2001 TOYOTA SEQUOIA relay

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.

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.

IN±32± INTRODUCTIONHOW TO TROUBLESHOOT ECU CONTROLLED
SYSTEMS
32 Author: Date:
2005 SEQUOIA (RM1146U)
5. PROBLEM SYMPTOMS TABLE
The suspected circuits or parts for each problem symptom are shown in the table below. Use this table to
troubleshoot the problem when a ºNormalº code is displayed in the diagnostic trouble code check but the
problem is still occurring. Numbers in the table indicate the inspection order in which the circuits or parts
should be checked.
HINT:
When the problem is not detected by the diagnostic system even though the problem symptom is present,
it is considered that the problem is occurring outside the detection range of the diagnostic system, or that
the problem is occurring in a system other than the diagnostic system.
Symptom
Suspect AreaSee page
Engine does not crank (Does not start)
No initial combustion (Does not start)
No complete combustion (Does not start)1. Starter and starter relay
1. ECM power source circuit
2. Fuel pump control circuit
3. Engine control module (ECM)
1. Starter signal circuit
2. Fuel pump control circuit1. Fuel pump control circuitDI±147
DI±151
IN±29
PROBLEM SYMPTOMS TABLE
1. Compression
2. Fuel pump control circuit 1. A/C signal circuit
2. Fuel pump control circuit 1. A/C signal circuit (Compressor circuit)
2. ECM power source circuit 1. Starter signal circuit
2. Fuel pump control circuit1. Starter signal circuit
2. Fuel pump control circuit
3. Compression
idling) High engine idle speed (Poor idling) Hot engine Cold engine (Difficult to start)Engine cranks normally (Difficult to start)
AC±88 DI±144
DI±151
EM±3 DI±151
 Problem Symptom Page
Indicates the page where the flow chart for each circuit
is located.
 Circuit Inspection, Inspection Order
Indicates the circuit which needs to be checked for each problem
symptom. Check in the order indicated by the numbers.
 Circuit or Part Name
Indicates the circuit or part which needs to be checked.
ST±2
ST±17
DI±144
DI±151
DI±144
DI±151

± INTRODUCTIONTERMS
IN±43
43 Author: Date:
2005 SEQUOIA (RM1146U) OEM
Original Equipment Manufacturing
OHCOverhead Camshaft
OHVOverhead Valve
OPTOption
ORVROn±board Refilling Vapor Recovery
O/SOversize
P & BVProportioning And Bypass Valve
PCSPower Control System
PCVPositive Crankcase Ventilation
PKBParking Brake
PPSProgressive Power Steering
PSPower Steering
PTOPower Take±Off
P/WPower Window
R & PRack And Pinion
RAMRandom Access Memory
R/BRelay Block
RBSRecirculating Ball Type Steering
R/FReinforcement
RFSRigid Front Suspension
RHRight±Hand
RHDRight±Hand Drive
RLYRelay
ROMRead Only Memory
RRRear
RRSRigid Front Suspension
RWDRear±Wheel Drive
SDNSedan
SENSensor
SICSStarting Injection Control System
SOCState Of Charge
SOHCSingle Overhead Camshaft
SPECSpecification
SPISingle Point Injection
SRSSupplemental Restraint System
SSMSpecial Service Materials
SSTSpecial Service Tools
STDStandard
STJCold±Start Fuel Injection
SWSwitch
SYSSystem
T/ATransaxle
TACHTachometer
TBIThrottle Body Electronic Fuel Injection
TCTurbocharger
TCCSTOYOTA Computer±Controlled System
TCVTiming Control Valve
TDCTop Dead Center
TEMP.Temperature
TEMSTOYOTA Electronic Modulated Suspension
TFTTOYOTA Free±Tronic
TISTotal Information System For Vehicle Development

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

PP0O2±06
± PREPARATIONBODY ELECTRICAL
PP±73
131 Author: Date:
2005 SEQUOIA (RM1146U)
EQUIPMENT
Voltmeter
Ammeter
Ohmmeter
Test lead
ThermometerEngine coolant temperature sender gauge, Engine oil level warn-
ing switch, Seat heater
SyphonBrake fluid level warning switch
Oil bathEngine oil level warning switch
Bulb (1.4 W)Defogger switch
Bulb (3.4 W)Fuel sender gauge, Engine coolant temperature receiver gauge,
Seat belt warning relay
Dry cell batteryFuel sender gauge, Power mirror
Heat lightSeat heater
Hexagon wrench (6 mm)Power seat
Torque wrench
Masking tapeRear window defogger wire
Tin foilRear window defogger wire

DID7Q±01
B17429
ECM
IG SW
IGSW
STSW
STAR/NSW
STA
BATT
MREL
+BM
+B
+B2
VCPA
VPA
EPA
VCP2
VPA2
EPA2W
OC1+
OC1±
OC2+
OC2±
KNK1
EKNK
KNK2
EKN2
G2+
G2±
NE+
NE±
VV1+
VV1±
VV2+
VV2± ETCSMIL
To Battery
To Battery
To Battery
To BatteryTo Starter ST Relay
PNP SW
EFI No.1
EFI No.1 Relay
Acclererator Pedal
Position SensorCombination Meter
VVT OCV
(Bank 1)
VVT OCV
(Bank 2)
Knock Sensor
(Bank 1)
Knock Sensor
(Bank 2)
Camshaft Position
SensorTo V C
Terminal
Crankshaft
Position Sensor
VVT Sensor
(Bank 1)
VVT Sensor
(Bank 2) DI±6
± DIAGNOSTICSENGINE
200 Author: Date:
2005 SEQUOIA (RM1146U)
SYSTEM DIAGRAM

B17430
HA1A
A1A+
A1A±
HA2A
A2A+
A2A±
HT1B
OXIB
HT2B
OX2B
E2
PRG
ACIS
AIV1
AIV2
THA
E2G
VG
E2
THW
PPMP
VPMP
MPMP#10
#20
#30
#40
#50
#60
#70
#80
IGT1
IGT2
IGT3
IGT4
IGT5
IGT6
IGT7
IGT8
IGF1
IGF2 To A/F Relay
A/F Sensor
(Bank 1 Sensor 1)
A/F Sensor
(Bank 2 Sensor 1)
HO2 Sensor
(Bank 1 Sensor 2)
HO2 Sensor
(Bank 2 Sensor 2) To EFI Relay
To EFI No.2
Fuse
VSV (EVAP)
VSV (ACIS)
VSV (AI Control)
VSV (AI Control)
Mass Air Flow
Meter
ETC Sensor
Pump Modul
Pressure
Sensor
Control
Valve To VC
TerminalTo Battery
IGN2
Fuel Injector #1
Fuel Injector #2
Fuel Injector #3
Fuel Injector #4
Fuel Injector #5
Fuel Injector #6
Fuel Injector #7
Fuel Injector #8
Ignition Coil and
Igniter No.1
Ignition Coil and
Igniter No.2
Ignition Coil and
Igniter No.3
Ignition Coil and
Igniter No.4
Ignition Coil and
Igniter No.5
Ignition Coil and
Igniter No.6
Ignition Coil and
Igniter No.7
Ignition Coil and
Igniter No.8
± DIAGNOSTICSENGINE
DI±7
201 Author: Date:
2005 SEQUOIA (RM1146U)