

 2 and 2 

→

 3 up–shifts takes place and that the shift point conforms to the

automatic shift schedule (See page 

SS–24

).

HINT:

There is no 4th up–shift and lock–up in the 3 position.

When the 2nd start switch is ON, there is no 1 

→

2 up–shift and 2 

→

1 down–shift.

(2)

Check engine braking.
While running in the 3 position and 3rd gear, release the accelerator pedal and check the engine
braking effect.

(3)

Check for abnormal noises during acceleration and deceleration, and for shock at up–shift and
down–shift.

(d)

2 position test:
Shift into the 2 position and fully depress the accelerator pedal and check the following points.
(1)

Check up–shift operation.
Check that the 1 

→

 2 up–shift takes place and that the shift point conforms to the automatic shift

schedule (See page 

SS–24

).

HINT:

There is no 3rd up–shift and lock–up in the 2 position.

When the 2nd start switch is ON, there is no 1 

→

2 up–shift and 2 

→

1 down–shift.

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DIAGNOSTICS

AUTOMATIC TRANSMISSION

DI–537

731

(2)

Check engine braking.
While running in the 2 position and 2nd gear, release the accelerator pedal and check the engine
braking effect.

(3)

Check for abnormal noises during acceleration and deceleration, and for shock at up–shift and
down–shift.

(e)

L position test:
Shift into the L position and fully depress the accelerator pedal and check the following points.
(1)

Check no up–shift.
While running in the L position, check that there is no up–shift to 2nd gear.

(2)

Check engine braking.
While running in the L position, release the accelerator pedal and check the engine braking ef-
fect.

(3)

Check for abnormal noises during acceleration and deceleration.

(f)

R position test:
Shift into the R position, lightly depress the accelerator pedal, and check that the vehicle moves back-
ward without any abnormal noise or vibration.

CAUTION:
Before conducting this test, ensure that the test area is free from people and obstruction.

(g)

P position test:
Stop the vehicle on a grade (more than 5

°

) and after shifting into the P position, release the parking

brake. Then, check that the parking lock pawl holds the vehicle in place.

DIDIR–01

DI–538

–

DIAGNOSTICS

AUTOMATIC TRANSMISSION

732

MECHANICAL SYSTEM TESTS

1.

PERFORM MECHANICAL SYSTEM TESTS

(a)

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 positions.

NOTICE:

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 condi-
tions of wheels or wheel stoppers outside the vehicle while the other is doing the test.
(1)

Chock all 4 wheels.

(2)

Connect a hand–held tester to 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.

Stall speed: 2,200 

±

 150 rpm

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

HINT: 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

Clutch No.1 (C

1

) slipping

One–way clutch No.3 (F

3

) is not operating properly

Improper fluid level