2001 TOYOTA SEQUOIA Fuel systems

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.

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

± DIAGNOSTICSENGINE
DI±55
249 Author: Date:
2005 SEQUOIA (RM1146U)DIST DTC CLEAR
Distance after DTC cleared:
Min.: 0 km/h, Max.: 65535 km/hEquivalent to drive distance after
DTCs were erased'
WU CYC DTC CLEARWarm±up cycle after DTC cleared:
Min.: 0, Max.: 255'Number of warm±up cycles after
DTC cleared
MODEL CODEModel code:'Identifying the model code:
UCK30 (2WD), UCK40 (4WD)
ENGINE TYPEEngine type:'Identifying the engine type:
2UZFE
CYLINDER NUMBERCylinder number:
Min.: 0, Max.: 255'Identifying the cylinder number:
8
TRANSMISSIONTransmission type:'Identifying the transmission type:
ECT(5AT)
DESTINATIONDestination'Identifying the destination:
A (America)
MODEL YEARModel year:
Min.: 0, Max.: 255'Identifying the model year:
200#
SYSTEMSystem identification'Identifying the engine system:
GASLIN (gasoline engine)
AI STATUSAI operation prohibit:
OK or NGOK
*1: If no idling conditions are specified, the transmission gear selector lever should be in the N or P position,
and the A/C switch and all accessory switches should be OFF.
2. ACTIVE TEST
HINT:
Performing an ACTIVE TEST enables components including the relays, VSV (Vacuum Switching Valve),
and actuators, to be operated without removing any parts. The ACTIVE TEST can be performed with a
hand±held tester. Performing an ACTIVE TEST as the first step of troubleshooting is one method of shorten-
ing diagnostic time.
DATA LIST can be displayed during ACTIVE TESTs.
(a) Connect a hand±held tester to the DLC3.
(b) Turn the ignition switch to ON.
(c) Turn the tester ON.
(d) Select the following menu items: DIAGNOSIS / ENHANCED OBD II / ACTIVE TEST.
(e) Perform the ACTIVE TEST by referring to the table below.
Hand±held Tester DisplaysTest DetailsControl RangesDiagnostic Notes
INJ VOLChange injection volumeBetween ±12 % and 25 %

All injectors tested at the same
time

Perform test at less than 3,000
rpm

Injection volume can be changed
in 1 % graduations within control
range
A/F CONTROLChange injection volumeLower by 12.5 % or increase by 25
%

Perform test at less than 3,000
rpm

A/F CONTROL enables checking
and graphing of A/F (Air Fuel Ra-
tio) sensor and Heated Oxygen
(HO2) sensor voltage outputs

To conduct test, select following
menu items: ACTIVE TEST / A/F
CONTROL / USER DATA / AFS
B1S1 and O2S B1S2, and press
YES and ENTER followed by F4
EVAP VSV (ALONE)Activate EVAP VSV controlON/OFF±

A15651
ECM
Intake Air Temp. Sensor
(Built into Mass Air Flow Meter)
54 Y±G5 V
THA 22R
E8
E8 G±W28
E2
E1 M1
THA
E2
± DIAGNOSTICSENGINE
DI±115
309 Author: Date:
2005 SEQUOIA (RM1146U)
WIRING DIAGRAM
INSPECTION PROCEDURE
HINT:

If DTCs related to different systems that have terminal E2 as the ground terminal are output simulta-
neously, terminal E2 may have an open circuit.

Read freeze frame data using the hand-held tester. Freeze frame data records the engine conditions
when a malfunction is detected. When troubleshooting, freeze frame data can help determine if the
vehicle was running or stopped, if the engine was warmed up or not, if the air±fuel ratio was lean or
rich, as well as other data from the time when a malfunction occurred.

EM±2
± ENGINE MECHANICALCO/HC
2581 Author: Date:
2005 SEQUOIA (RM1146U)
5. IMMEDIATELY CHECK CO/HC CONCENTRATION AT
IDLE AND/OR 2,500 RPM
HINT:
When performing the 2 mode (2,500 rpm and idle) test, follow
the measurement orders are prescribed by the applicable local
regulations.
If the CO/HC concentration does not comply with regulations,
perform troubleshooting in the order given below.
(a) Check the air±fuel ratio sensors and heated oxygen sen-
sors operation.(See page DI±88 and DI±93)
(b) See the table below for possible causes, and then inspect
and correct the applicable causes if necessary.
COHCProblemsCauses
NormalHighRough idle7. Faulty ignitions:

Incorrect timing

Fouled, shorted or improperly gapped plugs
8. Incorrect valve clearance
9. Leaky intake and exhaust valves
10.Leaky cylinders
LowHighRough idle
(fluctuating HC reading)1. Vacuum leaks:

PCV hoses

Intake manifold

Throttle body

Brake booster line
2. Lean mixture causing misfire
HighHighRough idle
(Black smoke from exhaust)1. Restricted air filter
2. Faulty SFI systems:

Faulty pressure regulator

Defective ECT sensor

Faulty ECM

Faulty injectors

Faulty throttle position sensor

Faulty MAF meter

EC087±03
± EMISSION CONTROLEMISSION CONTROL SYSTEM
EC±1
2709 Author: Date:
2005 SEQUOIA (RM1146U)
EMISSION CONTROL SYSTEM
PURPOSE
The emission control systems are installed to reduce the amount of HC, CO and NOx exhausted from the
engine ((3) and (4)), to prevent the atmospheric release of blow±by gas±containing HC (1) and evaporated
fuel containing HC being released from the fuel tank (2).
The function of each system is shown in these table:
SystemAbbreviationFunction
(1) Positive Crankcase Ventilation
(2) Evaporative Emission Control
(3) Three±Way Catalytic Converter
(4) Sequential Multiport Fuel Injection*PCV
EVAP
TWC
SFIReduces HC
Reduces evaporated HC
Reduces HC, CO and NOx
Injects a precisely timed, optimum amount of fuel for reduced exhaust
emissions
Remark: * For inspection and repair of the SFI system, refer to the SF section in this manual.

SF±8
± SFIFUEL PUMP
2742 Author: Date:
2005 SEQUOIA (RM1146U)
(h) Measure the fuel pressure.
Fuel pressure:
265 to 304 kPa (2.7 to 3.1 kgf/cm
2, 38 to 44 psi)
If pressure is high, replace the fuel pressure regulator.
If pressure is low, check the fuel hoses and connections, fuel
pump, fuel filter and fuel pressure regulator.
(i) Disconnect the hand±held tester and CAN VIM from the
DLC3.
(j) Start the engine.
(k) Measure the fuel pressure at idle.
Fuel pressure:
265 to 304 kPa (2.7 to 3.1 kgf/cm
2, 38 to 44 psi)
(l) Stop the engine.
(m) Check that the fuel pressure remains as specified for 5
minutes after the engine has stopped.
Fuel pressure: 147 kPa (1.5 kgf/cm
2, 21 psi) or more
If pressure is not as specified, check the fuel pump, pressure
regulator and/or injectors.
(n) After checking fuel pressure, disconnect the negative (±)
terminal cable from the battery and carefully remove the
SST to prevent gasoline from splashing.
SST 09268±45014
(o) Reinstall the front fuel pipe to the LH delivery pipe. (See
page SF±31)
3. CONNECT CABLE TO NEGATIVE BATTERY TERMI-
NAL
4. PERFORM INITIALIZATION (See page IN±20)
Some systems need initialization when disconnecting the cable
from the negative battery terminal.
5. CHECK FOR FUEL LEAKS (See page SF±1)

05_SEQUOIA_U (L/O 0408)
vii
2005 SEQUOIA from Aug. '04 Prod. (OM34424U)
Spark ignition system of your
To y o t a
The spark ignition system in your Toyota meets all re-
quirements of the Canadian Interference±Causing Equip-
ment Standard.
Installation of a mobile
two±way radio system
As the installation of a mobile two±way radio system in
your vehicle could affect electronic systems such as
multiport fuel injection system/sequential multiport fuel
injection system, electronic throttle control system,
cruise control system, anti±lock brake system, traction
control system (two±wheel drive models)/active traction
control system (four±wheel drive models), vehicle stabil-
ity control system, rear height control air suspension
system, tire pressure warning system, SRS airbag sys-
tem and seat belt pretensioner system, be sure to
check with your Toyota dealer for precautionary mea-
sures or special instructions regarding installation.