Page 19 of 4323
± 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.
Page 23 of 4323

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.
Page 45 of 4323

IN01X±04
± INTRODUCTIONTERMS
IN±45
45 Author: Date:
2005 SEQUOIA (RM1146U)
GLOSSARY OF SAE AND TOYOTA TERMS
This glossary lists all SAE±J1930 terms and abbreviations used in this manual in compliance with SAE rec-
ommendations, as well as their Toyota equivalents.
SAE
ABBREVIATIONSSAE TERMSTOYOTA TERMS
( )±±ABBREVIATIONS
A/CAir ConditioningAir Conditioner
ACLAir CleanerAir Cleaner, A/CL
AIRSecondary Air InjectionAir Injection (AI)
APAccelerator Pedal±
B+Battery Positive Voltage+B, Battery Voltage
BAROBarometric PressureHAC
CACCharge Air CoolerIntercooler
CARBCarburetorCarburetor
CFIContinuous Fuel Injection±
CKPCrankshaft PositionCrank Angle
CLClosed LoopClosed Loop
CMPCamshaft PositionCam Angle
CPPClutch Pedal Position±
CTOXContinuous Trap Oxidizer±
CTPClosed Throttle PositionLL ON, Idle ON
DFIDirect Fuel InjectionDirect Injection (DI/INJ)
DIDistributor Ignition±
DLC3Data Link Connector 3OBD II Diagnostic Connector
DTCDiagnostic Trouble CodeDiagnostic Trouble Code
DTMDiagnostic Test Mode±
ECLEngine Coolant Level±
ECMEngine Control ModuleEngine ECU (Electronic Control Unit)
ECTEngine Coolant TemperatureCoolant Temperature, Water Temperature (THW)
EEPROMElectrically Erasable Programmable Read Only Memory
Electrically Erasable Programmable Read Only Memory
(EEPROM),
Erasable Programmable Read Only Memory (EPROM)
EFEEarly Fuel EvaporationCold Mixture Heater (CMH), Heat Control Valve (HCV)
EGRExhaust Gas RecirculationExhaust Gas Recirculation (EGR)
EIElectronic IgnitionDistributorless Ignition (DLI)
EMEngine ModificationEngine Modification (EM)
EPROMErasable Programmable Read Only MemoryProgrammable Read Only Memory (PROM)
EVAPEvaporative EmissionEvaporative Emission Control (EVAP)
FCFan Control±
FEEPROMFlash Electrically Erasable Programmable
Read Only Memory±
FEPROMFlash Erasable Programmable Read Only Memory±
FFFlexible Fuel±
FPFuel PumpFuel Pump
GENGeneratorAlternator
GNDGroundGround (GND)
HO2SHeated Oxygen SensorHeated Oxygen Sensor (HO2S)
Page 46 of 4323

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
Page 65 of 4323
PP1BM±08
± PREPARATIONENGINE MECHANICAL
PP±7
65 Author: Date:
2005 SEQUOIA (RM1146U)
EQUIPMENT
Caliper gauge
CO/HC meter
Compression gauge
Connecting rod aligner
Cylinder gauge
Dial indicator
Dye penetrant
Engine tune±up tester
Groove cleaning tool
Heater
Magnetic finger
Micrometer
OBD II scan tool
Pin hole grinder
Piston ring compressor
Piston ring expander
Plastigage
Precision straight edge
Press
Ridge reamer
Soft brush
Solvent
Spring testerValve spring
Steel squareValve spring
Thermometer
Torque wrench
Valve seat cutter
Vernier calipers
V±block
Wire brushValve
Page 72 of 4323
PP0NI±09
PP±14
± PREPARATIONSFI
72 Author: Date:
2005 SEQUOIA (RM1146U)
EQUIPMENT
Graduated cylinderInjector
OBD II scan tool
Sound scopeInjector
Torque wrench
Vacuum gauge
Page 92 of 4323
PP42M±01
PP±34
± PREPARATIONAUTOMATIC TRANSMISSION (A750E, A750F)
92 Author: Date:
2005 SEQUOIA (RM1146U)
EQUIPMENT
OBD II scan tool
Torque wrench
CalipersTorque converter clutch
Straight edgeTorque converter clutch
Dial indicatorDrive plate runout
Page 203 of 4323

DI3H8±10
Vehicle Brought to Workshop
Customer Problem Analysis P. DI±10
Problem Symptom Confirmation
If the engine does not start perform steps 10 and 12 firstConnect the OBD II scan tool or hand±held tester to DLC3.
If the display indicates a communication fault in the tool, inspect DLC3 P.DI±40
Check DTC and Freeze Frame Data
Record or Print DTC and Freeze Frame Data P. DI±43
Clear DTC and Freeze Frame Data P. DI±43
Visual Inspection
Setting the Check Mode Diagnosis P. DI±44
Symptom Simulation P. IN±24
Basic Inspection P. DI±12DTC Chart P. DI±58
Problem Symptoms Table P. DI±33
Circuit Inspection P. DI±73
Adjustment, Repair
DTC Check P. DI±43
Items insideare titles of pages in
in the bottom portion. See the indicated
pages for detailed explanations. this manual, with the page number
Malfunction
occurs.Malfunction does not occur.
Parts Inspection
Check for Intermittent Problems P. DI±11
Identification of Problem
Confirmation Test
End 1
2
3
4
5
6
7
108
9
11
12
13
15 14
16
Normal Malfunction code.
17The hand±held tester can be used at
bold frame.
± DIAGNOSTICSENGINE
DI±9
203 Author: Date:
2005 SEQUOIA (RM1146U)
HOW TO PROCEED WITH TROUBLESHOOTING
Troubleshoot in accordance with the procedure on the following page.