2001 TOYOTA SEQUOIA ECU

FI1066
IN0D9±03
Z11554
Seal Lock Adhesive IN±4
± INTRODUCTIONREPAIR INSTRUCTIONS
4 Author: Date:
2005 SEQUOIA (RM1146U)
REPAIR INSTRUCTIONS
GENERAL INFORMATION
BASIC REPAIR HINT
(a) Prevent damage and maintain vehicle cleanliness by pro-
tective covering on the fender, seat and floor.
(b) During disassembly, keep parts in the appropriate order
to facilitate reassembly.
(c) Installation and removal of battery terminal:
(1) Before performing electrical work, disconnect the
negative (±) terminal cable from the battery.
(2) If it is necessary to disconnect the battery for in-
spection or repair, first disconnect the negative (±)
terminal cable.
(3) When disconnecting the terminal cable, to prevent
damage to battery terminal, loosen the cable nut
and raise the cable straight up without twisting or
prying it.
(4) Clean the battery terminals and cable ends with a
clean shop rag. Do not scrape them with a file or oth-
er abrasive objects.
(5) Install the cable ends to the battery terminals after
loosening the nut and tighten the nut. Do not use a
hammer to tap the cable ends onto the terminals.
(6) Be sure the cover for the positive (+) terminal is
properly in place.
(d) Check hose and wiring connectors to make sure that they
are connected securely and correctly.
(e) Non±reusable parts
(1) Always replace cotter pins, gaskets, O±rings, oil
seals, etc. with new ones.
(2) Non±reusable parts are indicated in the component
illustrations by the ºº symbol.
(f) Precoated parts
Precoated parts are bolts, nuts, etc. that are coated with
a seal lock adhesive at the factory.
(1) If a precoated part is retightened, loosened or
caused to move in any way, it must be recoated with
the specified adhesive.
(2) When reusing precoated parts, clean off the old
adhesive and dry with compressed air. Then apply
the specified seal lock adhesive to the bolt, nut or
threads.

IN0253
WRONG CORRECT
IN0252
WRONG CORRECT IN±6
± INTRODUCTIONREPAIR INSTRUCTIONS
6 Author: Date:
2005 SEQUOIA (RM1146U)
(k) Care must be taken when jacking up and supporting the
vehicle. Be sure to lift and support the vehicle at the prop-
er locations (See page IN±8).
Cancel the parking brake on the level place and
shift the transmission in N position.
When jacking up the front wheels of the vehicle, first
place stoppers behind the rear wheels.
When jacking up the rear wheels of the vehicle, first
place stoppers before the front wheels.
When either the front or rear wheels only should be
jacked up, set rigid racks and place stoppers in front
and behind of the other wheels on the ground.
After the vehicle is jacked up, be sure to support it
on rigid racks. It is extremely dangerous to do any
work on a vehicle raised on a jack, even for a job that
can be finished quickly.
(l) Observe the following precautions to avoid damage to the
following parts:
(1) Do not open the cover or case of the ECU unless
absolutely necessary. (If the IC terminals are
touched, the IC may be destroyed by static electric-
ity.)
(2) To disconnect vacuum hoses, pull off the end, not
the middle of the hose.
(3) To pull apart electrical connectors, pull on the con-
nector itself, not the wires.
(4) Be careful not to drop electrical components, such
as sensors or relays. If they are dropped on a hard
floor, they should be replaced and not reused.
(5) When steam cleaning an engine, protect the elec-
tronic components, air filter and emission±related
components from water.
(6) Never use an impact wrench to remove or install
temperature switches or temperature sensors.

B04770
IN±18
± INTRODUCTIONFOR ALL OF VEHICLES
18 Author: Date:
2005 SEQUOIA (RM1146U)
(4) Check that the VSC TRAC warning light blinks.
(5) After the measurement, remove the SST and re-
start the engine. At this time, make sure that the
VSC TRAC warning light is off.
(b) Notice in VSC operation.
(1) Removal and reinstallation of VSC±related compo-
nents may cause misadjustment of them. Do not re-
move or reinstall them unless necessary.
(2) When conducting VSC±related operations, do not
fail to make sure that the preparation and the finish-
ing of the operation are all performed in accordance
with the direction in this text.
3. FOR VEHICLES EQUIPPED WITH A CATALYTIC CONVERTER
CAUTION:
If a large amount of unburned gasoline flows into the converter, it may overheat and create a fire haz-
ard. To prevent this, observe the following precautions and explain them to your customer.
(a) Use only unleaded gasoline.
(b) Avoid prolonged idling.
Avoid running the engine at idle speed for more than 20 minutes.
(c) Avoid spark jump test.
(1) Perform spark jump test only when absolutely necessary. Perform this test as rapidly as possible.
(2) While testing, never race the engine.
(d) Avoid prolonged engine compression measurement.
Engine compression tests must be done as rapidly as possible.
(e) Do not run engine when fuel tank is nearly empty.
This may cause the engine to misfire and create an extra load on the converter.
(f) Avoid coasting with ignition turned off.
(g) Do not dispose of used catalyst along with parts contaminated with gasoline or oil.
4. IF VEHICLE IS EQUIPPED WITH MOBILE COMMUNICATION SYSTEM
For vehicles with mobile communication systems such as two±way radios and cellular telephones, observe
the following precautions.
(1) Install the antenna as far as possible away from the ECU and sensors of the vehicle's electronic
system.
(2) Install the antenna feeder at least 20 cm (7.87 in.) away from the ECU and sensors of the ve-
hicle's electronic systems. For details about ECU and sensor locations, refer to the section on
the applicable component.
(3) Do not wind the antenna feeder together with the other wiring as much as possible, also avoid
running the antenna feeder parallel with other wire harness.
(4) Check that the antenna and feeder are correctly adjusted.
(5) Do not install powerful mobile communication system.

± INTRODUCTIONFOR ALL OF VEHICLES
IN±19
19 Author: Date:
2005 SEQUOIA (RM1146U)
5. FOR USING OBD II SCAN TOOL OR TOYOTA HAND±HELD TESTER
CAUTION:
Observe the following for safety reasons:

Before using the OBD II scan tool or TOYOTA hand±held tester, the OBD II scan tool's instruc-
tion book or TOYOTA hand±held tester's operator manual should be read thoroughly.

Be sure to route all cables securely when driving with the OBD II scan tool or TOYOTA hand±
held tester connected to the vehicle. (i.e. Keep cables away from feet, pedals, steering wheel
and shift lever.)

Two persons are required when test driving with the OBD II scan tool or TOYOTA hand±held
tester, one person to drive the vehicle and one person to operate the OBD II scan tool or TOYO-
TA hand±held tester.

IN0KK±01
IN±20
± INTRODUCTIONFOR ALL OF VEHICLES
20 Author: Date:
2005 SEQUOIA (RM1146U)
INITIALIZATION
NOTICE:
When disconnecting the battery terminal, initialize the following systems after the terminal is recon-
nected.
System NameSee Step No.
Back Door Power Window Control SystemStep 1
INITIALIZE BACK DOOR POWER WINDOW CONTROL SYSTEM
NOTICE:
Resetting the power window regulator motor (initializing the pulse sensor) is necessary if: 1) the bat-
tery terminal cable is disconnected; 2) the back door ECU, wire harness, power window regulator
switch, power window regulator assembly and power window regulator motor are replaced or re-
moved/installed; or 3) the P/W fuse is replaced or removed. If resetting is not performed, the master
switch assembly will not be able to operate the AUTO operation function, jam protection function and
remote operation function.
(a) Turn the ignition switch ON.
(b) Open the power window halfway by pressing the power window switch.
(c) Fully pull up on the switch until the power window is fully closed and continue to hold the switch for
at least 1 second.
(d) Check that the AUTO UP/DOWN function operates normally.
If the AUTO UP/DOWN function operates normally, reset operations are complete. If abnormal, follow the
steps (e) to (g) below.
(e) Disconnect the negative battery terminal cable for 10 seconds.
(f) Connect the battery terminal cable.
(g) Perform the steps (a) to (d) again.

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.

IN01U±14
Vehicle Brought to Workshop
Customer Problem
Analysis
Symptom Confirmation
and Diagnostic Trouble
Code Check
Symptom Simulation
Diagnostic Trouble
Code Chart
Problem Symptoms Table
Circuit Inspection or Parts
Inspection
Repair
Confirmation Test
End 1
2
43
5
6
7
8Ask the customer about the conditions and the
environment when the problem occurred.1
Confirm the symptoms and the problem conditions,
and check the diagnostic trouble codes.
(When the problem symptoms do not appear
during confirmation, use the symptom simulation
method described later.)2, 3
Check the results obtained in Step 2, then confirm
the inspection procedure for the system or the part
which should be checked using the diagnostic
trouble code chart or the problem symptoms table.4, 5, 6
Check and repair the affected system or part in
accordance with the instructions in Step 6. 7
After completing repairs, confirm that the problem
has been eliminated.
(If the problem is not reproduced, perform the
confirmation test under the same conditions and
in the same environment as when it occurred for
the first time.)8
IN±24± INTRODUCTIONHOW TO TROUBLESHOOT ECU CONTROLLED
SYSTEMS
24 Author: Date:
2005 SEQUOIA (RM1146U)
HOW TO PROCEED WITH TROUBLESHOOTING
Carry out troubleshooting in accordance with the procedure on the following page. Here, only the basic pro-
cedure is shown. Details are provided in Diagnostics section, showing the most effective methods for each
circuit. Confirm the troubleshooting procedures first for the relevant circuit before beginning troubleshooting
of that circuit.

Important Points in the Customer Problem Analysis
 What ±±±±± Vehicle model, system name
 When ±±±±± Date, time, occurrence frequency
 Where ±±±±± Road conditions
 Under what conditions? ±±±±± Running conditions, driving conditions, weather conditions
 How did it happen? ±±±±± Problem symptoms
(Sample) Engine control system check sheet.
ENGINE CONTROL SYSTEM Check Sheet
Customer's Name
Driver's Name
Data Vehicle
Brought in
License No.
Model and Model
Year
Frame No.
Engine Model
Odometer Reading
km
miles
Problem Symptoms
Engine does
not Start
Difficult to
Start
Poor Idling
Poor
Drive ability
Engine Stall
Others
Engine does not crankNo initial combustionNo complete combustion
Engine cranks slowly
Other
Incorrect first idleIdling rpm is abnormalHigh ( rpm)Low ( rpm)
Rough idling
Other
HesitationBack fireMuffler explosion (after±fire)Surging
Knocking
Other
Soon after startingAfter accelerator pedal depressed
After accelerator pedal released
During A/C operation
Shifting from N to D
Other
Data Problem
ConstantSometimes ( times per day/month)
Inspector's
Name
CUSTOMER PROBLEM ANALYSIS CHECK
± INTRODUCTIONHOW TO TROUBLESHOOT ECU CONTROLLED
SYSTEMSIN±25
25 Author: Date:
2005 SEQUOIA (RM1146U)
1. CUSTOMER PROBLEM ANALYSIS
In troubleshooting, the problem symptoms must be confirmed accurately and all preconceptions must be
cleared away in order to give an accurate judgment. To ascertain just what the problem symptoms are, it is
extremely important to ask the customer about the problem and the conditions at the time it occurred.
Important Point in the Problem Analysis:
The following 5 items are important points in the problem analysis. Past problems which are thought to be
unrelated and the repair history, etc. may also help in some cases, so as much information as possible should
be gathered and its relationship with the problem symptoms should be correctly ascertained for reference
in troubleshooting. A customer problem analysis table is provided in Diagnostics section for each system
for your use.