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.
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 (Busline) 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
± INTRODUCTIONTERMS
IN±41
41 Author: Date:
2005 SEQUOIA (RM1146U) DC
Direct Current
DEFDefogger
DFLDeflector
DIFF.Differential
DIFF. LOCKDifferential Lock
D/INJDirect Injection
DLCData Link Connector
DLIDistributorless Ignition
DOHCDouble Overhead Camshaft
DPDash Pot
DSDead Soak
DSPDigital Signal Processor
DTCDiagnostic Trouble Code
DVDDigital Versatible Disc
EBDElectric Brake Force Distribution
ECElectrochoromic
ECAMEngine Control And Measurement System
ECDElectronically Controlled Diesel
ECDYEddy Current Dynamometer
ECTElectronic Control Transmission
ECUElectronic Control Unit
EDElectro±Deposited Coating
EDUElectronic Driving Unit
EDICElectric Diesel Injection Control
EFIElectronic Fuel Injection
E/GEngine
EGRExhaust Gas Recirculation
EGR±VMEGR±Vacuum Modulator
ELREmergency Locking Retractor
EMPSElectric Motor Power Steering
ENGEngine
ESAElectronic Spark Advance
ETCS±iElectronic Throttle Control System±intelligent
EVAPEvaporative Emission Control
EVPEvaporator
E±VRVElectric Vacuum Regulating Valve
EXExhaust
FEFuel Economy
FFFront±Engine Front±Wheel±Drive
F/GFuel Gauge
FIPGFormed In Place Gasket
FLFusible Link
F/PFuel Pump
FPUFuel Pressure Up
FRFront
F/WFlywheel
FW/DFlywheel Damper
FWDFront±Wheel±Drive
GASGasoline
GNDGround
GPSGlobal Positioning System
HACHigh Altitude Compensator
IN±42
± INTRODUCTIONTERMS
42 Author: Date:
2005 SEQUOIA (RM1146U) H/B
Hatchback
H±FUSEHigh Current Fuse
HIHigh
HIDHigh Intensity Discharge (Head Lamp)
HSGHousing
HTHard Top
HWSHeated Windshield System
ICIntegrated Circuit
IDIIndirect Diesel Injection
IFSIndependent Front Suspension
IGIgnition
IIAIntegrated Ignition Assembly
INIntake (Manifold, Valve)
INTIntermittent
I/PInstrument Panel
IRSIndependent Rear Suspension
ISCIdle Speed Control
J/BJunction Block
J/CJunction Connector
KDKick±Down
LANLocal Area Network
LBLiftback
LCDLiquid Crystal Display
LEDLight Emitting Diode
LHLeft±Hand
LHDLeft±Hand Drive
L/H/WLength, Height, Width
LLCLong±Life Coolant
LNGLiquified Natural Gas
LOLow
LPGLiquified Petroleum Gas
LSDLimited Slip Differential
LSP & PVLoad Sensing Proportioning And Bypass Valve
LSPVLoad Sensing Proportioning Valve
MAPManifold Absolute Pressure
MAX.Maximum
MICMicrophone
MILMalfunction Indicator Lamp
MIN.Minimum
MG1Motor Generator No.1
MG2Motor Generator No.2
MPMultipurpose
MPIMultipoint Electronic Injection
MPXMultiplex Communication System
M/T, MTMManual Transmission (Transaxle)
MTMount
MTGMounting
NNeutral
NANatural Aspiration
NO.Number
O2SOxygen Sensor
O/DOverdrive
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
IN±46
± INTRODUCTIONTERMS
46 Author: Date:
2005 SEQUOIA (RM1146U) IAC
Idle Air ControlIdle Speed Control (ISC)
IATIntake Air TemperatureIntake or Inlet Air Temperature
ICMIgnition Control Module±
IFIIndirect Fuel InjectionIndirect Injection (IDL)
IFSInertia Fuel±Shutoff±
ISCIdle Speed Control±
KSKnock SensorKnock Sensor
MAFMass AirflowAir Flow Meter
MAPManifold Absolute PressureManifold Pressure Intake Vacuum
MCMixture Control
Electric Bleed Air Control Valve (EBCV)
Mixture Control Valve (MCV)
Electric Air Control Valve (EACV)
MDPManifold Differential Pressure±
MFIMultiport Fuel InjectionElectronic Fuel Injection (EFI)
MILMalfunction Indicator LampCheck Engine Lamp
MSTManifold Surface Temperature±
MVZManifold Vacuum Zone±
NVRAMNon±Volatile Random Access Memory±
O2SOxygen SensorOxygen Sensor, O2 Sensor (O2S)
OBDOn±Board DiagnosticOn±Board Diagnostic System (OBD)
OCOxidation Catalytic ConverterOxidation Catalyst Convert (OC), CCo
OLOpen LoopOpen Loop
PAIRPulsed Secondary Air InjectionAir Suction (AS)
PCMPowertrain Control Module±
PNPPark/Neutral Position±
PROMProgrammable Read Only Memory±
PSPPower Steering Pressure±
PTOXPeriodic Trap OxidizerDiesel Particulate Filter (DPF)
Diesel Particulate Trap (DPT)
RAMRandom Access MemoryRandom Access Memory (RAM)
RMRelay Module±
ROMRead Only MemoryRead Only Memory (ROM)
RPMEngine SpeedEngine Speed
SCSuperchargerSupercharger
SCBSupercharger BypassE±ABV
SFISequential Multiport Fuel InjectionElectronic Fuel Injection (EFI), Sequential Injection
SPLSmoke Puff Limiter±
SRIService Reminder Indicator±
SRTSystem Readiness Test±
STScan Tool±
TBThrottle BodyThrottle Body
TBIThrottle Body Fuel InjectionSingle Point Injection
Central Fuel Injection (Ci)
TCTurbochargerTurbocharger
TCCTorque Converter ClutchTorque Converter
TCMTransmission Control ModuleTransmission ECU, ECT ECU