ENGINE CONTROL SYSTEM SYMPTOMSEC-479
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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-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
NORMAL OPERATING CONDITIONEC-481
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NORMAL OPERATING CONDITION
Fuel Cut Control (at No
Load and High Engine Speed)INFOID:0000000005149501
INPUT/OUTPUT SIGNAL CHART
*: This signal is sent to the ECM through CAN communication line.
SYSTEM DESCRIPTION
If the engine speed is above 1,800 rpm under no load (for example, the shift position is neutral and engine
speed over is 1,800 rpm) fuel will be cut off after some time. The exact time when the fuel is cut off varies
based on engine speed.
Fuel cut will be operated until the engine speed reaches 1,500 rpm, then fuel cut will be cancelled.
NOTE:
This function is different from deceleration control listed under EC-28, "
System Description".
Sensor Input signal to ECMECM functionActuator
TCM Neutral position
Fuel cut control Fuel injector
Accelerator pedal position sensor
Accelerator pedal position
Engine coolant temperature sensor Engine coolant temperature
Crankshaft position sensor (POS)
Camshaft position sensor (PHASE) Engine speed
Wheel sensor Vehicle speed*
Revision: April 20092010 QX56
EC-482
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PRECAUTIONS
PRECAUTION
PRECAUTIONS
Precaution for Supplemental Restraint Syst
em (SRS) "AIR BAG" and "SEAT BELT
PRE-TENSIONER"
INFOID:0000000005149502
The Supplemental Restraint System such as “A IR BAG” and “SEAT BELT PRE-TENSIONER”, used along
with a front seat belt, helps to reduce the risk or severity of injury to the driver and front passenger for certain
types of collision. This system includes seat belt switch inputs and dual stage front air bag modules. The SRS
system uses the seat belt switches to determine the front air bag deployment, and may only deploy one front
air bag, depending on the severity of a collision and w hether the front occupants are belted or unbelted.
Information necessary to service the system safely is included in the SRS and SB section of this Service Man-
ual.
WARNING:
• To avoid rendering the SRS inopera tive, which could increase the risk of personal injury or death in
the event of a collision which would result in air bag inflation, all maintenance must be performed by
an authorized NISSAN/INFINITI dealer.
• Improper maintenance, including in correct removal and installation of the SRS, can lead to personal
injury caused by unintent ional activation of the system. For re moval of Spiral Cable and Air Bag
Module, see the SRS section.
• Do not use electrical test equipmen t on any circuit related to the SRS unless instructed to in this
Service Manual. SRS wiring harn esses can be identified by yellow and/or orange harnesses or har-
ness connectors.
On Board Diagnosis (OBD) S ystem of Engine and A/TINFOID:0000000005149503
The ECM has an on board diagnostic system. It will light up the malfunction indicator lamp (MIL) to warn the
driver of a malfunction causing emission deterioration.
CAUTION:
• Be sure to turn the ignition switch OFF and disconnect the negative battery cable before any repair
or inspection work. The open/short circuit of re lated switches, sensors, solenoid valves, etc. will
cause the MIL to light up.
• Be sure to connect and lock the connectors secure ly after work. A loose (unlocked) connector will
cause the MIL to light up due to the open circuit. (Be sure the connector is free from water, grease,
dirt, bent terminals, etc.)
• Certain systems and components, especially those related to OBD, may use a new style slide-lock-
ing type harness connector. For descrip tion and how to disconnect, refer to PG-64
.
• Be sure to route and secure the harnesses properly after work. The interference of the harness with
a bracket, etc. may cause the MIL to li ght up due to the short circuit.
• Be sure to connect rubber tubes properly afte r work. A misconnected or disconnected rubber tube
may cause the MIL to light up due to the malfunction of the EVAP system or fuel injection system,
etc.
• Be sure to erase the unnecessary malfunction info rmation (repairs completed) from the ECM and
TCM (Transmission control module) before returning the vehicle to the customer.
PrecautionINFOID:0000000005149504
•Always use a 12 volt battery as power source.
• Do not attempt to disconnect battery cables while engine is
running.
• Before connecting or disconnecting 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.
SEF289H
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PRECAUTIONSEC-483
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•
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
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EC-486
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PREPARATION
PREPARATION
PREPARATION
Special Service ToolINFOID:0000000005149505
The actual shapes of Kent-Moore tool
s may differ from those of special service tools illustrated here.
Tool number
(Kent-Moore No.)
Tool nameDescription
EG17650301
(J-33984-A)
Radiator cap tester
adapter Adapting radiator cap tester to radiator cap and ra-
diator filler neck
a: 28 (1.10) dia.
b: 31.4 (1.236) dia.
c: 41.3 (1.626) dia.
Unit: mm (in)
KV10117100
(J-36471-A)
Heated oxygen sensor
wrench Loosening or tightening heated oxygen sensors
with 22 mm (0.87 in) hexagon nut
KV10114400
(J-38365)
Heated oxygen sensor
wrench Loosening or tightening heated oxygen sensors
a: 22 mm (0.87 in)
(J-44626)
Air fuel ratio (A/F) sen-
sor wrench Loosening or tightening air fuel ratio (A/F) sensor 1
(J-44321)
Fuel pressure gauge
kit Checking fuel pressure
(J-44321-6)
Fuel pressure adapter Connecting fuel pressure gauge to quick connec-
tor type fuel lines.
S-NT564
S-NT379
S-NT636
LEM054
LEC642
LBIA0376E
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PREPARATIONEC-487
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Commercial Service ToolINFOID:0000000005149506
(J-45488)
Quick connector re-
lease
Remove fuel tube quick connectors in engine
room.
(J-23688)
Engine coolant refrac-
tometer Checking concentration of ethylene glycol in en-
gine coolant
Tool number
(Kent-Moore No.)
Tool name
Description
PBIC0198E
WBIA0539E
Tool name
(Kent-Moore No.)
Description
Leak detector
i.e.: (J-41416) Locating the EVAP leak
EVAP service port
adapter
i.e.: (J-41413-OBD) Applying positive pressure through EVAP service
port
Fuel filler cap adapter
i.e.: (MLR-8382) Checking fuel tank vacuum relief valve opening
pressure
Socket wrench Removing and installing engine coolant tempera-
ture sensor
S-NT703
S-NT704
S-NT815
S-NT705
Revision: April 20092010 QX56
EC-488
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PREPARATION
Oxygen sensor thread
cleaner
i.e.: (J-43897-18)
(J-43897-12)Reconditioning the exhaust system threads before
installing a new oxygen sensor. Use with anti-
seize lubricant shown below.
a: 18 mm diameter with pitch 1.5 mm for Zirco-
nia Oxygen Sensor
b: 12 mm diameter with pitch 1.25 mm for Tita-
nia Oxygen Sensor
Anti-seize lubricant
i.e.: (Permatex
TM
133AR or equivalent
meeting MIL specifica-
tion MIL-A-907) Lubricating oxygen sensor thread cleaning tool
when reconditioning exhaust system threads.
Tool name
(Kent-Moore No.)
Description
AEM488
S-NT779
Revision: April 20092010 QX56
INTAKE VALVE TIMING CONTROLEC-495
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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