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.
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
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
MA003±50
MA±4
± MAINTENANCEUNDER HOOD
51 Author: Date:
2005 SEQUOIA (RM1146U)
UNDER HOOD
GENERAL MAINTENANCE
1. GENERAL NOTES
Maintenance items may vary from country to country. Check the owner's manual supplement in which
the maintenance schedule is shown.
Every service item in the periodic maintenance schedule must be performed.
Periodic maintenance service must be performed according to whichever interval in the periodic main-
tenance schedule occurs first, the odometer reading (miles) or the time interval (months).
Maintenance service after the last period should be performed at the same interval as before unless
otherwise noted.
Failure to do even one item can cause the engine to run poorly and increase exhaust emissions.
2. WINDSHIELD WASHER FLUID
Check that there is sufficient fluid in the tank.
3. ENGINE COOLANT LEVEL
Check that the coolant level is between the FULL and LOW lines on the see±through reservoir.
4. RADIATOR AND HOSES
(a) Check that the front of the radiator is clean and not blocked with leaves, dirt or bugs.
(2UZ±FE engine: See page CO±14)
(b) Check the hoses for cracks, kinks, rot or loose connections.
5. BATTERY ELECTROLYTE LEVEL
Check that the electrolyte level of all battery cells is between the upper and lower level lines on the case.
6. BRAKE AND CLUTCH FLUID LEVELS
Check that the brake and clutch fluid levels are near the upper level line on the see±through reservoirs.
7. ENGINE DRIVE BELTS
Check all drive belts for fraying, cracks, wear or oiliness.
8. ENGINE OIL LEVEL
Check the level on the dipstick with the engine turned off.
9. POWER STEERING FLUID LEVEL
(a) Check the level on the dipstick.
(b) The level should be in the HOT or COLD range depending on the fluid temperature.
10. AUTOMATIC TRANSMISSION FLUID LEVEL
(a) Park the vehicle on a level surface.
(b) With the engine idling and the parking brake applied, shift the selector into all positions from the P to
L, and then shift into the P position.
(c) Pull out the dipstick and wipe off the fluid with a clean rag. Re±insert the dipstick and check that the
fluid level is in the HOT range.
(d) Do this check with the fluid at normal driving temperature (70 ± 80°C, 158 ± 176°F).
HINT:
Wait until the engine cools down (approx. 30 min.) before checking the fluid level after extended driving at
high speeds, in hot weather, in heavy traffic or pulling a trailer.
11. EXHAUST SYSTEM
(a) Visually inspect for cracks, holes or loose supports.
(b) If any change in the sound of the exhaust or smell of the exhaust fumes is noticed, find the cause and
correct.
DID7Z±01
D13872
Hand±Held Tester
DLC3CAN VIM
BR3904
0.13 sec.0.13 sec.
ON
OFF DI±44
± DIAGNOSTICSENGINE
238 Author: Date:
2005 SEQUOIA (RM1146U)
CHECK MODE PROCEDURE
HINT:
Hand±held tester only:
Check mode has a higher sensitivity to detect malfunctions and
can detect malfunctions that normal mode cannot detect.
Check mode can also detect all the malfunctions that normal
mode can detect.
1. CHECK MODE PROCEDURE
(a) Make sure that the items below are true.
(1) Battery positive voltage 11 V or more
(2) Throttle valve fully closed
(3) Transmission in the P or N position
(4) A/C switched OFF
(b) Turn the ignition switch OFF.
(c) Connect the hand±held tester to the DLC3.
(d) Turn the ignition switch ON.
(e) Change the ECM to check mode with the hand±held tes-
ter. Enter the following menus: DIAGNOSIS / EN-
HANCED OBD II / CHECK MODE. Make sure the MIL
flashes as shown in the illustration.
NOTICE:
All DTCs and freeze frame data recorded will be erased if:
1) the hand±held tester is used to change the ECM from
normal mode to check mode or vice±versa; or 2) during
check mode, the ignition switch is turned from ON to ACC
or OFF.
(f) Start the engine. The MIL should turn off after the engine
starts.
(g) Simulate the conditions of the malfunction described by
the customer.
(h) After simulating the malfunction conditions, use the
hand±held tester diagnosis selector to check the DTC,
freeze frame data and other data.
(i) After checking the DTC, inspect the applicable circuit.
2. CLEAR DTC (Using the hand±held tester)
(a) Connect the OBD ll scan tool or the hand±held tester to
the DLC3.
(b) Turn the ignition switch ON.
(c) Erase DTCs and freeze frame data with the OBD II scan
tool (complying with SAE J1978) or the hand±held tester.
For the hand±held tester: 1) enter the following menus:
DIAGNOSIS / ENHANCED OBD II / DTC INFO / CLEAR
CODES; and 2) press YES. For the OBD II scan tool, see
its instruction manual.
DIDIJ±01
± DIAGNOSTICSAUTOMATIC TRANSMISSION
DI±517
711 Author: Date:
2005 SEQUOIA (RM1146U)
TOYOTA PART AND SYSTEM NAME LIST
This reference list indicates the part names used in this manual along with their definitions.
Part and system nameDefinition
Toyota HCAC system, Hydrocarbon adsorptive Catalyst
(HCAC) system, HC adsorptive three±way catalystHC adsorptive three±way catalytic converter
Variable Valve Timing sensor, VVT sensorCamshaft position sensor
Variable valve timing system, VVT systemCamshaft timing control system
Camshaft timing oil control valve, Oil control valve OCV,
VVT, VSVCamshaft timing oil control valve
Variable timing and lift, VVTLCamshaft timing and lift control
Crankshaft position sensor ºAºCrankshaft position sensor
Engine speed sensorCrankshaft position sensor
THAIntake air temperature
Knock control moduleEngine knock control module
Knock sensorEngine knock sensor
Mass or volume air flow circuitMass air flow sensor circuit
Vacuum sensorManifold air pressure sensor
Internal control module, Control module, Engine control
ECU, PCMPower train control module
FC idleDeceleration fuel cut
Idle air control valveIdle speed control
VSV for CCV, Canister close valve VSV for canister controlEvaporative emissions canister vent valve
VSV for EVAP, Vacuum switching valve assembly No. 1,
EVAP VAV, Purge VSVEvaporative emissions canister purge valve
VSV for pressure switching valve, Bypass VSVEvaporative emission pressure switching valve
Vapor pressure sensor, EVAP pressure sensor, Evaporative
emission control system pressure sensorFuel tank pressure sensor
Charcoal canisterEvaporative emissions canister
ORVR systemOn±board refueling vapor recovery system
Intake manifold runner controlIntake manifold tuning system
Intake manifold runner valve, IMRV, IACV (runner valve)Intake manifold tuning valve
Intake control VSVIntake manifold tuning solenoid valve
AFSAir fuel ratio sensor
O2 sensorHeater oxygen sensor
Oxygen sensor pumping current circuitOxygen sensor output signal
Oxygen sensor reference ground circuitOxygen sensor signal ground
Accel position sensorAccelerator pedal position sensor
Throttle actuator control motor, Actuator control motor, Elec-
tronic throttle motor, Throttle control motorElectronic throttle actuator
Electronic throttle control system, Throttle actuator control
systemElectronic throttle control system
Throttle/pedal position sensor, Throttle/pedal position switch,
Throttle position sensor/switchThrottle position sensor
Turbo press sensorTurbocharger pressure sensor
Turbo VSVTurbocharger pressure control solenoid valve
P/S pressure switchPower±steering pressure switch
VSV for ACMActive control engine mount
Speed sensor, Vehicle speed sensor ºAº, Speed sensor for
skid control ECUVehicle speed sensor
ATF temperature sensor, Trans. fluid temp. sensor, ATF
temperature sensor ºAºTransmission fluid temperature sensor
Electronic controlled automatic transmission, ECTElectronically controlled automatic
Intermediate shaft speed sensor ºAºCounter gear speed sensor
DIDIN±01
Vehicle Brought to Workshop
Customer Problem Analysis
Check DTC and Freeze Frame Data (Precheck)
Record or Print DTC and Freeze Frame Data DI±565
Clear DTC and Freeze Frame Data DI±565
Visual Inspection
Setting the Check Mode Diagnosis DI±566
1
Items insideare titles of pages in this manual, with the
page number indicated in the bottom portion. See the indicated
pages for detailed explanations.
DI±523
Connect a hand±held tester to DLC3.
If the display shows ºUNABLE TO CONNECT TO VEHICLEº when you have connected the
scan tool/hand±held tester, inspect DLC3 DI±562
2
3
4
5
6
Symptom does not occur
Problem Symptom Confirmation8
7Symptom Simulation
P.IN±24
Symptom occurs
DTC Check
DI±565OK Code
11Preliminary Check
DI±524
DTC Chart
DI±573
Mechanical System Test
DI±538 and DI±540
Manual Shifting Test
DI±542OK
OK
Chapter 1
(Electronic)Chapter 2
(On±Vehicle)
DI±553OKChapter 3
(Off±Vehicle)OK Matrix Chart of Problem Symptoms ± DI±553
Circuit
Inspection
NG
Parts Inspection
NG
NGNG
Identification of ProblemRepairConfirmation TestEnd
NG
NG
12
OK13
14
1516
17 9
10
DI±553DI±553
DI±576 to DI±691
18
O/D Main Switch Circuit Check
Shift Position L Switch Circuit Check DI±522
± DIAGNOSTICSAUTOMATIC TRANSMISSION
716 Author: Date:
2005 SEQUOIA (RM1146U)
HOW TO PROCEED WITH TROUBLESHOOTING
DIDIT±01
D11984
DI±542
± DIAGNOSTICSAUTOMATIC TRANSMISSION
736 Author: Date:
2005 SEQUOIA (RM1146U)
MANUAL SHIFTING TEST
1. MANUAL SHIFTING TEST
HINT:
With this test, it can be determined whether the trouble oc-
curs in the electrical circuit or is a mechanical problem in
the transmission.
If any abnormalities are found in the following test, the
problem is in the transmission itself.
(a) Disconnect the connector of the transmission wire.
(b) Drive with the transmission wire disconnected.
Shifting the shift lever to the L, 2, 3, 4 and D position to
check whether the shifting condition changes the table
below.
Shift PositionShifting Condition
L @2No Shift (Not Change)
2 @3Down Shift @Up Shift
3 @4Down Shift @Up Shift
4 @DNo Shift (Not Change)
HINT:
When driving with the transmission wire disconnected, the gear
position will be as follows:
When the shift lever is in the L or the 2 position, the gear
is held in the 1st position.
When the shift lever is in the 3rd position, the gear is held
in the 3rd position.
When the shift lever is in the 4 or the D position, the gear
is held in the 4th position.
When the shift lever is in the R or the P position, the gear
is also in the R or the P position respectively.
(c) Connect the connector of the transmission wire.
(d) Clear the DTC (See page DI±565).