fuel pressure INFINITI QX4 2005 Factory Manual PDF

DTC P1278, P1288 A/F SENSOR 1
EC-509
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Intake air leaks

Exhaust gas leaks

Incorrect fuel pressure

Lack of fuel

Fuel injector

Incorrect PCV hose connection

PCV valve

Mass air flow sensor
4. Turn ignition switch OFF and wait at least 10 seconds.
5. Start engine and keep the engine speed between 3,500 and 4,000 rpm for at least 1minute under no load.
6. Let engine idle for 1 minute.
7. Increase the engine speed up to 4,000 to 5,000 rpm and keep it for 10 seconds.
8. Fully release accelerator pedal and then let engine idle for about 1 minute.
9. Select Service $07 with GST.
If the 1st trip DTC is displayed, go to EC-513, "
Diagnostic Procedure" .

DTC P1279, P1289 A/F SENSOR 1
EC-519
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DTC P1279, P1289 A/F SENSOR 1PFP:22693
Component DescriptionUBS00HAM
The air fuel ratio (A/F) sensor 1 is a planar dual-cell limit current sen-
sor. The sensor element of the A/F sensor 1 is the combination of a
Nernst concentration cell (sensor cell) with an oxygen-pump cell,
which transports ions. It has a heater in the element.
The sensor is capable of precise measurement = 1, but also in the
lean and rich range. Together with its control electronics, the sensor
outputs a clear, continuous signal throughout a wide range (0.7 <
< air).
The exhaust gas components diffuse through the diffusion gap at the
electrode of the oxygen pump and Nernst concentration cell, where
they are brought to thermodynamic balance.
An electronic circuit controls the pump current through the oxygen-
pump cell so that the composition of the exhaust gas in the diffusion
gap remains constant at = 1. Therefore, the A/F sensor 1 is able to
indicate air/fuel ratio by this pumping of current. In addition, a heater
is integrated in the sensor to ensure the required operating tempera-
ture of 700 - 800°C (1,292 - 1,472°F).
CONSULT-II Reference Value in Data Monitor ModeUBS00HAN
Specification data are reference values.
On Board Diagnosis LogicUBS00HAO
To judge the malfunction of A/F sensor 1, this diagnosis measures response time of the A/F signal computed
by ECM from the A/F sensor 1 signal. The time is compensated by engine operating (speed and load), fuel
feedback control constant, and the A/F sensor 1 temperature index. Judgment is based on whether the com-
pensated time (the A/F signal cycling time index) is inordinately long or not.
SEF 5 79 Z
SEF 5 80 Z
MONITOR ITEM CONDITION SPECIFICATION
A/F SEN1 (B1)
A/F SEN1 (B2)

Engine: After warming upMaintaining engine speed at
2,000 rpmFluctuates around 1.5V
DTC No. Trouble diagnosis name DTC detecting condition Possible Cause
P1279
1279
(Bank 1)
Air fuel ratio (A/F) sensor 1
circuit slow response

The response (from LEAN to RICH) of the A/F
signal computed by ECM from A/F sensor 1
signal takes more than the specified time.

Harness or connectors
(The A/F sensor 1 circuit is open or
shorted.)

Air fuel ratio (A/F) sensor 1

Air fuel ratio (A/F) sensor 1 heater

Fuel pressure

Fuel injector

Intake air leaks

Exhaust gas leaks

PCV

Mass air flow sensor P1289
1289
(Bank 2)

DTC P1279, P1289 A/F SENSOR 1
EC-521
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Revision: October 20052005 QX56

Intake air leaks

Exhaust gas leaks

Incorrect fuel pressure

Lack of fuel

Fuel injector

Incorrect PCV hose connection

PCV valve

Mass air flow sensor
4. Turn ignition switch OFF and wait at least 10 seconds.
5. Start engine and keep the engine speed between 3,500 and 4,000 rpm for at least 1minute under no load.
6. Let engine idle for 1 minute.
7. Increase the engine speed up to 4,000 to 5,000 rpm and keep it for 10 seconds.
8. Fully release accelerator pedal and then let engine idle for about 1 minute.
9. Select Service $07 with GST.
If the 1st trip DTC is displayed, go to EC-525, "
Diagnostic Procedure" .

EC-630Revision: October 2005
IGNITION SIGNAL
2005 QX56
7. Remove fuel pump fuse in fuse block No. 1 to release fuel pres-
sure.
NOTE:
Do not use CONSULT-II to release fuel pressure, or fuel pres-
sure applies again during the following procedure.
8. Start engine.
9. After engine stalls, crank it two or three times to release all fuel
pressure.
10. Turn ignition switch OFF.
11. Remove all ignition coil harness connectors to avoid the electri-
cal discharge from the ignition coils.
12. Remove ignition coil and spark plug of the cylinder to be checked.
13. Crank engine for 5 seconds or more to remove combustion gas in the cylinder.
14. Connect spark plug and harness connector to ignition coil.
15. Fix ignition coil using a rope etc. with gap of 13 - 17 mm
between the edge of the spark plug and grounded metal portion
as shown in the figure.
16. Crank engine for about 3 seconds, and check whether spark is
generated between the spark plug and the grounded metal por-
tion.
CAUTION:

Do not approach to the spark plug and the ignition coil
within 50cm. Be careful not to get an electrical shock
while checking, because the electrical discharge 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.
17. If NG, replace ignition coil with power transistor.
CONDENSER
1. Turn ignition switch OFF.
2. Disconnect condenser harness connector.
3. Check resistance between condenser terminals 1 and 2.
Removal and InstallationUBS00L1E
IGNITION COIL WITH POWER TRANSISTOR
Refer to EM-26, "IGNITION COIL" . Spark should be generated.
BBIA0380E
PBIB2325E
Resistance Above 1 MΩ at 25°C (77°F)
PBIB0794E

FUEL PUMP CIRCUIT
EC-639
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Specification data are reference values and are measured between each terminal and ground.
CAUTION:
Do not use ECM ground terminals when measuring input/output voltage. Doing so may result in dam-
age to the ECM's transistor. Use a ground other than ECM terminals, such as the ground.
Diagnostic ProcedureUBS00HDE
1. CHECK OVERALL FUNCTION
1. Turn ignition switch ON.
2. Pinch fuel feed hose with two fingers.
OK or NG
OK >>INSPECTION END
NG >> GO TO 2.
2. CHECK FUEL PUMP POWER SUPPLY CIRCUIT-I
1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Turn ignition switch ON.
4. Check voltage between ECM terminal 113 and ground with
CONSULT-II or tester.
OK or NG
OK >> GO TO 5.
NG >> GO TO 3.
TER-
MINAL
NO.WIRE
COLORITEM CONDITION DATA (DC Voltage)
113 GR Fuel pump relay[Ignition switch: ON]

For 1 second after turning ignition switch ON
[Engine is running]0 - 1.5V
[Ignition switch: ON]

More than 1 second after turning ignition
switch ON.BATTERY VOLTAGE
(11 - 14V)
Fuel pressure pulsation should be felt on the fuel feed
hose for 1 second after ignition switch is turned ON.
BBIA0357E
Voltage: Battery voltage
PBIB11 87 E

SERVICE DATA AND SPECIFICATIONS (SDS)
EC-669
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SERVICE DATA AND SPECIFICATIONS (SDS)PFP:00030
Fuel PressureUBS00HE9
Idle Speed and Ignition TimingUBS00HEA
*: Under the following conditions:

Air conditioner switch: OFF

Electric load: OFF (Lights and heater fan)

Steering wheel: Kept in straight-ahead position
Calculated Load ValueUBS00HEB
Mass Air Flow SensorUBS00HEC
*: Engine is warmed up to normal operating temperature and running under no load.
Intake Air Temperature SensorUBS00HED
Engine Coolant Temperature SensorUBS00HEE
A/F Sensor 1 HeaterUBS00HEF
Heated Oxygen sensor 2 HeaterUBS00HEG
Crankshaft Position Sensor (POS)UBS00HEH
Refer to EC-290, "Component Inspection" .
Camshaft Position Sensor (PHASE)UBS00HEI
Refer to EC-297, "Component Inspection" .
Throttle Control MotorUBS00HEJ
Fuel pressure at idling kPa (kg/cm2 , psi)Approximately 350 (3.57, 51)
Target idle speed
No-load* (in P or N position)650±50 rpm
Air conditioner: ON In P or N position 700 rpm or more
Ignition timing In P or N position 15° ± 5° BTDC
Condition Calculated load value % (Using CONSULT-II or GST)
At idle14.0 - 33.0
At 2,500 rpm12.0 - 25.0
Supply voltage Battery voltage (11 - 14V)
Output voltage at idle1.0 - 1.3V*
Mass air flow (Using CONSULT-II or GST)3.0 - 9.0 g·m/sec at idle*
9.0 - 28.0 g·m/sec at 2,500 rpm*
Temperature °C (°F) Resistance kΩ
25 (77)1.94 - 2.06
80 (176)0.295 - 0.349
Temperature °C (°F) Resistance kΩ
20 (68)2.1 - 2.9
50 (122)0.68 - 1.00
90 (194)0.236 - 0.260
Resistance [at 25°C (77°F)] 2.3 - 4.3Ω
Resistance [at 25°C (77°F)] 5.0 - 7.0Ω
Resistance [at 25°C (77°F)] Approximately 1 - 15Ω

PRECAUTIONS
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PRECAUTIONSPFP:00001
Precautions for Drain Engine CoolantEBS00LLK
Drain engine coolant when engine is cooled.
Precautions for Disconnecting Fuel PipingEBS00LLL

Before starting work, make sure no fire or spark producing items are in the work area.

Release fuel pressure before disconnecting and disassembly.

After disconnecting pipes, plug openings to stop fuel leakage.
Precautions for Removal and DisassemblyEBS00LLM

When instructed to use special service tools, use the specified tools. Always be careful to work safely,
avoid forceful or uninstructed operations.

Exercise maximum care to avoid damage to mating or sliding surfaces.

Cover openings of engine system with tape or the equivalent, if necessary, to seal out foreign materials.

Mark and arrange disassembly parts in an organized way for easy troubleshooting and assembly.

When loosening nuts and bolts, as a basic rule, start with the one furthest outside, then the one diagonally
opposite, and so on. If the order of loosening is specified, do exactly as specified. Power tools may be
used where noted in the step.
Precautions for Inspection, Repair and ReplacementEBS00LLN
Before repairing or replacing, thoroughly inspect parts. Inspect new replacement parts in the same way, and
replace if necessary.
Precautions for Assembly and InstallationEBS00LLO

Use torque wrench to tighten bolts or nuts to specification.

When tightening nuts and bolts, as a basic rule, equally tighten in several different steps starting with the
ones in center, then ones on inside and outside diagonally in this order. If the order of tightening is speci-
fied, do exactly as specified.

Replace with new gasket, packing, oil seal or O-ring.

Thoroughly wash, clean, and air-blow each part. Carefully check engine oil or engine coolant passages for
any restriction and blockage.

Avoid damaging sliding or mating surfaces. Completely remove foreign materials such as cloth lint or dust.
Before assembly, oil sliding surfaces well.

Release air within route when refilling after draining engine coolant.

Before starting engine, apply fuel pressure to fuel lines with turning ignition switch ON (with engine
stopped). Then make sure that there are no leaks at fuel line connections.

After repairing, start engine and increase engine speed to check engine coolant, fuel, oil, and exhaust
systems for leakage.
Parts Requiring Angular TighteningEBS00LLP

For final tightening of the following engine parts use Tool:
–Cylinder head bolts
–Main bearing cap bolts
–Connecting rod cap bolts
–Crankshaft pulley bolt (No angle wrench is required as the bolt flange is provided with notches for angle
tightening)

Do not use a torque value for final tightening.

The torque value for these parts are for a preliminary step.

Ensure thread and seat surfaces are clean and lightly coated with engine oil. Tool number : KV10112100 (BT-8653-A)

PREPARATION
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PREPARATIONPFP:00002
Special Service ToolsEBS00LLR
The actual shapes of Kent-Moore tools may differ from those of special service tools illustrated here.
Tool number
(Kent-Moore No.)
Tool nameDescription
KV10111100
(J-37228)
Seal cutterRemoving steel oil pan and rear timing chain
case
—
(J-44626)
Air fuel sensor SocketLoosening or tightening air fuel ratio A/F sen-
sor
a: 22 mm (0.87 in)
EG15050500
(J-45402)
Compression gauge adapterInspecting compression pressure
KV10116200
(J-26336-A)
Valve spring compressor
1. KV10115900
(J-26336-20)
Attachment
2. KV10109220
(—)
AdapterDisassembling valve mechanism
Part (1) is a component of KV10116200
(J26336-A), but part (2) is not.
KV10112100
(BT-8653-A)
Angle wrenchTightening bolts for cylinder head, main bear-
ing cap and connecting rod cap
KV10107902
(J-38959)
Valve oil seal pullerRemoving valve oil seal
S-NT046
LBIA0444E
ZZA1225D
PBIC1650E
S-NT014
S-NT011

INTAKE MANIFOLD
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INTAKE MANIFOLDPFP:14003
Removal and InstallationEBS00LM1
REMOVAL
1. Partially drain the engine coolant. Refer to MA-13, "DRAINING ENGINE COOLANT" .
WAR NIN G:
To avoid the danger of being scalded, never drain the engine coolant when the engine is hot.
2. Remove the engine room cover using power tool. Refer to EM-11, "
REMOVAL" .
3. Release the fuel pressure. Refer to EC-93, "
FUEL PRESSURE RELEASE" .
4. Remove the air duct and resonator assembly. Refer to EM-14, "
REMOVAL" .
5. Disconnect the fuel tube quick connector on the engine side.
1. Intake manifold 2. PCV hose 3. Gasket
4. Electric throttle control actuator 5. Water hose 6. Water hose
7. PCV hose 8. EVAP hose 9. EVAP canister purge control sole-
noid valve
10. Bracket 11. Gasket
KBIA2461E
LBIA0395E

EM-18Revision: October 2005
INTAKE MANIFOLD
2005 QX56
5. Install the quick connector cap on the quick connector joint (on
engine side only).
6. Install the fuel hose and tube to hose clamps.
7. Refill the engine coolant. Refer to MA-14, "
REFILLING ENGINE
COOLANT" .
INSPECTION AFTER INSTALLATION

After installing fuel tubes, make sure there is no fuel leakage at connections in the following steps.
–Apply fuel pressure to fuel lines by turning ignition switch ON (with engine stopped). Then check for fuel
leaks at connections.
–Start the engine and rev it up and check for fuel leaks at the connections.

Perform procedures for “Throttle Valve Closed Position Learning” after finishing repairs. Refer to EC-90,
"Throttle Valve Closed Position Learning" .

If electric throttle control actuator is replaced, perform procedures for “Idle Air Volume Learning” after fin-
ishing repairs. Refer to EC-91, "
Idle Air Volume Learning" .
SBIA0354E