Page 1830 of 4210
![INFINITI QX56 2010 Factory Service Manual ENGINE CONTROL SYSTEM SYMPTOMSEC-477
< SYMPTOM DIAGNOSIS > [VK56DE]
C
D
E
F
G H
I
J
K L
M A
EC
NP
O
SYMPTOM DIAGNOSIS
ENGINE CONTROL SYSTEM SYMPTOMS
Symptom Matrix ChartINFOID:0000000005149500
SYSTEM INFINITI QX56 2010 Factory Service Manual ENGINE CONTROL SYSTEM SYMPTOMSEC-477
< SYMPTOM DIAGNOSIS > [VK56DE]
C
D
E
F
G H
I
J
K L
M A
EC
NP
O
SYMPTOM DIAGNOSIS
ENGINE CONTROL SYSTEM SYMPTOMS
Symptom Matrix ChartINFOID:0000000005149500
SYSTEM](/manual-img/42/57032/w960_57032-1829.png)
ENGINE CONTROL SYSTEM SYMPTOMSEC-477
< SYMPTOM DIAGNOSIS > [VK56DE]
C
D
E
F
G H
I
J
K L
M A
EC
NP
O
SYMPTOM DIAGNOSIS
ENGINE CONTROL SYSTEM SYMPTOMS
Symptom Matrix ChartINFOID:0000000005149500
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-399
Fuel pressure regulator system 334444444 4 EC-489
Injector circuit11232 22 2EC-396
Evaporative emission system 334444444 4 EC-37
Air Positive crankcase ventilation sys-
tem 334444444 41
EC-417
Incorrect idle speed adjustment 1 1 1 1 1EC-13
Electric throttle control actuator 112332222 2 2 EC-356
,
EC-359
,
EC-363
,
EC-365
IgnitionIncorrect ignition timing adjustment 33111 11 1EC-13
Ignition circuit 11222 22 2EC-407
Main power supply and ground circuit 22333 33 23 EC-82
Revision: April 20092010 QX56
Page 1831 of 4210
![INFINITI QX56 2010 Factory Service Manual EC-478
< 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 sen INFINITI QX56 2010 Factory Service Manual EC-478
< 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 sen](/manual-img/42/57032/w960_57032-1830.png)
EC-478
< 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-104,
EC-110
Engine coolant temperature sensor circuit
333
EC-121,
EC-129
Air fuel ratio (A/F ) sensor 1 circuit EC-137
,
EC-141
,
EC-145
,
EC-149
,
EC-382
Throttle position sensor circuit 22EC-125
,
EC-188
,
EC-306
,
EC-308
,
EC-374
Accelerator pedal position sensor circuit 3 2 1EC-284
,
EC-367
,
EC-370
,
EC-378
Knock sensor circuit 23EC-198
Crankshaft position sensor (POS) circuit 2 2 EC-201
Camshaft position sensor (PHASE) circuit 3 2 EC-205
Vehicle speed signal circuit2 3 33EC-275
Power steering pressu re sensor circuit 23 3 EC-281
ECM 22333333333 EC-284,
EC-286
Intake valve timing control solenoid valve cir-
cuit 32 13223 3
EC-101
Park/Neutral position (PNP) signal circuit3 3 3 33EC-292
Refrigerant pressure sensor circuit 233 4 EC-419
Electrical load signal circuit 3EC-394
Air conditioner circuit 223333333 3 2 HAC-25
ABS actuator and electric unit (control unit) 4 BRC-36
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: April 20092010 QX56
Page 1832 of 4210
![INFINITI QX56 2010 Factory Service Manual ENGINE CONTROL SYSTEM SYMPTOMSEC-479
< SYMPTOM DIAGNOSIS > [VK56DE]
C
D
E
F
G H
I
J
K L
M A
EC
NP
O
SYMPTOM
Reference
page
HARD/NO START/RESTART (EXCP. HA)
ENGINE STALL
HESITATION/SURGING/FLAT SPOT
S INFINITI QX56 2010 Factory Service Manual ENGINE CONTROL SYSTEM SYMPTOMSEC-479
< SYMPTOM DIAGNOSIS > [VK56DE]
C
D
E
F
G H
I
J
K L
M A
EC
NP
O
SYMPTOM
Reference
page
HARD/NO START/RESTART (EXCP. HA)
ENGINE STALL
HESITATION/SURGING/FLAT SPOT
S](/manual-img/42/57032/w960_57032-1831.png)
ENGINE CONTROL SYSTEM SYMPTOMSEC-479
< SYMPTOM DIAGNOSIS > [VK56DE]
C
D
E
F
G H
I
J
K L
M A
EC
NP
O
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-74
Generator circuit
CHG-6
Starter circuit3 STR-8
Signal plate6 EM-45
Park/Neutral position (PNP) sig-
nal4
TM-45
Engine Cylinder head
55555 55 5 EM-68
Cylinder head gasket 4 3
Cylinder block
66666 66 64
EM-83
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: April 20092010 QX56
Page 1833 of 4210
![INFINITI QX56 2010 Factory Service Manual EC-480
< 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 INFINITI QX56 2010 Factory Service Manual EC-480
< 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](/manual-img/42/57032/w960_57032-1832.png)
EC-480
< 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-9
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: April 20092010 QX56
Page 1836 of 4210
![INFINITI QX56 2010 Factory Service Manual PRECAUTIONSEC-483
< PRECAUTION > [VK56DE]
C
D
E
F
G H
I
J
K L
M A
EC
NP
O
•
Do not disassemble ECM.
• If a battery cable is disconnected, the memory will return to
the ECM value.
The ECM will now INFINITI QX56 2010 Factory Service Manual PRECAUTIONSEC-483
< PRECAUTION > [VK56DE]
C
D
E
F
G H
I
J
K L
M A
EC
NP
O
•
Do not disassemble ECM.
• If a battery cable is disconnected, the memory will return to
the ECM value.
The ECM will now](/manual-img/42/57032/w960_57032-1835.png)
PRECAUTIONSEC-483
< PRECAUTION > [VK56DE]
C
D
E
F
G H
I
J
K L
M A
EC
NP
O
•
Do not disassemble ECM.
• If a battery cable is disconnected, 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 not an indication of a malfunc-
tion. Do not replace parts because 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 disconnecting 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 connecting 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.
• Before replacing ECM, perform ECM Terminals and Reference
Value inspection and make sure ECM functions properly.
Refer to EC-425, "
ECM Terminal and Reference Value" .
• Handle mass air flow sensor carefully to avoid damage.
• Do not disassemble mass air flow sensor.
• Do not clean mass air flow senso r with any type of detergent.
• Do not disassemble electric th rottle control actuator.
• Even a slight leak in the air intake system can cause serious
incidents.
• Do not shock or jar the camsh aft position sensor (PHASE),
crankshaft position sensor (POS).
PBIB1164E
BBIA0387E
PBIB0090E
MEF040D
Revision: April 20092010 QX56
Page 1847 of 4210
![INFINITI QX56 2010 Factory Service Manual EC-494
< ON-VEHICLE REPAIR >[VK56DE]
INTAKE VALVE TIMING CONTROL
INTAKE VALVE TIMING CONTROL
Intake Valve Timing Control Solenoid Valve (LH)INFOID:0000000005149511
REMOVAL
1. Remove engine room cover INFINITI QX56 2010 Factory Service Manual EC-494
< ON-VEHICLE REPAIR >[VK56DE]
INTAKE VALVE TIMING CONTROL
INTAKE VALVE TIMING CONTROL
Intake Valve Timing Control Solenoid Valve (LH)INFOID:0000000005149511
REMOVAL
1. Remove engine room cover](/manual-img/42/57032/w960_57032-1846.png)
EC-494
< ON-VEHICLE REPAIR >[VK56DE]
INTAKE VALVE TIMING CONTROL
INTAKE VALVE TIMING CONTROL
Intake Valve Timing Control Solenoid Valve (LH)INFOID:0000000005149511
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-24, "
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 Intake valve timing co ntrol solenoid valve with a new one, then lubricate
O-ring with engine oil before installing.
Intake Valve Timing Control Solenoid Valve (RH)INFOID:0000000005149512
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 Intake valve timing co ntrol 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: April 20092010 QX56
Page 1848 of 4210
![INFINITI QX56 2010 Factory Service Manual INTAKE VALVE TIMING CONTROLEC-495
< ON-VEHICLE REPAIR > [VK56DE]
C
D
E
F
G H
I
J
K L
M A
EC
NP
O
Intake Valve Timing Control Position Sensor (LH)INFOID:0000000005149513
REMOVAL
1. Remove engine room c INFINITI QX56 2010 Factory Service Manual INTAKE VALVE TIMING CONTROLEC-495
< ON-VEHICLE REPAIR > [VK56DE]
C
D
E
F
G H
I
J
K L
M A
EC
NP
O
Intake Valve Timing Control Position Sensor (LH)INFOID:0000000005149513
REMOVAL
1. Remove engine room c](/manual-img/42/57032/w960_57032-1847.png)
INTAKE VALVE TIMING CONTROLEC-495
< ON-VEHICLE REPAIR > [VK56DE]
C
D
E
F
G H
I
J
K L
M A
EC
NP
O
Intake Valve Timing Control Position Sensor (LH)INFOID:0000000005149513
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:0000000005149514
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:0000000005149515
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 sensor 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: April 20092010 QX56
Page 1849 of 4210
EC-496
< 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: April 20092010 QX56