ENGINE CONTROL SYSTEM SYMPTOMSEC-481
< SYMPTOM DIAGNOSIS > [VK56DE]
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SYMPTOM DIAGNOSIS
ENGINE CONTROL SYSTEM SYMPTOMS
Symptom Matrix ChartINFOID:0000000001351340
SYSTEM — BASIC ENGINE CONTROL SYSTEM
SYMPTOM
Refer-
ence page
HARD/NO START/RESTART (EXCP. HA)
ENGINE STALL
HESITATION/SURGING/FLAT SPOT
SPARK KNOCK/DETONATION
LACK OF POWER/POOR ACCELERATION
HIGH IDLE/LOW IDLE
ROUGH IDLE/HUNTING
IDLING VIBRATION
SLOW/NO RETURN TO IDLE
OVERHEATS/WATER TEMPERATURE HIGH
EXCESSIVE FUEL CONSUMPTION
EXCESSIVE OIL CONSUMPTION
BATTERY DEAD (UNDER CHARGE)
Warranty symptom code AA AB AC AD AE AF AG AH AJ AK AL AM HA
Fuel Fuel pump circuit 11232 22 3 2EC-402
Fuel pressure regulator system 334444444 4 EC-494
Injector circuit11232 22 2EC-399
Evaporative emission system 334444444 4 EC-37
Air Positive crankcase ventilation sys-
tem 334444444 41
EC-421
Incorrect idle speed adjustment 1 1 1 1 1EC-13
Electric throttle control actuator 112332222 2 2 EC-359
,
EC-362
,
EC-366
,
EC-368
IgnitionIncorrect ignition timing adjustment 33111 11 1EC-13
Ignition circuit 11222 22 2EC-411
Main power supply and ground circuit 22333 33 23 EC-83
Revision: March 20102008 QX56
EC-482
< SYMPTOM DIAGNOSIS >[VK56DE]
ENGINE CONTROL SYSTEM SYMPTOMS
1 - 6: The numbers refer to the order of inspection.
(continued on next page)
SYSTEM — ENGINE MECHANICAL & OTHER
Mass air flow sensor circuit
1
12 2
222 2 EC-106,
EC-113
Engine coolant temperature sensor circuit
333
EC-124,
EC-132
Air fuel ratio (A/F ) sensor 1 circuit EC-141
,
EC-145
,
EC-149
,
EC-153
,
EC-385
Throttle position sensor circuit
22EC-128
,
EC-194
,
EC-310
,
EC-312
,
EC-377
Accelerator pedal position sensor circuit 3 2 1EC-289
,
EC-370
,
EC-373
,
EC-381
Knock sensor circuit 23EC-204
Crankshaft position sensor (POS) circuit 2 2 EC-207
Camshaft position sensor (PHASE) circuit 3 2 EC-211
Vehicle speed signal circuit2 3 33EC-280
Power steering pressu re sensor circuit 23 3 EC-286
ECM 22333333333 EC-289,
EC-291
Intake valve timing control solenoid valve cir-
cuit 32 13223 3
EC-103
Park/Neutral position (PNP) signal circuit3 3 3 33EC-296
Refrigerant pressure sensor circuit 233 4 EC-423
Electrical load signal circuit 3EC-397
Air conditioner circuit 223333333 3 2 HAC-24
ABS actuator and electric unit (control unit) 4 BRC-37
SYMPTOM
Refer-
ence page
HARD/NO START/RESTART (EXCP. HA)
ENGINE STALL
HESITATION/SURGING/FLAT SPOT
SPARK KNOCK/DETONATION
LACK OF POWER/POOR ACCELERATION
HIGH IDLE/LOW IDLE
ROUGH IDLE/HUNTING
IDLING VIBRATION
SLOW/NO RETURN TO IDLE
OVERHEATS/WATER TEMPERATURE HIGH
EXCESSIVE FUEL CONSUMPTION
EXCESSIVE OIL CONSUMPTION
BATTERY DEAD (UNDER CHARGE)
Warranty symptom code AA AB AC AD AE AF AG AH AJ AK AL AM HA
Revision: March 2010 2008 QX56
ENGINE CONTROL SYSTEM SYMPTOMSEC-483
< SYMPTOM DIAGNOSIS > [VK56DE]
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SYMPTOM
Reference
page
HARD/NO START/RESTART (EXCP. HA)
ENGINE STALL
HESITATION/SURGING/FLAT SPOT
SPARK KNOCK/DETONATION
LACK OF POWER/POOR ACCELERATION
HIGH IDLE/LOW IDLE
ROUGH IDLE/HUNTING
IDLING VIBRATION
SLOW/NO RETURN TO IDLE
OVERHEATS/WATER TEMPERATURE HIGH
EXCESSIVE FUEL CONSUMPTION
EXCESSIVE OIL CONSUMPTION
BATTERY DEAD (UNDER CHARGE)
Warranty symptom code AA AB AC AD AE AF AG AH AJ AK AL AM HA
Fuel Fuel tank 5
5 FL-11
Fuel piping
5 5 5 5 55FL-6
Va p o r l o c k —
Valve deposit 5 555 55 5—
Poor fuel (Heavy weight gasoline,
Low octane) —
Air Air duct
55555 5 EM-25
Air cleaner
EM-25
Air leakage from air duct
(Mass air flow sensor — electric
throttle control actuator)
5555 EM-25
Electric throttle control actuator
EM-26
Air leakage from intake manifold/
Collector/GasketEM-26
Cranking Battery
111111
11
PG-73
Generator circuit
CHG-8
Starter circuit3 STR-8
Signal plate6 EM-45
Park/Neutral position (PNP) sig-
nal4
TM-43
Engine Cylinder head
55555 55 5 EM-68
Cylinder head gasket 4 3
Cylinder block
66666 66 64
EM-82
Piston
Piston ring
Connecting rod
Bearing
Crankshaft
Va l v e
mecha-
nism Timing chain
55555 55 5EM-45
Camshaft
EM-53
Intake valve timing controlEM-53
Intake valve
3EM-68
Exhaust valve
Revision: March 2010 2008 QX56
EC-484
< SYMPTOM DIAGNOSIS >[VK56DE]
ENGINE CONTROL SYSTEM SYMPTOMS
1 - 6: The numbers refer to the order of inspection.Exhaust Exhaust manifold/Tube/Muffler/
Gasket 55555 55 5EM-30
,
EX-
5Three way catalyst
Lubrica-
tion Oil pan/Oil strainer/Oil pump/Oil
filter/Oil gallery/Oil cooler
55555 55 5EM-33
,
LU-
14 , LU-11 ,
LU-12
Oil level (Low)/Filthy oil LU-8, "In-
spection"
Cooling Radiator/Hose/Radiator filler cap
55555 55 45 CO-15
Thermostat
5CO-22
Water pump CO-20
Water galleryCO-6
Cooling fan5CO-18,
CO-
19
Coolant level (Low)/Contaminat-
ed coolant 5
CO-10
IVIS (INFINITI Vehicle Immobilizer System —
NATS) 11
SEC-8
SYMPTOM
Reference
page
HARD/NO START/RESTART (EXCP. HA)
ENGINE STALL
HESITATION/SURGING/FLAT SPOT
SPARK KNOCK/DETONATION
LACK OF POWER/POOR ACCELERATION
HIGH IDLE/LOW IDLE
ROUGH IDLE/HUNTING
IDLING VIBRATION
SLOW/NO RETURN TO IDLE
OVERHEATS/WATER TEMPERATURE HIGH
EXCESSIVE FUEL CONSUMPTION
EXCESSIVE OIL CONSUMPTION
BATTERY DEAD (UNDER CHARGE)
Warranty symptom code AA AB AC AD AE AF AG AH AJ AK AL AM HA
Revision: March 2010 2008 QX56
EM-68
< ON-VEHICLE REPAIR >
CYLINDER HEAD
CYLINDER HEAD
Exploded ViewINFOID:0000000006055158
Removal and InstallationINFOID:0000000006055159
REMOVAL
1. Remove the engine assembly from the vehicle. Refer to EM-78, "Removal and Installation".
2. Remove the following components and related parts: • Drive belt auto tensioner and idler pulley. Refer to EM-14, "
Drive Belt Auto Tensioner and Idler Pulley".
• Generator assembly and bracket. Refer to CHG-22, "
Removal and Installation".
• Fuel tube and fuel injector assembly. Refer to EM-40, "
Removal and Installation".
• Intake manifold. Refer to EM-26, "
Removal and Installation".
• Thermostat housing and hose. Refer to CO-22, "
Removal and Installation".
• Rocker cover. Refer to EM-38, "
Removal and Installation".
• Oil pan and oil strainer. Refer to EM-33, "
Removal and Installation".
3. Remove the crankshaft pulley, front cover, oil pump, and timing chain. Refer to EM-45, "
Removal and
Installation".
4. Remove the camshaft sprockets and camshafts. Refer to EM-53, "
Removal and Installation".
5. Remove the cylinder head bolts in reverse of order shown.
6. Remove the cylinder heads.
INSPECTION AFTER REMOVAL
Cylinder Head Bolts Diameter
1. Harness bracket 2. Engine coolant temperature sensor 3. Washer
4. Cylinder head gasket (LH) 5. Cylinder head (RH) 6. Cylinder head bolt
7. Cylinder head gasket (RH) 8. Cylinder head (LH)
KBIA2528E
PBIC0068E
Revision: March 2010 2008 QX56
SERVICE INFORMATION FOR ELECTRICAL INCIDENTGI-35
< BASIC INSPECTION >
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• Do not apply excessive shock to the control unit by dropping or hit- ting it.
• Be careful to prevent condensation in the control unit due to rapid
temperature changes and do not let water or rain get on it. If water
is found in the control unit, dry it fully and then install it in the vehi-
cle.
• Be careful not to let oil to get on the control unit connector.
• Avoid cleaning the control unit with volatile oil.
• Do not disassemble the control unit, and do not remove the upper and lower covers.
• When using a DMM, be careful not to let test probes get close to each other to prevent the power transistor in the control unit from
damaging battery voltage because of short circuiting.
• When checking input and output signals of the control unit, use the specified check adapter.
How to Check TerminalINFOID:0000000001539225
CONNECTOR AND TERMINAL PIN KIT
• Use the connector and terminal pin kits listed below when replacing connectors or terminals.
• The connector and terminal pin kits contain some of the most commonly used NISSAN/INFINITI connectors
and terminals. For detailed connector and terminal pin r eplacement procedures, refer to the latest NISSAN/
INFINITI CONNECTOR AND TERMINAL PIN SERVICE MANUAL.
SAIA0255E
SEF348N
Revision: March 2010 2008 QX56
PRECAUTIONSHA-9
< PRECAUTION >
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*: Always check with the Parts Department for the latest parts information.
WARNING:
Make sure all refrigerant is discharged into the recycling equipment and the pressure in the system is
less than atmospheric pressure. Then gradually loo sen the discharge side hose fitting and remove it.
CAUTION:
When replacing or cleaning refrigerant cycle components, observe the following.
• When the compressor is removed, store it in the same position as it is when mounted on the car.
Failure to do so will cause oil to enter the low pressure chamber.
• When connecting tubes, always use a to rque wrench and a back-up wrench.
• After disconnecting tubes, immediately plug all op enings to prevent entry of dirt and moisture.
• When installing an air conditione r in the vehicle, connect the pipes as the final stage of the opera-
tion. Do not remove the seal caps of pipes and other components until just before required for con-
nection.
• Allow components stored in cool areas to warm to working area temperature before removing seal
caps. This prevents condensation from forming inside A/C components.
• Thoroughly remove moisture from the refrigeration system before charging the refrigerant.
• Always replace used O-rings.
• When connecting tube, apply oil to circle of the O-ri ngs shown in illustration. Be careful not to apply
oil to threaded portion.
Oil name: NISSAN A/C System Oil Type S or equivalent
• O-ring must be closely attached to dented portion of tube.
• When replacing the O-ring, be careful not to damage O-ring and tube.
• Connect tube until you hear it cl ick, then tighten the nut or bolt by hand until snug. Make sure that
the O-ring is installed to tube correctly.
• After connecting line, conduct leak test and make sure that there is no leakage from connections.
When the gas leaking point is f ound, disconnect that line and replace the O-ri ng. Then tighten con-
nections of seal seat to the specified torque.
Connec-
tion type O-ring
size Part number* D mm (in) W mm (in)
New 8 92471 N8210 6.8 (0.268) 1.85 (0.0728)
Former 10 J2476 89956 9.25 (0.3642) 1.78 (0.0701) New 1292472 N8210 10.9 (0.429) 2.43 (0.0957)
Former 92475 71L00 11.0 (0.433) 2.4 (0.094)
New 1692473 N8210 13.6 (0.535) 2.43 (0.0957)
Former 92475 72L00 14.3 (0.563) 2.3 (0.091)
New 1992474 N8210 16.5 (0.650) 2.43 (0.0957)
Former 92477 N8200 17.12 (0.6740) 1.78 (0.0701)
New 24 92195 AH300 21.8 (0.858) 2.4 (0.094)
SHA814E
Revision: March 2010 2008 QX56
HA-22
< ON-VEHICLE MAINTENANCE >
OIL
OIL
Maintenance of Oil Quantity in CompressorINFOID:0000000001516645
The oil in the compressor circulates through the system with the refrigerant. Add oil to compressor when
replacing any component or after a large refrigerant leakage has occurred. It is important to maintain the spec-
ified amount.
If oil quantity is not maintained properly, the following malfunctions may result:
• Lack of oil: May lead to a seized compressor
• Excessive oil: Inadequate cooling (thermal exchange interference)
OIL
Name: NISSAN A/C System Oil Type S or equivalent
CHECKING AND ADJUSTING
CAUTION:
If excessive oil leakage is noted, do not perform the oil return operation.
Start the engine and set the following conditions:
Test Condition
• Engine speed: Idling to 1,200 rpm
• A/C switch: On
• Blower fan speed: MAX position
• Temp. control: Optional [Set so that intake air temperature is 25 ° to 30 ° C (77 ° to 86 °F)]
• Intake position: Recirculation ( )
• Perform oil return operation for about ten minutes
Adjust the oil quantity according to the following table.
Oil Adjusting Procedure for Components Replacement Except Compressor
After replacing any of the following major components, add the correct amount of oil to the system.
Amount of Oil to be Added
• *1: If refrigerant leak is small, no addition of oil is needed.
Oil Adjustment Procedure for Compressor Replacement
Part replaced Oil to be added to system
Remarks
Amount of oil
m (US fl oz, Imp fl oz)
Front evaporator 75 (2.5, 2.6)—
Rear evaporator 75 (2.5, 2.6)—
Condenser 75 (2.5, 2.6)—
Liquid tank 5 (0.2, 0.2)Add if compressor is not replaced.
In case of refrigerant leak 30 (1.0, 1.1)
Large leak
— Small leak *1
Revision: March 2010 2008 QX56