2001 TOYOTA SEQUOIA spark plugs

MA004±18
P08488
Back Front
± MAINTENANCEENGINE
MA±5
52 Author: Date:
2005 SEQUOIA (RM1146U)
ENGINE
INSPECTION
HINT:
Perform the following procedures when the engine is cold.
1. REPLACE TIMING BELT
(See page EM±13)
2. INSPECT DRIVE BELT
(See page CH±1)
3. REPLACE SPARK PLUGS
(See page IG±1)
4. INSPECT AIR FILTER
(a) Visually check that the air cleaner element is not exces-
sively dirty, damaged or oily.
HINT:
Oiliness may indicate a stuck PCV valve.
If necessary, replace the air cleaner element.
(b) Clean the element with compressed air.
First blow from back side thoroughly, then blow off the
front side of the element.
5. REPLACE AIR FILTER
Replace the used air cleaner element with a new one.
6. REPLACE ENGINE OIL AND OIL FILTER
(See page LU±2)
7. REPLACE ENGINE COOLANT
(See page CO±2)
8. INSPECT CHARCOAL CANISTER
(See page EC±9)
9. REPLACE GASKET IN FUEL TANK CAP
(See page SF±33)
10. INSPECT FUEL LINES, CONNECTIONS, FUEL TANK
VAPOR VENT SYSTEM HOSES AND FUEL TANK
BAND
Visually inspect the fuel lines for cracks, leakage loose connec-
tions, deformation or tank band looseness.
11. INSPECT EXHAUST PIPES AND MOUNTINGS
Visually inspect the pipes, hangers and connections for severe
corrosion, leaks or damage.
12. INSPECT VALVE CLEARANCE
(See page EM±4)

B17396
HT +B
AF± AF+ Sensor 1A/F Sensor Component Side:
Front View
DI±174
± DIAGNOSTICSENGINE
368 Author: Date:
2005 SEQUOIA (RM1146U)
9 Check for spark and ignition (See page IG±1).
HINT:
If the spark plugs or ignition system malfunction, engine misfire may occur. The misfire counter can be read
with the hand±held tester. Enter the following menus: DIAGNOSIS / ENHANCED OBD II / DATA LIST / MIS-
FIRE / CYL#1 (to CYL#8).
NG Repair or replace ignition system.
OK
10 Check injector injection (See page SF±29).
HINT:
If the injectors malfunction, engine misfires may occur. The misfire counter can be read with the hand±held
tester. Enter the following menus: DIAGNOSIS / ENHANCED OBD II / DATA LIST / MISFIRE / CYL#1 (to
CYL#8).
NG Replace injector.
OK
11 Check resistance of air±fuel ratio (A/F) sensor heater.
PREPARATION:
Disconnect the air±fuel ratio (A/F) sensor connector.
CHECK:
Measure resistance between the terminals of the A/F sensor
connector.
OK:
Standard:
Tester ConnectionSpecified Condition
HT (1) ± +B (2)1.8 to 3.4 W at 20C (68F)
HT (1) ± AF± (4)10 kW or higher
NG Replace air±fuel ratio (A/F) sensor.
OK

A21429
ECM
No.1 Ignition Coil with Igniter
No. 2 Ignition
Coil with Igniter Crankshaft
Position
Sensor
Camshaft
Position
Sensor
Other Sensors:
No. 3 Ignition
Coil with Igniter
No. 4 Ignition
Coil with Igniter
No. 5 Ignition
Coil with Igniter
No. 6 Ignition
Coil with Igniter
No. 7 Ignition
Coil with Igniter
No. 8 Ignition
Coil with Igniter
TA C
To TachometerFrom Battery
Igniter
Ignition CoilSpark Plug
No. 1 Cylinder
No. 4 Cylinder
No. 5 Cylinder
No. 6 Cylinder No. 2 Cylinder
No. 3 Cylinder
No. 7 Cylinder
No. 8 Cylinder IGT1
IGF1
IGT2
IGF2
IGT3
IGT4
IGT5
IGT6
IGT7
IGT8 (Engine Coolant Temp.
Sensor, Mass Air Flow
Sensor, Throttle Position
Sensor, etc.)
DI±222
± DIAGNOSTICSENGINE
416 Author: Date:
2005 SEQUOIA (RM1146U)
CIRCUIT DESCRIPTION
These DTCs indicate a malfunction related to primary circuit.
The DIS is a 1±cylinder ignition system which ignites one cylinder with one ignition coil. In the 1±cylinder
ignition system, the one spark plug is connected to the end of the secondary winding. High voltage generated
in the secondary winding is applied directly to the spark plug. The spark of the spark plug passes from the
center electrode to the ground electrode.
The ECM determines the ignition timing and outputs the ignition signals (IGTs) for each cylinder. Using the
IGT, the ECM turns on and off the power transistor inside the igniter and this switches on and off the current
to the primary coil. When the current to the primary coil is cut off, high±voltage is generated in the secondary
coil and this voltage is applied to the spark plugs to create sparks inside the cylinders. As the ECM cuts the
current to the primary coil, the igniter sends back the ignition confirmation signal (IGF) for each cylinder igni-
tion to the ECM.

EM0KR±10
A04458
Compression
Gauge
± ENGINE MECHANICALCOMPRESSION
EM±3
2582 Author: Date:
2005 SEQUOIA (RM1146U)
COMPRESSION
INSPECTION
HINT:
If there is lack of power, excessive oil consumption or poor fuel
economy, measure the compression pressure.
1. WARM UP AND STOP ENGINE
Allow the engine to warm up to normal operating temperature.
2. REMOVE SPARK PLUGS (See page IG±1)
3. CHECK CYLINDER COMPRESSION PRESSURE
(a) Insert a compression gauge into the spark plug hole.
(b) Fully open the throttle.
(c) While cranking the engine, measure the compression
pressure.
HINT:
Always use a fully charged battery to obtain engine speed of
250 rpm or more.
(d) Repeat steps (a) through (c) for each cylinder.
NOTICE:
This measurement must be done in as short a time as pos-
sible.
Compression pressure:
1,373 kPa (14.0 kgf/cm
2, 199 psi) or more
Minimum pressure:
1,030 kPa (10.5 kgf/cm
2, 149 psi)
Difference between each cylinder:
98 kPa (1.0 kgf/cm
2, 14 psi) or less
(e) If the cylinder compression in one or more cylinders is low,
pour small amount of engine oil into the cylinder through
the spark plug hole and repeat steps (a) through (c) for
cylinders with low compression.

If adding oil helps the compression, chances are
that the piston rings and/or cylinder bore are worn
or damaged.

If pressure stays low, a valve may be sticking or
seating is improper, or there may be leakage past
the gasket.
4. REINSTALL SPARK PLUGS (See page IG±1)

A233435 mm Hexagon Wrench SST
B02642B02644A04229
RH Bank
LH Bank1
23 4
5 6
7
89
10
3
1 5
7 10
9 8
6 2
4
B02643
B02645A04230
Portion A
Portion A RH Bank
LH Bank
± ENGINE MECHANICALCYLINDER HEAD
EM±43
2622 Author: Date:
2005 SEQUOIA (RM1146U)
(e) Using SST and a 5 mm hexagon wrench, remove the 4
bolts, drive gear and oil seal.
SST 09960±10010 (09962±01000, 09963±00500)
NOTICE:
Be careful not to damage the timing tube.
27. REMOVE SPARK PLUGS
28. REMOVE CYLINDER HEAD AND EXHAUST MAN-
IFOLD ASSEMBLIES
(a) Uniformly loosen the 10 cylinder head bolts on one side
of each cylinder head in several steps, in the sequence
shown, then perform the same procedure to the other
side as shown. Remove the 20 cylinder head bolts and
plate washers.
NOTICE:

Cylinder head warpage or cracking could result from
removing bolts in incorrect order.

Do not drop the plate washer for cylinder head bolt
into portion A of the cylinder head. If dropped into
portion A, the plate washer will pass through the cyl-
inder head and cylinder block into the oil pan.

B02643
B02645A04230
RH Bank
LH BankPortion A
Portion A
A04093
Painted Mark
90°
90°
Front
A02888
Camshaft Gear Spring
Wave WasherCamshaft Sub±gear
A02861
EM±62
± ENGINE MECHANICALCYLINDER HEAD
2641 Author: Date:
2005 SEQUOIA (RM1146U)
NOTICE:
Do not drop the plate washer for cylinder head bolt into por-
tion A of the cylinder head. If dropped into portion A, the
plate washer will pass through the cylinder head and cylin-
der block into the oil pan.
(d) Mark the front of the cylinder head bolt with paint.
(e) Retighten the cylinder head bolts by 90° in the numerical
order shown.
(f) Check that the painted mark is now at a 90° angle to front.
5. INSTALL SPARK PLUGS
6. ASSEMBLE EXHAUST CAMSHAFT
(a) Install the camshaft gear spring, camshaft sub±gear and
wave washer.
HINT:
Attach the pin on the gear to the gear spring end.
(b) Using snap ring pliers, install the snap ring.

IG0MF±01
± IGNITIONIGNITION SYSTEM
IG±1
2862 Author: Date:
2005 SEQUOIA (RM1146U)
IGNITION SYSTEM
ON±VEHICLE INSPECTION
NOTICE:
ºColdº and ºHotº in these sentences express the tempera-
ture of the coils themselves. ºColdº is from ±10°C (14°F) to
50°C (122°F) and ºHotº is from 50°C (122°F) to 100°C
(212°F).
1. INSPECT IGNITION COIL (WITH IGNITER) AND
SPARK TEST
Check that the spark occurs.
(1) Remove the ignition coils (with igniter).
(see page IG±5)
(2) Remove the spark plugs.
(3) Install the spark plugs to each ignition coil (with ig-
niter), and connect the ignition coil (with igniter) con-
nector.
(4) Disconnect the 8 injector connectors.
(5) Ground the spark plug.
(6) Check that spark occurs while engine is being
cranked.
NOTICE:
To prevent gasoline from being injected out of injectors
during this test, crank the engine for no more than 5 to 10
seconds at a time.

SPARK TEST
Replace the crankshaft position sensor.
CHECK CONNECTION OF IGNITION COIL
CONNECTOR
CHECK RESISTANCE OF CRANKSHAFT POSITION
Resistance:Cold Hot
CHECK IGT SIGNAL FROM ECM
(See page DI±221)
REPAIR WIRING BETWEEN IGNITION COIL
AND ECM
Connect securely.
Check wiring between ignition switch
to ignition coil (with igniter).
Check ECM (See page IN±35)
NG
OK
OK
OKBAD
BAD
BAD
CHANGE IT TO NORMAL IGNITION COIL (WITH
IGNITER) AND PERFORM SPARK TEST AGAIN
OKReplace the ignition coil (with igniter).
NO
OK
985 ± 1,600 W1,265 ± 1,890 WBAD
CHECK POWER SUPPLY TO IGNITION COIL (WITH
1. Turn ignition switch to ON.
2. Check that there is battery voltage at ignition coil positive (+)
terminal.IGNITER)
CHECK TDC
NG
SENSOR (See page IG±12)
B03198
16 mm Plug Wrench
IG±2
± IGNITIONIGNITION SYSTEM
2863 Author: Date:
2005 SEQUOIA (RM1146U)
If the spark does not occur, do the test as follows:
(7) Using a 16 mm plug wrench, install the spark plugs.
Torque: 17.5 N´m (180 kgf´cm, 13 ft´lbf)
(8) Reinstall the ignition coils (with igniter).
(see page IG±6)
2. INSPECT SPARK PLUGS
(a) Remove the ignition coils (with igniter).
(see page IG±5)
(b) Using a 16 mm plug wrench, remove the spark plugs.