trouble shooting TOYOTA SEQUOIA 2001 Service Repair Manual

IN01O±10
N17080
Filler Cap
Float
Reservoir Tank
 Grommet
Clip
Slotted Spring Pin
: Specified torque
 Non±reusable partCylinder
Piston
Push Rod
Washer
Snap Ring
Boot
 Gasket
Lock Nut
Clevis Pin
Clevis
N´m (kgf´cm, ft´lbf)
12 (120, 9)
15 (155, 11)
± INTRODUCTIONHOW TO USE THIS MANUAL
IN±1
1 Author: Date:
2005 SEQUOIA (RM1146U)
HOW TO USE THIS MANUAL
GENERAL INFORMATION
1. INDEX
An INDEX is provided on the first page of each section to guide you to the item to be repaired. To assist you
in finding your way through the manual, the Section Title and major heading are given at the top of every
page.
2. GENERAL DESCRIPTION
At the beginning of each section, a General Description that pertains to all repair operations contained in
that section is given.
Read these precautions before starting any repair task.
3. TROUBLESHOOTING
TROUBLESHOOTING tables are included for each system to help you diagnose the problem and find the
cause. The fundamentals of how to proceed with troubleshooting are described on page IN±24.
Be sure to read this before performing troubleshooting.
4. PREPARATION
Preparation lists the SST (Special Service Tools), recommended tools, equipment, lubricant and SSM (Spe-
cial Service Materials) which should be prepared before beginning the operation and explains the purpose
of each one.
5. REPAIR PROCEDURES
Most repair operations begin with an overview illustration. It identifies the components and shows how the
parts fit together.
Example:

IN0IG±04
BO4111
Negative Cable
± INTRODUCTIONFOR ALL OF VEHICLES
IN±9
9 Author: Date:
2005 SEQUOIA (RM1146U)
FOR ALL OF VEHICLES
PRECAUTION
1. FOR VEHICLES EQUIPPED WITH SRS AIRBAG AND
SEAT BELT PRETENSIONER
(a) The SEQUOIA is equipped with an SRS (Supplemental
Restraint System), such as the driver airbag, front pas-
senger airbag, side airbag assembly, curtain shield airbag
assembly and seat belt pretensioner.
Failure to carry out service operations in the correct se-
quence could cause the supplemental restraint system to
unexpectedly deploy during servicing, possibly leading to
a serious accident.
Further, if a mistake is made in servicing the supplemental
restraint system, it is possible the SRS may fail to operate
when required. Before servicing (including removal or
installation of parts, inspection or replacement), be sure
to read the following items carefully, then follow the cor-
rect procedure described in this manual.
(b) GENERAL NOTICE
(1) Malfunction symptoms of the supplemental re-
straint system are difficult to confirm, so the diag-
nostic trouble codes become the most important
source of information when troubleshooting. When
troubleshooting the supplemental restraint system,
always inspect the diagnostic trouble codes before
disconnecting the battery (See page DI±1118).
(2) Work must be started after 90 seconds from the
time the ignition switch is turned to the ºLOCKº posi-
tion and the negative (±) terminal cable is discon-
nected from the battery.
(The supplemental restraint system is equipped
with a back±up power source because if work is
started within 90 seconds of disconnecting the neg-
ative (±) terminal cable from the battery, the SRS
may deploy.)
When the negative (±) terminal cable is discon-
nected from the battery, memory of the clock and
audio systems will be cancelled. So before starting
work, make a record of the contents memorized in
each memory system. When work is finished, reset
the clock and audio systems as before. To avoid
erasing the memory of each memory system, never
use a back±up power supply from another battery.

IN±10
± INTRODUCTIONFOR ALL OF VEHICLES
10 Author: Date:
2005 SEQUOIA (RM1146U)
(3) Even in case of a minor collision where the SRS
does not deploy, the steering wheel pad, the pas-
senger airbag assembly, side airbag assembly, cur-
tain shield airbag assembly, seat belt pretensioner,
airbag sensor assembly, front airbag sensor, side
airbag sensor assembly and curtain shield airbag
sensor assembly should be inspected.
Parts of referenceSee page
Steering wheel padSee page RS±22
Passenger side airbag assemblySee page RS±35
Side airbag assembly
Power adjuster type
Manual adjuster type
See page RS±49
See page RS±64
Curtain shield airbag assemblySee page RS±72
Seat belt pretensionerSee page BO±165
Airbag sensor assemblySee page RS±83
Front airbag sensor assemblySee page RS±88
Side airbag sensor assemblySee page RS±93
Curtain shield airbag sensor assemblySee page RS±98
(4) Never use SRS parts from another vehicle. When
replacing parts, replace them with new ones.
(5) Before repairs, remove the airbag sensor because
shocks are likely to be applied to the sensor during
repairs.
(6) Never disassemble or repair the steering wheel
pad, front passenger airbag assembly, airbag sen-
sor assembly and front airbag sensor.
(7) If the steering wheel pad, front passenger airbag
assembly, side airbag assembly, curtain shield air-
bag assembly, seat belt pretensioner, airbag sensor
assembly and front airbag sensor have been
dropped, or if there are cracks, dents or other de-
fects in the case, bracket or connector, replace
them with new ones.
(8) Do not expose the steering wheel pad, front pas-
senger airbag assembly, side airbag assembly, cur-
tain shield airbag assembly, seat belt pretensioner,
airbag sensor assembly and front airbag sensor di-
rectly to hot air or flames.
(9) Use a volt/ohmmeter with high impedance (10 kW/V
minimum) for troubleshooting of the electrical cir-
cuit.
(10) Information labels are attached to the periphery of
the SRS components. Follow the instructions on the
notices.
(11) After work on the supplemental restraint system is
completed, check the SRS warning light (See page
DI±1118).

IN0KL±01
± INTRODUCTIONFOR ALL OF VEHICLES
IN±21
21 Author: Date:
2005 SEQUOIA (RM1146U)
CUSTOMIZE PARAMETERS
HINT:
The following items can be customized.
NOTICE:

When a customer requests a change in a function, first make sure that customization of the
function(s) is/are possible.

Be sure to make a note of the current setting before customizing.

When troubleshooting a function, first make sure that the function is not set to OFF.

When troubleshooting, pay attention as there is a possibility that the function has been set to
SMALL through customizing (Example: In case of the symptom in which ºThe key reminder
buzzer operation does not functionº is displayed, check that the key reminder buzzer operation
is not set to SMALL, then perform troubleshooting).
METER:
DISPLAY (ITEM)DEFAULTCONTENTSSETTING
KEY REMND VOLUM
(Key reminder buzzer vol-
ume)
LARGEFunction that changes the volume of key reminder buzzer.LARGE/MEDIUM/SMALL
WIRELESS DOOR LOCK:
DISPLAY (ITEM)DEFAULTCONTENTSSETTING
WIRELESS OPERONTurns wireless door lock function ON/OFF.ON/OFF
OPEN DOOR WARNONSounds buzzer for 10 seconds when door is not completely
closed and transmitter LOCK switch is pressed.ON/OFF
AUTO LOCK DELAY30SControls amount of time from when doors are unlocked until
they are locked by automatic lock function.60S/30S
UNLOCK/2OPERON
When UNLOCK switch is pressed once, this function un±
locks only the designated door. When unlock switch is
pressed again within 3 seconds, all doors unlock. If setting is
OFF, pressing UNLOCK switch once unlocks all doors.
ON/OFF
LNT/LGT ON/UNLKONTurns on room light when wireless door lock system is oper-
ated.ON/OFF
ALARM FUNCTIONONOperates theft deterrent system when transmitter LOCK
(PANIC) switch is held for 3 seconds.ON/OFF
AUTO LOCKOFFLocks doors when the vehicle speed reaches a certain level.ON/OFF
UNLK/KEY TWICEON
Unlocks only driver's door when driver's door key cylinder is
turned to unlock once, and unlocks all doors when it is turned
to unlock twice. In OFF setting, unlocks all doors when the
cylinder is turned to unlock once.
ON/OFF
ALL UNLK/OPN±CLOFFFunction that unlocks all doors when the driver door is
opened after turning the ignition switch off.ON/OFF
UNLOCK/PARKOFFUnlocks doors when shift lever is moved to P position from
any position other than P while the ignition switch is ON.ON/OFF
THEFT:
DISPLAY (ITEM)DEFAULTCONTENTSSETTING
WARNING TIME15SChanges warning time for PASSIVE MODE.5S/15S/27.5S/60S
PASSIVE MODEOFF
Switches theft deterrent system from arming preparation
state to armed state 30 seconds after key is removed from
ignition key cylinder and driver side door is closed, even if
doors are not locked by wireless or door key lock operation.
ON/OFF
WARN BY GLS SENONFunction that switches the alarm warning on/off when glass
breakage is detected.ON/OFF

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.

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.

Diagnostic trouble code check
Making a note of and clearing of the diagnostic trouble codes displayed
Symptom confirmation
No problem symptoms
exist Problem symptoms
exist
Simulation test using the symptom
simulation methods
 Normal code displayed
 Problem symptoms exist Normal code displayed
 No problem symptoms exist Diagnostic trouble code check
Troubleshooting of problem indicated
by diagnostic trouble code Diagnostic trouble code displayed
 Problem symptoms exist
System Normal Troubleshooting of each
problem symptom
If a diagnostic trouble code was
displayed in the initial diagnostic
trouble code check, it indicates
that the trouble may have occurred
in a wire harness or connector in
that circuit in the past. Therefore,
check the wire harness and con-
nectors (See page IN±35).
IN±28± INTRODUCTIONHOW TO TROUBLESHOOT ECU CONTROLLED
SYSTEMS
28 Author: Date:
2005 SEQUOIA (RM1146U)
Taking into account the above points, a flow chart showing how to proceed with troubleshooting using the
diagnostic trouble code check is shown below. This flow chart shows how to utilize the diagnostic trouble
code check effectively, then by carefully checking the results, indicates how to proceed either to diagnostic
trouble code troubleshooting or to troubleshooting of problem symptoms table.

V07268
VIBRATION METHOD: When vibration seems to be the major cause.
CONNECTORS
WIRE HARNESS
PARTS AND SENSOR1
Slightly shake the connector vertically and horizontally.
Slightly shake the wire harness vertically and horizontally.
The connector joint, fulcrum of the vibration, and body
through portion are the major areas to be checked thorough-
ly.
Apply slight vibration with a finger to the part of the sensor
considered to be the problem cause and check that the mal-
function occurs.Shake Slightly
Swing Slightly
Vibrate Slightly
HINT:
Applying strong vibration to relays may result in open relays.
± INTRODUCTIONHOW TO TROUBLESHOOT ECU CONTROLLED
SYSTEMSIN±29
29 Author: Date:
2005 SEQUOIA (RM1146U)
3. SYMPTOM SIMULATION
The most difficult case in troubleshooting is when there are no problem symptoms occurring. In such cases,
a thorough customer problem analysis must be carried out, then simulate the same or similar conditions and
environment in which the problem occurred in the customer's vehicle. No matter how much experience a
technician has, or how skilled he may be, if he proceeds to troubleshoot without confirming the problem
symptoms he will tend to overlook something important in the repair operation and make a wrong guess
somewhere, which will only lead to a standstill. For example, for a problem which only occurs when the en-
gine is cold, or for a problem which occurs due to vibration caused by the road during driving, etc., the prob-
lem can never be determined so long as the symptoms are confirmed with the engine hot or the vehicle at
a standstill. Since vibration, heat or water penetration (moisture) is likely cause for problem which is difficult
to reproduce, the symptom simulation tests introduced here are effective measures in that the external
causes are applied to the vehicle in a stopped condition.
Important Points in the Symptom Simulation Test:
In the symptom simulation test, the problem symptoms should be confirmed, but the problem area or parts
must also be found out. To do this, narrow down the possible problem circuits according to the symptoms
before starting this test and connect a tester beforehand. After that, carry out the symptom simulation test,
judging whether the circuit being tested is defective or normal and also confirming the problem symptoms
at the same time. Refer to the problem symptoms table for each system to narrow down the possible causes
of the symptom.