2007 INFINITI QX56 spark plugs

EC-82
< SERVICE INFORMATION >
TROUBLE DIAGNOSIS
TROUBLE DIAGNOSIS
Trouble Diagnosis IntroductionINFOID:0000000003531617
INTRODUCTION
The engine has an ECM to control major systems such as fuel con-
trol, ignition control, idle air control system, etc. The ECM accepts
input signals from sensors and instantly drives actuators. It is essen-
tial that both input and output signals are proper and stable. At the
same time, it is important that there are no malfunctions such as vac-
uum leaks, fouled spark plugs, or other malfunctions with the engine.
It is much more difficult to diagnose an incident that occurs intermit-
tently rather than continuously. Most intermittent incidents are
caused by poor electric connections or improper wiring. In this case,
careful checking of suspected circuits may help prevent the replace-
ment of good parts.
A visual check only may not find the cause of the incidents. A road
test with CONSULT-II (or GST) or a circuit tester connected should
be performed. Follow the Work Flow on "WORK FLOW" .
Before undertaking actual checks, take a few minutes to talk with a
customer who approaches with a driveability complaint. The cus-
tomer can supply good information about such incidents, especially
intermittent ones. Find out what symptoms are present and under
what conditions they occur. A Diagnostic Worksheet like the example
on "Worksheet Sample" should be used.
Start your diagnosis by looking for conventional malfunctions first.
This will help troubleshoot driveability malfunctions on an electroni-
cally controlled engine vehicle.
WORK FLOW
MEF036D
SEF233G
SEF234G

EC-302
< SERVICE INFORMATION >
DTC P0172, P0175 FUEL INJECTION SYSTEM FUNCTION
7. If it is difficult to start engine at step 6, the fuel injection system has a malfunction, too.
8. Crank engine while depressing accelerator pedal.
If engine starts, go to EC-306, "
Diagnosis Procedure". If engine does not start, remove spark plugs and
check for fouling, etc.
WITH GST
1. Start engine and warm it up to normal operating temperature.
2. Turn ignition switch OFF and wait at least 10 seconds.
3. Disconnect mass air flow sensor harness connector. Then
restart and run engine for at least 5 seconds at idle speed.
4. Stop engine and reconnect mass air flow sensor harness con-
nector.
5. Select Service $03 with GST. Make sure DTC P0102 is
detected.
6. Select Service $04 with GST and erase the DTC P0102.
7. Start engine again and let it idle for at least 10 minutes.
8. Select Service $07 with GST. The 1st trip DTC P0172 or P0175
should be detected at this stage, if a malfunction exists. If so, go
to EC-306, "
Diagnosis Procedure".
NOTE:
If 1st trip DTC is not detected during above procedure, performing the following procedure is advised.
a. Turn ignition switch OFF and wait at least 10 seconds.
b. Start engine and drive the vehicle under the similar conditions to (1st trip) Freeze Frame Data for 10 min-
utes. Refer to the table below.
Hold the accelerator pedal as steady as possible.
The similar conditions to (1st trip) Freeze Frame Data means the vehicle operation that the following con-
ditions should be satisfied at the same time.
9. If it is difficult to start engine at step 7, the fuel injection system has a malfunction.
10. Crank engine while depressing accelerator pedal.
If engine starts, go to EC-306, "
Diagnosis Procedure". If engine does not start, remove spark plugs and
check for fouling, etc.
BBIA0368E
Engine speed Engine speed in the freeze frame data ± 400 rpm
Vehicle speed Vehicle speed in the freeze frame data ± 10 km/h (6 MPH)
Engine coolant temperature (T)
conditionWhen the freeze frame data shows lower than 70 °C (158 °F),
T should be lower than 70 °C (158 °F).
When the freeze frame data shows higher than or equal to 70 °C (158 °F),
T should be higher than or equal to 70 °C (158 °F).

EC-328
< SERVICE INFORMATION >
DTC P0300 - P0308 MULTIPLE CYLINDER MISFIRE, NO. 1 - 8 CYLINDER MIS-
FIRE
8. Crank engine for 5 seconds or more to remove combustion gas in the cylinder.
9. Connect spark plug and harness connector to ignition coil.
10. Fix ignition coil using a rope etc. with gap of 13 - 17 mm
between the edge of the spark plug and grounded metal portion
as shown in the figure.
11. Crank engine for about 3 seconds, and check whether spark is
generated between the spark plug and the grounded metal por-
tion.
CAUTION:
• Do not approach to the spark plug and the ignition coil
within 50cm. Be careful not to get an electrical shock
while checking, because the electrical discharge voltage
becomes 20kV or more.
• It might cause to damage the ignition coil if the gap of more than 17 mm is taken.
NOTE:
When the gap is less than 13 mm, the spark might be generated even if the coil is malfunctioning.
OK or NG
OK >> GO TO 9.
NG >> GO TO 6.
6.CHECK FUNCTION OF IGNITION COIL-II
1. Turn ignition switch OFF.
2. Disconnect spark plug and connect a known-good spark plug.
3. Crank engine for about 3 seconds, and recheck whether spark is generated between the spark plug and
the grounded metal portion.
OK or NG
OK >> GO TO 7.
NG >> Check ignition coil, power transistor and their circuits. Refer to EC-626
.
7.CHECK SPARK PLUG
Check the initial spark plug for fouling, etc.
OK or NG
OK >> Replace malfunctioning spark plug(s) with standard type
one(s). For spark plug type, refer to EM-29
.
NG >> 1. Repair or clean spark plug.
2. GO TO 8.
8.CHECK FUNCTION OF IGNITION COIL-III
1. Reconnect the initial spark plugs.
2. Crank engine for about 3 seconds, and recheck whether spark is generated between the spark plug and
the grounded portion.
OK or NG
OK >>INSPECTION END
NG >> Replace malfunctioning spark plug(s) with standard type one(s). For spark plug type, refer to EM-
29, "Removal and Installation".
9.CHECK COMPRESSION PRESSURESpark should be generated.
PBIB2325E
Spark should be generated.
SEF156I
Spark should be generated.

EC-352
< SERVICE INFORMATION >
DTC P0420, P0430 THREE WAY CATALYST FUNCTION
CAUTION:
Do the following procedure in the place where ventilation is good without the combustible.
1. Turn ignition switch OFF.
2. Remove fuel pump fuse in IPDM E/R to release fuel pressure.
NOTE:
Do not use CONSULT-II to release fuel pressure, or fuel pres-
sure applies again during the following procedure.
3. Start engine.
4. After engine stalls, crank it two or three times to release all fuel
pressure.
5. Turn ignition switch OFF.
6. Remove all ignition coil harness connectors to avoid the electri-
cal discharge from the ignition coils.
7. Remove ignition coil and spark plug of the cylinder to be
checked.
8. Crank engine for 5 seconds or more to remove combustion gas in the cylinder.
9. Connect spark plug and harness connector to ignition coil.
10. Fix ignition coil using a rope etc. with gap of 13 - 17 mm
between the edge of the spark plug and grounded metal portion
as shown in the figure.
11. Crank engine for about 3 seconds, and check whether spark is
generated between the spark plug and the grounded metal por-
tion.
CAUTION:
• Do not approach to the spark plug and the ignition coil
within 50cm. Be careful not to get an electrical shock
while checking, because the electrical discharge voltage
becomes 20kV or more.
• It might cause to damage the ignition coil if the gap of more than 17 mm is taken.
NOTE:
When the gap is less than 13 mm, the spark might be generated even if the coil is malfunctioning.
OK or NG
OK >> GO TO 10.
NG >> GO TO 7.
7.CHECK FUNCTION OF IGNITION COIL-II
1. Turn ignition switch OFF.
2. Disconnect spark plug and connect a known-good spark plug.
3. Crank engine for about 3 seconds, and recheck whether spark is generated between the spark plug and
the grounded metal portion.
OK or NG
OK >> GO TO 8.
NG >> Check ignition coil, power transistor and their circuits. Refer to EC-626
.
8.CHECK SPARK PLUGSpark should be generated.
BBIA0380E
PBIB2325E
Spark should be generated.

DTC P0420, P0430 THREE WAY CATALYST FUNCTION
EC-353
< SERVICE INFORMATION >
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Check the initial spark plug for fouling, etc.
OK or NG
OK >> Replace malfunctioning spark plug(s) with standard type
one(s). For spark plug type, refer to EM-29, "
Removal
and Installation".
NG >> 1. Repair or clean spark plug.
2. GO TO 9.
9.CHECK FUNCTION OF IGNITION COIL-III
1. Reconnect the initial spark plugs.
2. Crank engine for about three seconds, and recheck whether spark is generated between the spark plug
and the grounded portion.
OK or NG
OK >>INSPECTION END
NG >> Replace malfunctioning spark plug(s) with standard type one(s). For spark plug type, refer to EM-
29, "Removal and Installation".
10.CHECK FUEL INJECTOR
1. Turn ignition switch OFF.
2. Remove fuel injector assembly.
Refer to EM-31
.
Keep fuel hose and all fuel injectors connected to fuel injector gallery.
3. Disconnect all ignition coil harness connectors.
4. Reconnect all fuel injector harness connectors disconnected.
5. Turn ignition switch ON.
Make sure fuel does not drip from fuel injector.
OK or NG
OK (Does not drip.)>>GO TO 11.
NG (Drips.)>>Replace the fuel injector(s) from which fuel is dripping.
11 .CHECK INTERMITTENT INCIDENT
Refer to EC-138
.
Trouble is fixed.>>INSPECTION END
Trouble is not fixed.>>Replace three way catalyst assembly.
SEF156I
Spark should be generated.

CYLINDER HEAD
EM-69
< SERVICE INFORMATION >
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8. Install the valve collet using Tool.
CAUTION:
When working, take care not to damage valve lifter holes.
9. Install the valve lifters.
• Install the removed parts in their original locations.
• If installing new lifters, select the correct size lifter for proper valve clearance. Refer to EM-56, "
Va l v e
Clearance".
10. Install the spark plug tube if necessary, following the procedure below.
a. Remove any old liquid gasket adhering to the cylinder-head spark plug tube hole.
b. Apply liquid gasket to area within approximately 12 mm (0.47 in) from the edge of the spark plug tube
press-fit side.
Use Genuine RTV Silicone Sealant or equivalent. Refer to GI-45, "
Recommended Chemical Prod-
uct and Sealant".
c. Press-fit the spark plug tube to the specified height “H” using
suitable tool.
CAUTION:
• When press-fitting, take care not to deform the spark plug
tube.
• After press-fitting, wipe off any liquid gasket protruding
onto the cylinder-head upper face.
11. Install the spark plugs.
Inspection After DisassemblyINFOID:0000000003531543
CYLINDER HEAD DISTORTION
1. Remove any oil, scale, gasket, sealant and carbon deposits from the cylinder head surface.
CAUTION:
Do not allow any debris to enter the oil or coolant passages.
2. Measure the bottom surface of the cylinder head for distortion in
six directions as shown, using suitable tools.
• If measurement exceeds the limit, replace the cylinder head.
VALVE DIMENSIONS
Tool number : KV10116200 (J-26336-A)
: KV10115900 (J-26336-20)
: KV10109220 ( — )
WBIA0578E
Standard press-fit height “H” :38.4 - 39.4 mm
(1.512 - 1.551 in)
KBIA1248E
Standard : 0.03 mm (0.0012 in)
Limit : 0.1mm (0.004 in)
PBIC0075E

MA-1
MAINTENANCE
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CONTENTS
MAINTENANCE
SERVICE INFORMATION ............................2
PRECAUTIONS ...................................................2
Precaution for Supplemental Restraint System
(SRS) "AIR BAG" and "SEAT BELT PRE-TEN-
SIONER" ...................................................................
2
PREPARATION ...................................................3
Special Service Tool .................................................3
Commercial Service Tool ..........................................3
GENERAL MAINTENANCE ................................4
General Maintenance ................................................4
PERIODIC MAINTENANCE ................................6
Introduction of Periodic Maintenance ........................6
Maintenance for Off-road Driving (4WD only) ...........6
Schedule 1 ................................................................6
Schedule 2 ................................................................8
RECOMMENDED FLUIDS AND LUBRI-
CANTS ................................................................
10
Fluids and Lubricants ..............................................10
SAE Viscosity Number ............................................10
ENGINE MAINTENANCE ...................................12
Checking Drive Belts ...............................................12
Changing Engine Coolant .......................................12
Checking Fuel Line .................................................15
Changing Fuel Filter ................................................15
Changing Engine Air Cleaner Filter .........................15
Changing Engine Oil ................................................16
Changing Oil Filter ...................................................16
Changing Spark Plugs .............................................18
Checking EVAP Vapor Line .....................................19
CHASSIS AND BODY MAINTENANCE ...........20
Changing In-cabin Microfilter ...................................20
Checking Exhaust System .......................................21
Checking Automatic Transmission Fluid (ATF) .......21
Changing Automatic Transmission Fluid (ATF) .......23
Changing Transfer Fluid ..........................................23
Checking Transfer Fluid ..........................................24
Checking Propeller Shaft .........................................24
Checking Final Drive Oil ..........................................24
Changing Final Drive Oil ..........................................25
Balancing Wheels ....................................................25
Tire Rotation ............................................................27
Checking Brake Fluid Level and Leaks ...................27
CheckingBrake Line and Cables .............................27
Checking Disc Brake ...............................................27
Checking Steering Gear and Linkage ......................28
Checking Power Steering Fluid and Line ................28
Checking Axle and Suspension Parts .....................29
Lubricating Locks, Hinges and Hood Latches .........30
Checking Seat Belts, Buckles, Retractors, An-
chors and Adjusters .................................................
30

MA-6
< SERVICE INFORMATION >
PERIODIC MAINTENANCE
PERIODIC MAINTENANCE
Introduction of Periodic MaintenanceINFOID:0000000003533860
Two different maintenance schedules are provided, and should be used, depending upon the conditions in
which the vehicle is mainly operated. After 60,000 miles (96,000 km) or 48 months, continue the periodic
maintenance at the same mileage or time intervals, whichever comes first.
Maintenance for Off-road Driving (4WD only)INFOID:0000000003533861
After driving the vehicle off-road through sand, mud, or water; more frequent maintenance may be required for
the following items:
Brake pads and rotors
Brake lines and hoses
Rear final drive oil, transmission fluid, and transfer fluid
Steering linkage
Drive shafts
Engine air cleaner filter
In-cabin microfilters
Schedule 1INFOID:0000000003533862
EMISSION CONTROL SYSTEM MAINTENANCE
Abbreviations: R = Replace. I = Inspect. Correct or replace if necessary. [ ]: At the mileage intervals only
Schedule 1Follow Periodic Maintenance Schedule 1 if your driving habits frequently includes
one or more of the following driving conditions:
• Repeated short trips of less than 5 miles (8 km).
• Repeated short trips of less than 10 miles (16 km) with outside temperatures re-
maining below freezing.
• Operating in hot weather in stop-and-go “rush hour” traffic.
• Extensive idling and/or low speed driving for long distances, such as police, taxi
or door-to-door delivery use.
• Driving in dusty conditions.
• Driving on rough, muddy, or salt spread roads.
• Towing a trailer or using a car-top carrier.Emission Control Sys-
tem MaintenanceMA-6
Chassis and Body
MaintenanceMA-6
Schedule 2Follow Periodic Maintenance Schedule 2 if none of the driving conditions shown
in Schedule 1 apply to the driving habits.Emission Control Sys-
tem MaintenanceMA-8Chassis and Body
MaintenanceMA-8
MAINTENANCE OPERATIONMAINTENANCE INTERVAL
Reference
Section -
Page or -
Content Title Perform at number of miles, kilo-
meters or months, whichever
comes first.Miles x 1,000
(km x 1,000)
Months3.75
(6)
37.50
(12)
611 . 2 5
(18)
915
(24)
1218.75
(30)
1522.5
(36)
1826.25
(42)
2130
(48)
24
Drive belts NOTE (1)MA-12
Air cleaner filter NOTE (2) [R]MA-15
EVAP vapor linesI*MA-19
Fuel linesI*MA-15
Fuel filter NOTE (3)—
Engine coolant NOTE (4)MA-12
Engine oil R R R R R R R RMA-16
Engine oil filter R R R R R R R RMA-16
Spark plugs (double PLATINUM-
TIPPED type)Replace every 105,000 miles (169,000 km).EM-29
Intake and exhaust valve clear-
ance*NOTE (5)EM-103