2001 TOYOTA SEQUOIA VSC system

IN0002
Example
± INTRODUCTIONREPAIR INSTRUCTIONS
IN±7
7 Author: Date:
2005 SEQUOIA (RM1146U)
(7) When checking continuity at the wire connector, in-
sert the tester probe carefully to prevent terminals
from bending.
(8) When using a vacuum gauge, never force the hose
onto a connector that is too large. Use a step±down
adapter for adjustment. Once the hose has been
stretched, it may leak air.
(m) Installation and removal of vacuum hose:
(1) When disconnecting vacuum hoses, use tags to
identify where they should be reconnected to.
(2) After completing a job, double check that the vacu-
um hoses are properly connected. A label under the
hood shows the proper layout.
(n) Bleeding of hydraulic brake booster system.
When repairing the hydraulic brake booster or ABS,
TRAC, VSC system, bleed the air out of the hydraulic
brake booster(See page BR±4).
(o) Unless otherwise stated, all resistance is measured at an
ambient temperature of 20°C (68°F). Because the resis-
tance may be outside specifications if measured at high
temperatures immediately after the vehicle has been run-
ning. Measurement should be made when the engine has
cooled down.

F09750
DLC3
Ts
CG
± INTRODUCTIONFOR ALL OF VEHICLES
IN±17
17 Author: Date:
2005 SEQUOIA (RM1146U)
(i) AIRBAG SENSOR ASSEMBLY
(1) Never reuse the airbag sensor assembly involved
in a collision when the SRS has deployed.
(2) The connectors to the airbag sensor assembly
should be connected or disconnected with the sen-
sor mounted on the floor. If the connectors are con-
nected or disconnected while the airbag sensor as-
sembly is not mounted to the floor, it could cause
undesired ignition of the supplemental restraint sys-
tem.
(3) 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, even if only loosening the
set bolts of the airbag sensor assembly.
(j) WIRE HARNESS AND CONNECTOR
The SRS wire harness is integrated with the cowl wire har-
ness assembly and floor wire harness assembly. All the
connectors for the system are also a standard yellow col-
or. If the SRS wire harness becomes disconnected or the
connector becomes broken due to an accident, etc., re-
pair or replace it.
2. FOR VEHICLES EQUIPPED WITH VEHICLE SKID
CONTROL (VSC) SYSTEM
NOTICE:

Even if TRAC is initially OFF, it automatically be-
comes ON when the vehicle speed becomes about 30
km/h (19 mh) or more. Therefore, please drive in the
test mode to avoid dangerous situations caused by
the TRAC control.

VSC/ABS may be failed when the vehicle is driven on
the two±wheel chassis dynamo. Therefore, after driv-
ing on the chassis dynamo, please clear DTC before
normal driving. Please refer to the page DI±899 for the
method of clearing DTC.

Fasten the vehicle with the lock chain.
(a) Confirm VSC system is OFF.
(1) Turn the ignition switch OFF.
(2) Using SST, connect terminals Ts and CG of DLC3.
SST 09843±18040
(3) Start the engine.

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.

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.

IN±44
± INTRODUCTIONTERMS
44 Author: Date:
2005 SEQUOIA (RM1146U) T/M
Transmission
TMCTOYOTA Motor Corporation
TMMKTOYOTA Motor Manufacturing Kentucky, Inc.
TRCTraction Control System
TURBOTurbocharge
TWCThree±Way Catalyst
U/DUnderdrive
U/SUndersize
VCVVacuum Control Valve
VENTVentilator
VIMVehicle Interface Module
VINVehicle Identification Number
VPSVariable Power Steering
VSCVehicle Skid Control
VSVVacuum Switching Valve
VTVVacuum Transmitting Valve
VVT±iVariable Valve Timing±intelligent
W/With
WGNWagon
W/HWire Harness
W/OWithout
1STFirst
2NDSecond
2WDTwo Wheel Drive Vehicle (4 x 2)
3RDThird
4THFourth
4WDFour Wheel Drive Vehicle (4 x 4)
4WSFour Wheel Steering System
5THFifth

I18
Ignition
SW
A23552
ECM
STOPSTP
ALT
BatteryE4
16 G±Y
J/C1 S14 Stop Light SW
2
G±W
BR7
Stop
Light
LH
R8
Stop
Light
RH3
5
8W±R
A W
High
Mounted
Stop Light
W±B 1L
1 1F
7
F10
Fusible
Link
BlockInstrument
Panel J/B1
4EG±Y
4B8
Brake Inhibit Relay
G±Y 4
See VSC System 2
W
J19
J/CB
C
IC
CC
C
4
BD1
1
22
1H9 H9(*1)
(*2) (*1)(*2)
BD2
12 J/C
A1
4
G±W IG2
*1: w/o Rear Spoiler
*2: w/ Rear Spoiler AM2
To Towing
Converter Relay
W±BST1±
E4 15
4C 4A1
1
3
L±B Sub J/B No.4
2
IGN1 B±O2
4D2
4A
1E 17
2 1C
1 A
J44J11
J/C J10
J
J33
J34 C
3
IJ
52C
2D 11
AM2
B W±RB±R
6
Instrument
Panel J/B
BP1
4 G±W B±O
G±W
G±W G±WSub J/B No.4
J10
J45
4
BJ J57
J/CA
W±BW±B G±W
High
Mounted
Stop LightG±WJ20
J/C G±W H
Engine Room
J/B DI±284
± DIAGNOSTICSENGINE
478 Author: Date:
2005 SEQUOIA (RM1146U)
WIRING DIAGRAM

DIDLU±01
± DIAGNOSTICSABS WITH EBD & BA & TRAC & VSC SYSTEM
DI±891
1085 Author: Date:
2005 SEQUOIA (RM1146U)
ABS WITH EBD & BA & TRAC & VSC SYSTEM
PRECAUTION
NOTICE:
When disconnecting the battery terminal, initialize the following system after the terminal is recon-
nected.
System NameSee Page
Back Door Power Window Control SystemBE±77

When there is a malfunction in the contact point of the terminals or installation problems with
parts, removal and installation of the suspected problem parts may return the system to the
normal condition either completely or temporarily.

In order to determine the malfunctioning area, be sure to check the conditions at the time the
malfunction occurred, such as by DTC output and freeze frame data output, and record it before
disconnecting each connector or removing and installing parts.

Since the ABS with EBD & BA & TRAC & VSC systems may be influenced by a malfunction in
the other systems, be sure to check for DTCs in the other systems.

Be sure to remove and install the ABS & VSC actuator and each sensor with the IG switch OFF
unless specified in the inspection procedure.

When removing and installing the ABS & VSC actuator and each sensor, be sure to check that
the normal display is output in test mode inspection and in DTC output inspection after instal-
ling all the parts.

After replacing the yaw rate sensor and/or the ABS & VSC actuator assembly, make sure to per-
form yaw rate and deceleration sensors' zero point calibration
(See page DI±897).

The CAN communication system is used for data communication between the skid control ECU
(included in the actuator), the steering angle sensor, and the yaw rate sensor (the deceleration
sensor is included). If there is trouble in the CAN communication line, the DTC of the commu-
nication line is output.

If the DTC of the CAN communication line is output, repair the malfunction and troubleshoot
the ABS with EBD & BA & TRAC & VSC systems.

Since the CAN communication line has its own length and route, it can not be repaired tempo-
rarily with the bypass wire, etc.