TOYOTA SIENNA 2007 Service Repair Manual

AX–8U151F AUTOMATIC TRANSAXLE – AUTOMATIC TRANSAXLE SYSTEM
AX
HINT:
(See page IN-35).
NEXT
HINT:
(See page AX-27).
HINT:
(See page AX-127, AX-123 and AX-148).
NG
OK
HINT:
(See page AX-12).
NG
OK
HINT:
(See page AX-14).
NG
OK
HINT:
(See page AX-15).
NGSymptom occurs: Go to step 9
8Symptom Simulation
9DTC Check
DTC is not output: Go to step 10
DTC is output: Go to step 17
10Basic Inspection
Go to step 19
11Mechanical System Test
Go to step 16
12Hydraulic Test
Go to step 16
13Manual Shifting Test
Go to step 15

U151F AUTOMATIC TRANSAXLE – AUTOMATIC TRANSAXLE SYSTEMAX–9
AX
OK
HINT:
(See page AX-19).
NG
OK
HINT:
(See page AX-19).
NEXT
HINT:
(See page AX-35).
NEXT
NEXT
NEXT
NEXT
14Problem Symptoms Table Chapter 1
Go to step 18
15Problem Symptoms Table Chapter 2
16Part Inspection
Go to step 19
17DTC Chart
18Circuit Inspection
19Repair or Replace
20Confirmation Test
End

AX–10U151F AUTOMATIC TRANSAXLE – AUTOMATIC TRANSAXLE SYSTEM
AX
ROAD TEST
1. PROBLEM SYMPTOM CONFIRMATION
(a) 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 ATF temperature 50 to 80
C
(122 to 176
F) in the normal operation.
(a) D position test:
Shift into the D position and fully depress the
accelerator pedal and check the following points.
(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-31).
HINT:
5th Gear Up-shift Prohibition Control
• Engine coolant temperature is 55
C (131F)
or less and vehicle speed is at 80 km/h (176
mph) or less.
• ATF temperature is -2
C (28F) or less.
4th Gear Up-shift Prohibition Control
• Coolant temperature is 47
C (117F) or less
and vehicle speed is at 55 km/h (34 mph) or
less.
5th and 4th Gear Lock-up Prohibition Control
• Brake pedal is depressed.
• Accelerator pedal is released.
• Coolant temperature is 60
C (140F) 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.
Drive in the D position lock-up or 5th gear, and
check for abnormal noises and vibration.
HINT:
The check for the cause of abnormal noise and
vibration must be done very thoroughly as it
could also be due to loss of balance in the
differential, torque converter clutch, etc.
(4) Check kick-down operation.
Check that the possible kick-down vehicle speed
limits for 2nd to 1st, 3rd to 2nd, 4th to 3rd, 5th to
4th kick-downs conform to those indicated on
the automatic shift schedule while driving
through all gears with the shift lever in the D
position (See page SS-31).
(5) Check abnormal shock and slip at kick-down.

U151F AUTOMATIC TRANSAXLE – AUTOMATIC TRANSAXLE SYSTEMAX–11
AX
(6) Check the lock-up mechanism.
• Drive in 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:
• There is no lock-up in the 1st and 2nd gear.
• 4th lock-up operates while uphill-downhill
control is active in D position.
• 3rd lock-up operates while uphill-downhill
control is active in D position.
• ATF temperature is 120
C (248F) or more.
• If there is a big jump in engine speed, there is
no lock-up.
(b) 4 (O/D OFF) position test:
Shift into the 4 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-shift
take place and that the shift point conforms to
the automatic shift schedule (See page SS-31).
HINT:
There is no 5th up-shift in the 4 position.
(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 noise during acceleration
and deceleration, and for shock at up-shift and
down-shift.
(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-shift take
place and that the shift point conforms to the
automatic shift schedule (See page SS-31).
HINT:
There is no 4th up-shift and lock-up in the 3
position.
(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 noise during acceleration
and deceleration, and for shock at up-shift and
down-shift.

AX–12U151F AUTOMATIC TRANSAXLE – AUTOMATIC TRANSAXLE SYSTEM
AX
(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-31).
HINT:
There is no 3rd up-shift and lock-up in the 2
position.
(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 noise 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.
HINT:
There is no lock-up in the L position.
(2) Check engine braking.
While running in the L position, release the
accelerator pedal and check the engine braking
effect.
(3) Check for abnormal noise during acceleration
and deceleration.
(f) R position test:
Shift into the R position and fully depress the
accelerator pedal and check for slipping.
CAUTION:
Before conducting this test ensure that the test
area is free from people and obstruction.
(g) P position test:
Stop the vehicle on the 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.
(h) Uphill/downhill control function test:
(1) Check that the gear does not up-shift to the 4th
or 5th gear while the vehicle is driving uphill.
(2) Check that the gear automatically down-shifts
from 5th to 4th or from the 4th to 3rd gear when
brake is applied while the vehicle is driving
downhill.

U151F AUTOMATIC TRANSAXLE – AUTOMATIC TRANSAXLE SYSTEMAX–13
AX
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 transaxle and engine by
measuring the stall speeds in the D position.
NOTICE:
• Driving test should be done on a paved road
(a nonskid road).
• Perform the test at the normal operating ATF
(Automatic Transmission Fluid) temperature
50 to 80
C (122 to 176F).
• Do not continuously run this test for longer
than 10 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 the intelligent tester together with the
CAN VIM (controller area network vehicle
interface module) to the DLC3.
(3) Fully apply the parking brake.
(4) Keep your left foot pressed firmly on the brake
pedal.
(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:
2,600 +- 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 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
• Forward clutch slipping
• U/D (Underdrive) brake slipping
• U/D (Underdrive) one-way clutch is not operating properly
• No.1 one-way clutch not operating properly
• Improper fluid level

AX–14U151F AUTOMATIC TRANSAXLE – AUTOMATIC TRANSAXLE SYSTEM
AX
(b) 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 clutch and brake.
NOTICE:
• Perform the test at the normal operating
ATF (Automatic Transmission Fluid)
temperature: 50 to 80
C (122 to 176F).
• Be sure to allow 1 minute interval between
tests.
• Perform the test three times, and measure
the time lags. Calculate the average value
of the three time lags.
• When conducting stall test, do not
continue more than 10 seconds.
(2) Connect the intelligent tester together with the
CAN VIM (controller area network vehicle
interface module) to the DLC3.
(3) Fully apply the parking brake.
(4) Start and warm up the engine and check idle
speed.
Idle speed:
approx. 700 rpm (In N position and A/C
OFF)
(5) Shift the lever from N to D position. Using a stop
watch, measure the time from when the lever is
shifted until the shock is felt.
Time lag:
N
D less than 1.2 seconds
(6) In the same way, measure the time lag for N

R.
Time lag:
N
R less than 1.5 seconds
Evaluation (If N
D or N R time lag is longer than the specified):
Problem Possible cause
N
D time lag is longer• Line pressure is too low
• Forward clutch worn
• No.1 one-way clutch is not operating properly
• U/D (Underdrive) one-way clutch is not operating
• U/D (Underdrive) brake worn
N
R time lag is longer• Line pressure is too low
• Reverse clutch worn
• 1st and reverse brake worn
• U/D (Underdrive) brake worn

U151F AUTOMATIC TRANSAXLE – AUTOMATIC TRANSAXLE SYSTEMAX–15
AX
HYDRAULIC TEST
1. PERFORM HYDRAULIC TEST
(a) Measure the line pressure.
NOTICE:
• Perform the test at the normal operating ATF
(Automatic Transmission Fluid) temperature:
50 to 80
C (122 to 176F).
• The line pressure 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 performing the test.
• 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.
• When conducting stall test, do not continue
more than 10 seconds.
(1) Warm up the ATF (Automatic Transmission
Fluid).
(2) Lift the vehicle up.
(3) Remove the engine under cover.
(4) Connect the intelligent tester together with the
CAN VIM (controller area network vehicle
interface module) to the DLC3.
(5) Remove the test plug A on the transaxle case
front left side and install the SST.
SST 09992-00095 (09992-00231, 09992-
00271)
NOTICE:
There is a difference in installation point
between D position and R position.
(6) Start the engine.
(7) Using intelligent tester, shift to D position and
hold 3rd gear by active test, and measure the
line pressure in idling.
Specified line pressure:
(8) Turn the ignition switch off.
C160153E01
Condition
D position kPa (kgf / cm2, psi)
Idling372 to 412 kPa
(3.8 to 4.2 kgf/cm
2, 54 to 60 psi)

AX–16U151F AUTOMATIC TRANSAXLE – AUTOMATIC TRANSAXLE SYSTEM
AX
(9) Disconnect the connector of the transmission
wire.
HINT:
Disconnect the connector only when performing
the D position stall test.
(10)Start the engine.
(11)Firmly depress the brake pedal, shift to the D
position, depress the accelerator pedal all the
way down and check the line pressure while the
stall test is performed.
Specified line pressure:
(12)Turn the ignition switch off.
(13)Remove the SST, install the test plug A.
(14)Remove the test plug B, install the SST and
start engine.
SST 09992-00095 (09992-00231, 09992-
00271)
(15)Connect the transmission wire connector,
depress the brake pedal firmly, shift to the R
position and check that the line pressure while
the engine is idling and during the stall test.
Specified line pressure:
(16)Remove the SST, install the test plug B.
(17)Clear the DTC.
Evaluation:
C160154E01
Condition
D position kPa (kgf / cm2, psi)
Stall test931 to 1,031 kPa
(9.5 to 10.5 kgf/cm
2, 135 to 150 psi)
Condition
R position kPa (kgf / cm
2, psi)
Idling672 to 742 kPa
(6.9 to 7.6 kgf/cm
2, 97 to 108 psi)
Stall test1,768 to 1,968 kPa
(18.0 to 20.1 kgf/cm
2, 256 to 285 psi)
Problem Possible cause
Measured values are higher than specified in all positions• Shift solenoid valve SLT defective
• Regulator valve defective
Measured values are lower than specified in all positions• Shift solenoid valve SLT defective
• Regulator valve defective
• Oil pump defective
• U/D (Underdrive) direct clutch defective
Pressure is low in the D position only• D position circuit fluid leak
• Forward clutch defective
Pressure is low in the R position only• R position circuit fluid leak
• Reverse clutch defective
• 1st and reverse brake defective

U151F AUTOMATIC TRANSAXLE – AUTOMATIC TRANSAXLE SYSTEMAX–17
AX
MANUAL SHIFTING TEST
1. PERFORM MANUAL SHIFTING TEST
HINT:
• With this test, it can be determined whether the
trouble occurs in the electrical circuit or is a
mechanical problem in the transaxle.
• If any abnormalities are found in the following test, the
problem is in the transaxle itself.
(a) Disconnect the connector of the transmission wire.
(b) Drive with the transmission wire disconnected.
Shifting the shift lever in the order of L, 2, 3, 4 and D
position to check whether the shifting condition
changes the table below.
HINT:
When driving with the transmission wire
disconnected, the shift lever position is in L or 2, the
gear position is held in 3rd and the shift lever
position is in 3, 4 or D, the gear position is held in
4th. However, when the shift position is in R or P, the
operation is same as usual.
(c) Connect the connector of the transmission wire.
(d) Clear the DTC (See page AX-27).
C160154E01
Shift Position Shifting Condition
L
2 No Shift (Not Change)
2
3 Down Shift Up Shift
3
4 D No Shift (Not Change)