EC-476
< 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-103,
EC-109
Engine coolant temperature sensor circuit
333
EC-120,
EC-128
Air fuel ratio (A/F ) sensor 1 circuit EC-136
,
EC-140
,
EC-143
,
EC-146
,
EC-377
Throttle position sensor circuit 22EC-124
,
EC-185
,
EC-302
,
EC-304
,
EC-369
Accelerator pedal position sensor circuit 3 2 1 EC-280
,
EC-362
,
EC-365
,
EC-373
Knock sensor circuit 2 3 EC-195
Crankshaft position sensor (POS) circuit 2 2EC-198
Camshaft position sensor (PHASE) circuit 3 2 EC-202
Vehicle speed signal circuit 2 3 3 3 EC-271
Power steering pressure sensor circuit 2 3 3 EC-277
ECM 22333333333 EC-280,
EC-282
Intake valve timing control solenoid valve cir-
cuit 32 13223 3
EC-100
Transmission range signal circuit 3 3 3 3 3 EC-288
Refrigerant pressure sensor circuit 2 3 3 4EC-416
Electrical load signal circuit 3EC-390
Air conditioner circuit 223333333 3 2HAC-25
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: December 20092009 QX56
ENGINE CONTROL SYSTEM SYMPTOMSEC-477
< 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 5 5
FL-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-77
Generator circuit
CHG-6
Starter circuit 3STR-8
Signal plate 6EM-45
Transmission range signal 4TM-44
Engine Cylinder head
55555 55 5 EM-68
Cylinder head gasket 4 3
Cylinder block
66666 66 6 4
EM-83
Piston
Piston ring
Connecting rod
Bearing
Crankshaft
Va l v e
mecha-
nism Timing chain
55555 55 5 EM-45
Camshaft
EM-53
Intake valve timing controlEM-53
Intake valve
3EM-68
Exhaust valve
Revision: December 20092009 QX56
EC-478
< 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 5 EM-30
,
EX-
5Three way catalyst
Lubrica-
tion Oil pan/Oil strainer/Oil pump/Oil
filter/Oil gallery/Oil cooler
55555 55 5 EM-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 5
CO-22
Water pumpCO-20
Water galleryCO-6
Cooling fan 5CO-18,
CO-
19
Coolant level (Low)/Contaminat-
ed coolant 5
CO-10
IVIS (INFINITI Vehicle Immobilizer System —
NATS) 11
SEC-6
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: December 20092009 QX56
PRECAUTIONSEC-481
< PRECAUTION > [VK56DE]
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PrecautionINFOID:0000000003771743
Always use a 12 volt battery as power source.
Do not attempt to disconnect battery cables while engine is
running.
Before connecting or disc onnecting the ECM harness con-
nector, turn ignition switch OFF and disconnect negative bat-
tery cable. Failure to do so may damage the ECM because
battery voltage is applied to ECM even if ignition switch is
turned OFF.
Before removing parts, turn ig nition switch OFF and then dis-
connect negative battery cable.
Do not disassemble ECM.
If a battery cable is disconnect ed, the memory will return to
the ECM value.
The ECM will now start to sel f-control at its initial value.
Engine operation can vary slight ly when the terminal is dis-
connected. However, this is no t an indication of a malfunc-
tion. Do not replace parts b ecause of a slight variation.
If the battery is disconnected, the following emission-related
diagnostic information will be lost within 24 hours.
- Diagnostic trouble codes
- 1st trip diagnostic trouble codes
- Freeze frame data
- 1st trip freeze frame data
- System readiness test (SRT) codes
- Test values
When connecting ECM harness c onnector, fasten it securely
with a lever as far as it will go as shown in the figure.
When connecting or disconnect ing pin connectors into or
from ECM, take care not to damage pin terminals (bend or
break).
Make sure that there are not any bends or breaks on ECM pin
terminal, when conn ecting pin connectors.
Securely connect ECM harness connectors.
A poor connection can cause an extremely high (surge) volt-
age to develop in coil and cond enser, thus resulting in dam-
age to ICs.
Keep engine control system harness at least 10 cm (4 in) away
from adjacent harness, to prevent engine control system mal-
functions due to receiving externa l noise, degraded operation
of ICs, etc.
Keep engine control system parts and harness dry.
SEF289H
PBIB1164E
BBIA0387E
PBIB0090E
Revision: December 20092009 QX56
EC-492
< ON-VEHICLE REPAIR >[VK56DE]
INTAKE VALVE TIMING CONTROL
INTAKE VALVE TIMING CONTROL
Intake Valve Timing Control Solenoid Valve (LH)INFOID:0000000003771750
REMOVAL
1. Remove engine room cover using power tool. Refer to
EM-24, "Removal and Installation".
2. Remove air duct and resonator assembly. Refer to EM-25, "Removal and Installation"
.
3. Remove drive belt. Refer to EM-13, "Removal and Installation"
.
4. Disconnect Intake valve timing controlintake valve timing control solenoid valve connector (LH).
5. Remove Intake valve timing control solenoid valve (LH) (2) from Intake valve timing control solenoid valve cover (LH) (1).
INSTALLATION
Installation is in the reverse order of removal.
CAUTION:
Replace the O-ring (3) of the Int ake valve timing control solenoid valve with a new one, then lubricate
O-ring with engine oil before installing.
Intake Valve Timing Control Solenoid Valve (RH)INFOID:0000000003771751
REMOVAL
1. Remove drive belt. Refer to EM-13, "Removal and Installation".
2. Disconnect Intake valve timing control solenoid valve connector (RH).
3. Remove Intake valve timing control solenoid valve (RH) (3) from Intake valve timing control solenoid valve cover (RH) (1).
INSTALLATION
Installation is in the reverse order of removal.
CAUTION:
Replace the O-ring (2) of the Int ake valve timing control solenoid valve with a new one, then lubricate
O-ring with engine oil before installing.
AWBIA0145ZZ
Intake valve timing control sole-
noid valve bolt : 9.6 N·m (0.98 kg-m, 85 in-lb)
AWBIA0144ZZ
Intake valve timing control sole-
noid valve bolt: 9.6 N·m (0.98 kg-m, 85 in-lb)
Revision: December 20092009 QX56
INTAKE VALVE TIMING CONTROLEC-493
< ON-VEHICLE REPAIR > [VK56DE]
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Intake Valve Timing Control Position Sensor (LH)INFOID:0000000003771752
REMOVAL
1. Remove engine room cover using power tool. Refer to
EM-24, "Removal and Installation".
2. Remove air duct and resonator assembly. Refer to EM-25, "Removal and Installation"
.
3. Disconnect intake valve timing control position sensor connector (LH).
4. Remove intake valve timing control position sensor (LH) (1) from Intake valve timing control solenoid valve cover (LH) (3).
INSTALLATION
Installation is in the reverse order of removal.
CAUTION:
Replace the O-ring (2) of the intake valve timing control position sensor with a new one, then lubricate
O-ring with engine oil before installing.
Intake Valve Timing Cont rol Position Sensor (RH)INFOID:0000000003771753
REMOVAL
1. Remove engine room cover using power tool. Refer to EM-24, "Removal and Installation".
2. Disconnect intake valve timing control position sensor connector (RH).
3. Remove intake valve timing control position sensor (RH) (1) from Intake valve timing control solenoid valve cover (RH) (3).
INSTALLATION
Installation is in the reverse order of removal.
CAUTION:
Replace the O-ring (2) of the intake valve timing control position sensor with a new one, then lubricate
O-ring with engine oil before installing.
Camshaft Position Sensor (PHASE)INFOID:0000000003771754
REMOVAL
1. Remove engine room cover using power tool. Refer to EM-24, "Removal and Installation".
2. Remove air duct and resonator assembly. Refer to EM-25, "Removal and Installation"
.
3. Disconnect camshaft position sensor connector.
AWBIA0141ZZ
Intake valve timing control position senso r bolt : 9.6 N·m (0.98 kg-m, 85 in-lb)
AWBIA0143ZZ
Intake valve timing control position sensor bolt : 9.6 N·m (0.98 kg-m, 85 in-lb)
Revision: December 20092009 QX56
EC-494
< ON-VEHICLE REPAIR >[VK56DE]
INTAKE VALVE TIMING CONTROL
4. Remove camshaft position sensor (2) from Intake valve timing
control solenoid valve cover (LH) (1).
INSTALLATION
Installation is in the reverse order of removal.
CAUTION:
Replace the O-ring (3) of the cam shaft position sensor with a new on e, then lubricate O-ring with
engine oil before installing.
AWBIA0142ZZ
Camshaft position sensor bolt : 9.6 N·m (0.98 kg-m, 85 in-lb)
Revision: December 20092009 QX56
EM-1
ENGINE
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SECTION EM
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CONTENTS
ENGINE MECHANICAL
PRECAUTION ....... ........................................3
PRECAUTIONS .............................................. .....3
Precaution for Supplemental Restraint System
(SRS) "AIR BAG" and "SEAT BELT PRE-TEN-
SIONER" ............................................................. ......
3
Precaution Necessary for Steering Wheel Rota-
tion After Battery Disconnect ............................... ......
3
Precaution for Drain Engine Coolant .........................4
Precaution for Disconnecting Fuel Piping .................4
Precaution for Removal and Disassembly ................4
Precaution for Inspection, Repair and Replace-
ment .................................................................... ......
4
Precaution for Assembly and Installation ..................4
Parts Requiring Angular Tightening ..........................4
Precaution for Liquid Gasket ............................... ......5
PREPARATION ............................................6
PREPARATION .............................................. .....6
Special Service Tool ........................................... ......6
Commercial Service Tool ..........................................8
FUNCTION DIAGNOSIS ..............................10
NOISE, VIBRATION, AND HARSHNESS
(NVH) TROUBLESHOOTING ........................ ....
10
NVH Troubleshooting - Engine Noise ................. ....10
Use the Chart Below to Help You Find the Cause
of the Symptom .......................................................
11
ON-VEHICLE MAINTENANCE ....................13
DRIVE BELTS ................................................ ....13
Exploded View .................................................... ....13
Checking Drive Belts ...............................................13
Removal and Installation .........................................13
Drive Belt Auto Tensioner and Idler Pulley ......... ....14
AIR CLEANER FILTER ......................................15
Exploded View .................................................... ....15
Removal and Installation (Viscous paper type) .......15
SPARK PLUG ...................................................16
Exploded View ..................................................... ....16
Removal and Installation .........................................16
CAMSHAFT VALVE CLEARANCE ..................18
Valve Clearance ......................................................18
COMPRESSION PRESSURE ...........................23
Checking Compression Pressure ............................23
ON-VEHICLE REPAIR .................................24
ENGINE ROOM COVER ...................................24
Removal and Installation ..................................... ....24
AIR CLEANER AND AIR DUCT .......................25
Exploded View .........................................................25
Removal and Installation .........................................25
INTAKE MANIFOLD .........................................26
Exploded View .........................................................26
Removal and Installation .........................................26
EXHAUST MANIFOLD AND THREE WAY
CATALYST ........................................................
30
Exploded View .........................................................30
Removal and Installation .........................................30
OIL PAN AND OIL STRAINER .........................33
Exploded View .........................................................33
Removal and Installation .........................................33
IGNITION COIL .................................................37
Exploded View .........................................................37
Removal and Installation .........................................37
ROCKER COVER .............................................38
Exploded View .........................................................38
Removal and Installation .........................................38
FUEL INJECTOR AND FUEL TUBE ................40
Exploded View .........................................................40
Removal and Installation .........................................40
Revision: December 20092009 QX56