2001 TOYOTA SEQUOIA automatic transmission

IN01T±18
± INTRODUCTIONHOW TO TROUBLESHOOT ECU CONTROLLED
SYSTEMSIN±23
23 Author: Date:
HOW TO TROUBLESHOOT ECU CONTROLLED SYSTEMS
GENERAL INFORMATION
A large number of ECU controlled systems are used in the SEQUOIA. In general, the ECU controlled system
is considered to be a very intricate system requiring a high level of technical knowledge and expert skill to
troubleshoot. However, the fact is that if you proceed to inspect the circuits one by one, troubleshooting of
these systems is not complex. If you have adequate understanding of the system and a basic knowledge
of electricity, accurate diagnosis and necessary repair can be performed to locate and fix the problem. This
manual is designed through emphasis of the above standpoint to help service technicians perform accurate
and effective troubleshooting, and is compiled for the following major ECU controlled systems:
The troubleshooting procedure and how to make use of it are described on the following pages.
SystemPage
1. EngineDI±1
2. Automatic TransmissionDI±515
3. Air Suspension Control SystemDI±695
4. Tire Pressure Warning SystemDI±796
5. ABS with EBD & BA & TRAC & VSC SystemDI±891
6. Can Communication SystemDI±1060
7. Supplemental Restraint SystemDI±1118
8. Power Seat Control System w/ Driving Position MemoryDI±1501
9. Cruise Control SystemDI±1536
10.Engine Immobilizer SystemDI±1570
11. Combination Meter SystemDI±1601
12.Sliding Roof SystemDI±1661
13.Body Control SystemDI±1678
14.Driver Door Control SystemDI±1778
15.Passenger Door Control SystemDI±1814
16.Back Door Control SystemDI±1850
17.Multiplex Communication SystemDI±1887
18.Audio SystemDI±1955
19.Rear Seat Audio SystemDI±2044
20.Rear Seat Entertainment SystemDI±2078
21.Navigation SystemDI±2159
22.Air Conditioning SystemDI±2297
FOR USING OBD II SCAN TOOL OR TOYOTA HAND±HELD TESTER

Before using the scan tool or tester, the scan tool's instruction book or tester's operator manual should
be read thoroughly.

If the scan tool or tester cannot communicate with ECU controlled systems when you have connected
the cable of the scan tool or tester to DLC3, turned the ignition switch ON and operated the scan tool,
there is a problem on the vehicle side or tool side.
(1) If communication is normal when the tool is connected to another vehicle, inspect the diagnosis
data link line (Bus
line) or ECU power circuit of the vehicle.
(2) If communication is still not possible when the tool is connected to another vehicle, the problem
is probably in the tool itself, so perform the Self Test procedures outline in the Tester Operator's
Manual.

IN±26± INTRODUCTIONHOW TO TROUBLESHOOT ECU CONTROLLED
SYSTEMS
26 Author: Date:
2005 SEQUOIA (RM1146U)
2. SYMPTOM CONFIRMATION AND DIAGNOSTIC TROUBLE CODE CHECK
The diagnostic system in the SEQUOIA fulfills various functions. The first function is the Diagnostic Trouble
Code Check in which a malfunction in the signal circuits to the ECU is stored in code in the ECU memory
at the time of occurrence, to be output by the technician during troubleshooting. Another function is the Input
Signal Check which checks if the signals from various switches are sent to the ECU correctly.
By using these check functions, the problem areas can be narrowed down quickly and troubleshooting can
be performed effectively. Diagnostic functions are incorporated in the following systems in the SEQUOIA.
SystemDiagnostic Trouble
Code CheckInput Signal Check
(Sensor Check)Diagnostic Test
Mode (Active Test)
1. Engine(with Check
Mode)
2. Automatic Transmission(with Check
Mode)
3. Air Suspension Control System(with Check
Mode)
4. Tire Pressure Warning System
5. ABS with EBD & BA & TRAC & VSC System
6. Can Communication System
7. Supplemental Restraint System(with Check
Mode)
8. Power Seat Control System w/ Driving Position Memory
9. Cruise Control System
10.Engine Immobilizer System
11. Combination Meter System
12.Sliding Roof System
13.Body Control System
14.Driver Door Control System
15.Passenger Door Control System
16.Back Door Control System
17.Multiplex Communication System
18.Audio System
19.Rear Seat Audio System
20.Rear Seat Entertainment System
21.Air Conditioning System
In diagnostic trouble code check, it is very important to determine whether the problem indicated by the diag-
nostic trouble code is still occurring or occurred in the past but returned to normal at present. In addition,
it must be checked in the problem symptom check whether the malfunction indicated by the diagnostic
trouble code is directly related to the problem symptom or not. For this reason, the diagnostic trouble codes
should be checked before and after the symptom confirmation to determine the current conditions, as shown
in the table on the next page. If this is not done, it may, depending on the case, result in unnecessary trouble-
shooting for normally operating systems, thus making it more difficult to locate the problem, or in repairs not
pertinent to the problem. Therefore, always follow the procedure in correct order and perform the diagnostic
trouble code check.

IN04Q±33
IN±40
± INTRODUCTIONTERMS
40 Author: Date:
2005 SEQUOIA (RM1146U)
TERMS
ABBREVIATIONS USED IN THIS MANUAL
AbbreviationsMeaning
ABSAnti±Lock Brake System
A/CAir Conditioner
ACAlternating Current
ACCAccessory
ACISAcoustic Control Induction System
ACMActive Control Engine Mount
ACSDAutomatic Cold Start Device
A.D.D.Automatic Disconnecting Differential
A/FAir±Fuel Ratio
AHCActive Height Control Suspension
ALRAutomatic Locking Retractor
ALTAlternator
AMPAmplifier
ANTAntenna
APPROX.Approximately
ASSYAssembly
A/T, ATMAutomatic Transmission (Transaxle)
AT FAutomatic Transmission Fluid
AUTOAutomatic
AUXAuxiliary
AV GAverage
AV SAdaptive Variable Suspension
B+Battery Voltage
BABrake Assist
BACSBoost Altitude Compensation System
BATBattery
BDCBottom Dead Center
B/LBi±Level
B/SBore±Stroke Ratio
BTDCBefore Top Dead Center
BVSVBimetallic Vacuum Switching Valve
CBCircuit Breaker
CCoCatalytic Converter For Oxidation
CCVCanister Closed Valve
CDCompact Disc
CFCornering Force
CGCenter Of Gravity
CHChannel
CKDComplete Knock Down
COMB.Combination
CPECoupe
CPSCombustion Pressure Sensor
CPUCentral Processing Unit
CRSChild Restraint System
CTRCenter
C/VCheck Valve
CVControl Valve
CWCurb Weight

± MAINTENANCEINSIDE VEHICLE
MA±3
50 Author: Date:
2005 SEQUOIA (RM1146U)
13. ACCELERATOR PEDAL
Check the pedal for smooth operation and uneven pedal effort or catching.
14. BRAKE PEDAL
(See page BR±6)
(a) Check the pedal for smooth operation.
(b) Check that the pedal has the proper reserve distance and free play.
(c) Check the brake booster function.
15. BRAKES
At a safe place, check that the brakes do not pull to one side when applied.
16. PARKING BRAKE
(See page BR±9)
(a) Check that the lever has the proper travel.
(b) On a safe incline, check that the vehicle is held securely with only the parking brake applied.
17. AUTOMATIC TRANSMISSION ºPARKº MECHANISM
On a safe incline, check that the vehicle is held securely with the selector lever in ºPº position and all brakes
released.

MA003±50
MA±4
± MAINTENANCEUNDER HOOD
51 Author: Date:
2005 SEQUOIA (RM1146U)
UNDER HOOD
GENERAL MAINTENANCE
1. GENERAL NOTES

Maintenance items may vary from country to country. Check the owner's manual supplement in which
the maintenance schedule is shown.

Every service item in the periodic maintenance schedule must be performed.

Periodic maintenance service must be performed according to whichever interval in the periodic main-
tenance schedule occurs first, the odometer reading (miles) or the time interval (months).

Maintenance service after the last period should be performed at the same interval as before unless
otherwise noted.

Failure to do even one item can cause the engine to run poorly and increase exhaust emissions.
2. WINDSHIELD WASHER FLUID
Check that there is sufficient fluid in the tank.
3. ENGINE COOLANT LEVEL
Check that the coolant level is between the FULL and LOW lines on the see±through reservoir.
4. RADIATOR AND HOSES
(a) Check that the front of the radiator is clean and not blocked with leaves, dirt or bugs.
(2UZ±FE engine: See page CO±14)
(b) Check the hoses for cracks, kinks, rot or loose connections.
5. BATTERY ELECTROLYTE LEVEL
Check that the electrolyte level of all battery cells is between the upper and lower level lines on the case.
6. BRAKE AND CLUTCH FLUID LEVELS
Check that the brake and clutch fluid levels are near the upper level line on the see±through reservoirs.
7. ENGINE DRIVE BELTS
Check all drive belts for fraying, cracks, wear or oiliness.
8. ENGINE OIL LEVEL
Check the level on the dipstick with the engine turned off.
9. POWER STEERING FLUID LEVEL
(a) Check the level on the dipstick.
(b) The level should be in the HOT or COLD range depending on the fluid temperature.
10. AUTOMATIC TRANSMISSION FLUID LEVEL
(a) Park the vehicle on a level surface.
(b) With the engine idling and the parking brake applied, shift the selector into all positions from the P to
L, and then shift into the P position.
(c) Pull out the dipstick and wipe off the fluid with a clean rag. Re±insert the dipstick and check that the
fluid level is in the HOT range.
(d) Do this check with the fluid at normal driving temperature (70 ± 80°C, 158 ± 176°F).
HINT:
Wait until the engine cools down (approx. 30 min.) before checking the fluid level after extended driving at
high speeds, in hot weather, in heavy traffic or pulling a trailer.
11. EXHAUST SYSTEM
(a) Visually inspect for cracks, holes or loose supports.
(b) If any change in the sound of the exhaust or smell of the exhaust fumes is noticed, find the cause and
correct.

B07270
MA04O±03
B07272
Drive Shaft Boots
B07271
Dust Cover
Z04824
A/T
OK if coolOK if hot
Add if coolAdd if hot
± MAINTENANCECHASSIS
MA±7
54 Author: Date:
2005 SEQUOIA (RM1146U)
CHASSIS
INSPECTION
1. INSPECT STEERING LINKAGE
(a) Check the steering wheel free play (See page SR±9).
(b) Check the steering linkage for looseness or damage.
Check that:

Tie rod ends do not have excessive play.

Dust seals are not damaged.

Boot clamps are not loose.
2. INSPECT SRS AIRBAG (See page RS±3)
3. INSPECT STEERING GEAR HOUSING OIL
Check the steering gear housing for oil leaks.
If leakage is found, check the cause and repair.
4. 4WD:
INSPECT DRIVE SHAFT BOOTS
Inspect the drive shaft boots for clamp looseness, grease leak-
age or damage.
5. INSPECT BALL JOINTS AND DUST COVERS
(a) Inspect the ball joints for excessive looseness.
(b) Inspect the dust cover for damage.
6. 2WD:
CHECK OIL LEVEL IN AUTOMATIC TRANSMISSION
AND DIFFERENTIAL
(a) Automatic transmission:
Check that the fluid level is in the ºHOTº range at the nor-
mal operating temperature (70 ± 80°C or 158 ± 176°F)
and add as necessary.
NOTICE:
Do not overfill.
Transmission fluid (A/T): See page
DI±524

B07273
Filler Plug
Differential
Z04824
A/T
OK if coolOK if hot
Add if coolAdd if hot
P23117
Filler Plug
Transfer
B07968
Differential
Front
RearFiller Plug
Filler Plug MA±8
± MAINTENANCECHASSIS
55 Author: Date:
2005 SEQUOIA (RM1146U)
(b) Differential:
Remove the filler plug and feel inside the hole with your
finger. Check that the oil comes to within 5 mm (0.20 in.)
of the bottom edge of the hole. If the level is low, add oil
until it reaches the bottom of the filler hole.
Differential oil: See page SA±129
7. 4WD:
CHECK OIL LEVEL IN AUTOMATIC TRANSMISSION,
TRANSFER AND DIFFERENTIAL
(a) Automatic transmission:
Check that the fluid level is in the ºHOTº range at the nor-
mal operating temperature (70 ± 80°C or 158 ± 176°F)
and add as necessary.
NOTICE:
Do not overfill.
Transmission fluid (A/T): See page DI±524
(b) Transfer:
Remove the filler plug and feel inside the hole with your
finger. Check that the oil comes to within 5 mm (0.20 in.)
of the bottom edge of the hole. If the level is low, add oil
until it reaches the bottom of the filler hole.
Transfer oil: See page TR±4
(c) Differential:
Remove the filler plug and feel inside the hole with your
finger. Check that the oil comes to within 5 mm (0.20 in.)
of the bottom edge of the hole. If the level is low, add oil
until it reaches the bottom of the filler hole.
Front differential oil: See page SA±38
Rear differential oil: See page SA±129

P23118Drain Plug Transfer
B07969
Differential
Front
RearDrain plug
Drain plug
B07952Drain Plug
MA0099
OK if coolOK if hot
Add if coolAdd if hot
± MAINTENANCECHASSIS
MA±9
56 Author: Date:
2005 SEQUOIA (RM1146U)
8. REPLACE TRANSFER AND DIFFERENTIAL OIL
(a) Transfer:
Remove the transfer cover.
(b) Remove the drain plug and drain the oil.
(c) Reinstall the drain plug securely.
(d) Add new oil until it reaches the bottom of the filler hole.
Transfer oil: See page TR±4
Front differential oil: See page SA-38
Rear differential oil: See page SA±129
9. REPLACE AUTOMATIC TRANSMISSION FLUID
(a) Remove the drain plug and drain the fluid.
(b) Reinstall the drain plug securely.
(c) With the engine OFF, add new fluid through the dipstick
tube.
Transmission fluid (A/T): See page DI±524
(d) Start the engine and shift the selector into all positions
from ºPº through ºLº and then shift into ºPº.
(e) With the engine idling, check the fluid level.
Add fluid up to the ºCOOLº level on the dipstick.
(f) Check that the fluid level is in the ºHOTº range at the nor-
mal operating temperature (70 ± 80°C or 158 ± 176°F)
and add as necessary.
NOTICE:
Do not overfill.
10. RECOAT FRONT WHEEL BEARINGS AND THRUST
BUSH
(a) Recoat the front wheel bearing with grease (See page
SA±28).