2008 INFINITI QX56 spark plugs replace

EC-8
< BASIC INSPECTION >[VK56DE]
DIAGNOSIS AND REPAIR WORKFLOW
BASIC INSPECTION
DIAGNOSIS AND REPAIR WORKFLOW
Trouble Diagnosis IntroductionINFOID:0000000001351337
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-III (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 Di agnostic Worksheet like the example
on "Worksheet Sample" should be used.
Start your diagnosis by looking fo r conventional malfunctions first.
This will help troubleshoot driveability malfunctions on an electroni-
cally controlled engine vehicle.
WORK FLOW
MEF036D
SEF233G
SEF234G
Revision: March 2010 2008 QX56

P0172, P0175 FUEL INJECTION SYSTEM FUNCTION
EC-185
< COMPONENT DIAGNOSIS > [VK56DE]
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Hold the accelerator pedal as steady as possible.
The similar conditions to (1st trip) Freeze Frame Da
ta 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-185, "
Diagnosis Procedure". If engine does not start, remove spark plugs and
check for fouling, etc.
Diagnosis ProcedureINFOID:0000000001351520
1.CHECK EXHAUST GAS LEAK
1. Start engine and run it at idle.
2. Listen for an exhaust gas leak before three way catalyst (manifold).
OK or NG
OK >> GO TO 2.
NG >> Repair or replace.
2.CHECK FOR INTAKE AIR LEAK
Listen for an intake air leak after the mass air flow sensor.
OK or NG
OK >> GO TO 3.
NG >> Repair or replace.
3.CHECK A/F SENSOR 1 IN PUT SIGNAL CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect corresponding A/F sensor 1 harness connector.
3. Disconnect ECM harness connector.
4. Check harness continuity between the following terminals. Refer to Wiring Diagram.
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)
condition When 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).
PBIB1216E
BBIA0376E
Revision: March 2010 2008 QX56

P0300, P0301, P0302, P0303, P0304, P0305, P0306, P0307, P0308 MISFIRE
EC-201
< COMPONENT DIAGNOSIS > [VK56DE]
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• Do not approach to the spark pl
ug and the ignition coil within 50cm. Be careful not to get an
electrical shock while checking , because the electrical dischar ge 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-411, "
Diagnosis Procedure" .
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-16, "
Removal
and Installation".
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-
16, "Removal and Installation".
9.CHECK COMPRESSION PRESSURE
Check compression pressure. Refer to EM-23, "
Checking Compression Pressure".
OK or NG
OK >> GO TO 10.
NG >> Check pistons, piston rings, valves, valve seats and cylinder head gaskets.
10.CHECK FUEL PRESSURE
1. Install all removed parts.
2. Release fuel pressure to zero. Refer to EC-494, "
Fuel Pressure Check".
3. Install fuel pressure gauge and check fuel pressure. Refer to EC-494, "
Fuel Pressure Check".
Spark should be generated.
SEF156I
Spark should be generated.
At idling: Approximately 350 kPa (3.57 kg/cm
2 , 51 psi)
Revision: March 2010
2008 QX56

EC-218
< COMPONENT DIAGNOSIS >[VK56DE]
P0420, P0430 THREE WAY CATALYST FUNCTION
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-411, "
Diagnosis Procedure".
8.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-16, "
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-
16, "Removal and Installation".
10.CHECK FUEL INJECTOR
1. Turn ignition switch OFF.
2. Remove fuel injector assembly. Refer to EM-40, "
Removal and Installation".
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 GI-35, "
How to Check Terminal" and GI-38, "Intermittent Incident".
Trouble is fixed.>> INSPECTION END
Trouble is not fixed.>>Replace three way catalyst assembly. Spark should be generated.
SEF156I
Spark should be generated.
Revision: March 2010
2008 QX56

MA-8
< ON-VEHICLE MAINTENANCE >
PERIODIC MAINTENANCE
PERIODIC MAINTENANCE
Introduction of Periodic MaintenanceINFOID:0000000001606164
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 ti me intervals, whichever comes first.
Maintenance for Off-road Driving (4WD only)INFOID:0000000001606165
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:0000000001606166
EMISSION CONTROL SYSTEM MAINTENANCE
Abbreviations: R = Replace. I = Inspect. Correct or r eplace 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 Maintenance
MA-8
Chassis and Body
Maintenance
MA-8
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-10Chassis and Body
Maintenance
MA-10
MAINTENANCE OPERATION
MAINTENANCE 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) Months 3.75
(6)3 7.50
(12) 6 11 . 2 5
(18) 9 15
(24) 12 18.75
(30)15 22.5
(36) 18 26.25
(42)21 30
(48) 24
Drive belts NOTE (1) MA-14
Air cleaner filterNOTE (2) [R]MA-17
EVAP vapor lines I*MA-21
Fuel lines I*MA-17
Fuel filter NOTE (3) —
Engine coolant NOTE (4) MA-14
Engine oilR R R R R R R R MA-18
Engine oil filterR R R R R R R R MA-18
Spark plugs (double PLATINUM-
TIPPED type)Replace every 105,000 miles (169,000 km).
MA-20
Intake and exhaust valve clear-
ance*NOTE (5)
EM-108
Revision: March 2010 2008 QX56

PERIODIC MAINTENANCEMA-9
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(1) After 60,000 miles (96,000 km) or 48 months, inspect every 15,000 miles (24,000 km) or 12 months. Replace drive belts if da
maged.
(2) If operating mainly in dusty conditions, more frequent maintenance may be required.
(3) Maintenance-free item. For service procedures, go to the FL section.
(4) After 60,000 miles (96,000 km) or 48 months, replace every 30,000 miles (48,000 km) or 24 months.
(5) If valve noise increases, inspect valve clearance.
* Maintenance items and inte rvals with “*” are recommended by NISSAN for reliable vehicle operation. The owner need not perform
such maintenance in order to maintain the emission warranty or manufacturer recall liability. Other maintenance items and inter vals are
required.
CHASSIS AND BODY MAINTENANCE
Abbreviations: R = Replace. I = Inspect. Correct or replace if necessary. L = Lubricate. [ ]: At the mileage intervals only.
MAINTENANCE OPERATION MAINTENANCE 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) Months 33.75
(54)27 37.5
(60) 30 41.25
(66)33 45
(72) 36 48.75
(78)39 52.5
(84) 42 56.25
(90)45 60
(96) 48
Drive belts NOTE (1) I*MA-14
Air cleaner filter NOTE (2) [R]MA-17
EVAP vapor lines I*MA-21
Fuel lines I*MA-17
Fuel filter NOTE (3) —
Engine coolant NOTE (4) R*MA-14
Engine oil R R R R R R R R MA-18
Engine oil filterR R R R R R R R MA-18
Spark plugs (double PLATINUM-
TIPPED type)Replace every 105,000 miles (169,000 km).
MA-20
Intake and exhaust valve clear-
ance*NOTE (5)
EM-108
MAINTENANCE OPERATIONMAINTENANCE INTERVAL
Reference
Section- Page
or
- Content Title
Perform at number of miles, kilometers or
months, whichever comes first. Miles x
1,000(km x
1,000)
Months 3.75
(6)3 7.5
(12) 6 11 . 2 5
(18) 9 15
(24) 12 18.75
(30)15 22.5
(36) 18 26.25
(42)21 30
(48) 24
Brake lines and cables IIMA-30
Brake pads and rotors II I IMA-30
Automatic transmission fluid NOTE (1)IIMA-23
Transfer fluid and front final drive oil NOTE (1)IIMA-26,
MA-26
Rear final drive oil NOTE (1)IIMA-26
Steering gear and linkage, axle and suspension
parts II I I
MA-30,
MA-31
Tire Rotation NOTE (2) MA-29
Drive shaft boots and propeller shaft (4WD)II I IMA-26
Exhaust system II I IMA-23
In-cabin microfilter RRMA-22
Revision: March 2010 2008 QX56

MA-10
< ON-VEHICLE MAINTENANCE >
PERIODIC MAINTENANCE
(1) If towing a trailer, or using a car-top carrier, or driving on rough or muddy roads, change (not just inspect) oil at every 30,000 miles
(48,000 km) or 24 months.
(2) Refer to “Tire rotation” unde r the “General maintenance” heading earlier in this section.
Schedule 2INFOID:0000000001606167
EMISSION CONTROL SYSTEM MAINTENANCE
Abbreviations: R = Replace. I = Inspect. Correct or r eplace if necessary. [ ]: At the mileage intervals only
(1) After 60,000 miles (96,000 km) or 48 months, inspect every 15,000 miles (24,000 km) or 12 months. Replace drive belts if damaged.
(2) Maintenance-free item. For service procedures, go to FL section.
(3) After 60,000 miles (96,000 km) or 48 months, replace every 30,000 miles (48,000 km) or 24 months.
(4) If valve noise increases, inspect valve clearance.
* Maintenance items and intervals with “*” are recommended by NISSAN for reliable vehicle operation. The owner need not perform
such maintenance in order to maintain the emission warranty or manufacturer recall liability. Other maintenance items and inter vals are
required.
CHASSIS AND BODY MAINTENANCE
MAINTENANCE OPERATION MAINTENANCE INTERVAL
Reference
Section
- Page or
- Content
Title
Perform at number of miles, kilometers or
months, whichever comes first. Miles x
1,000(km x
1,000)
Months 33.75
(54)
27 37.5
(60)
30 41.25
(66)
33 45
(72)
36 48.75
(78)
39 52.5
(84)
42 56.25
(90)
45 60
(96)
48
Brake lines and cables IIMA-30
Brake pads and rotors IIIIMA-30
Automatic transmission fluid NOTE (1)IIMA-23
Transfer fluid and front final drive oil NOTE (1)IIMA-26,
MA-26
Rear final drive oil NOTE (1)IIMA-26
Steering gear and linkage, axle and suspen-
sion parts IIIIMA-30,
MA-31
Tire Rotation NOTE (2) MA-29
Drive shaft boots and propeller shaft (4WD)IIIIMA-26
Exhaust system IIIIMA-23
In-cabin microfilter RRMA-22
MAINTENANCE OPERATION MAINTENANCE INTERVAL
Reference
Section - Page
or - Content Ti- tle
Perform at number of miles, kilometers
or months, whichever comes first. Miles x 1,000
(km x 1,000)
Months 7.5
(12)
6 15
(24)
12 22.5
(36)
18 30
(48)
24 37.5
(60)
30 45
(72)
36 52.5
(84)
42 60
(96)
48
Drive belts NOTE (1) I*MA-14
Air cleaner filter [R][R]MA-17
EVAP vapor lines I*I*MA-21
Fuel lines I*I*MA-17
Fuel filter NOTE (2) —
Engine coolant NOTE (3) R*MA-14
Engine oil R R R R R R R R MA-18
Engine oil filterR R R R R R R R MA-18
Spark plugs (PLATINUM-TIPPED
type) Replace every 105,000 miles (169,000 km).
MA-20
Intake and exhaust valve clearance* NOTE (4) EM-108
Revision: March 20102008 QX56