timing INFINITI QX4 2001 Factory User Guide

Possible Cause ........................................................ 411
Overall Function Check ........................................... 411
DTC P0464 FUEL LEVEL SENSOR CIRCUIT...........413
Component Description ...........................................413
On Board Diagnostic Logic......................................413
Possible Cause ........................................................413
DTC Confirmation Procedure ..................................413
Wiring Diagram ........................................................414
Diagnostic Procedure ..............................................415
DTC P0500 VEHICLE SPEED SENSOR (VSS).........417
Component Description ...........................................417
ECM Terminals and Reference Value .....................417
On Board Diagnosis Logic.......................................417
Possible Cause ........................................................418
DTC Confirmation Procedure ..................................418
Overall Function Check ...........................................418
Wiring Diagram ........................................................420
Diagnostic Procedure ..............................................421
DTC P0505 IDLE AIR CONTROL VALVE (IACV) -
AUXILIARY AIR CONTROL (AAC) VALVE...............422
Description ...............................................................422
CONSULT-II Reference Value in Data Monitor
Mode ........................................................................423
ECM Terminals and Reference Value .....................423
On Board Diagnosis Logic.......................................423
Possible Cause ........................................................423
DTC Confirmation Procedure ..................................423
Wiring Diagram ........................................................425
Diagnostic Procedure ..............................................426
DTC P0510 CLOSED THROTTLE POSITION
SWITCH.......................................................................431
Component Description ...........................................431
CONSULT-II Reference Value in Data Monitor
Mode ........................................................................431
ECM Terminals and Reference Value .....................431
On Board Diagnosis Logic.......................................431
Possible Cause ........................................................431
DTC Confirmation Procedure ..................................432
Overall Function Check ...........................................432
Wiring Diagram ........................................................434
Diagnostic Procedure ..............................................435
DTC P0600 A/T COMMUNICATION LINE..................440
System Description ..................................................440
ECM Terminals and Reference Value .....................440
On Board Diagnosis Logic.......................................440
Possible Cause ........................................................440
DTC Confirmation Procedure ..................................440
Wiring Diagram ........................................................442
Diagnostic Procedure ..............................................443
DTC P0605 ECM.........................................................444
Component Description ...........................................444
On Board Diagnosis Logic.......................................444Possible Cause ........................................................444
DTC Confirmation Procedure ..................................444
Diagnostic Procedure ..............................................445
DTC P1110 (RIGHT, -B1), P1135 (LEFT, -B2)
INTAKE VALVE TIMING CONTROL..........................446
Description ...............................................................446
CONSULT-II Reference Value in Data Monitor
Mode ........................................................................446
ECM Terminals and Reference Value .....................447
On Board Diagnosis Logic.......................................448
Possible Cause ........................................................448
DTC Confirmation Procedure ..................................449
D T C P 1111(RIGHT, -B1), P1136 (LEFT, -B2)
INTAKE VALVE TIMING CONTROL SOLENOID
VALVE (CIRCUIT)........................................................451
Component Description ...........................................451
CONSULT-II Reference Value in Data Monitor
Mode ........................................................................451
ECM Terminals and Reference Value .....................451
On Board Diagnosis Logic.......................................452
Possible Cause ........................................................452
DTC Confirmation Procedure ..................................452
Wiring Diagram ........................................................453
Diagnostic Procedure ..............................................455
DTC P1130 SWIRL CONTROL VALVE CONTROL
SOLENOID VALVE......................................................458
Description ...............................................................458
CONSULT-II Reference Value in Data Monitor
Mode ........................................................................459
ECM Terminals and Reference Value .....................459
On Board Diagnosis Logic.......................................459
Possible Cause ........................................................460
DTC Confirmation Procedure ..................................460
Wiring Diagram ........................................................462
Diagnostic Procedure ..............................................463
DTC P1140 (RIGHT, -B1), P1145 (LEFT, -B2)
INTAKE VALVE TIMING CONTROL POSITION
SENSOR (CIRCUIT)....................................................482
Component Description ...........................................482
CONSULT-II Reference Value in Data Monitor
Mode ........................................................................482
ECM Terminals and Reference Value .....................482
On Board Diagnosis Logic.......................................483
Possible Cause ........................................................483
DTC Confirmation Procedure ..................................483
Wiring Diagram ........................................................485
Diagnostic Procedure ..............................................487
DTC P1148 (RIGHT BANK, -B1), P1168 (LEFT
BANK, -B2) CLOSED LOOP CONTROL...................491
On Board Diagnosis Logic.......................................491
Possible Cause ........................................................491
DTC Confirmation Procedure ..................................491GI
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CONTENTS(Cont'd)
EC-5

CONSULT-II Reference Value in Data Monitor
Mode ........................................................................585
ECM Terminals and Reference Value .....................585
On Board Diagnosis Logic.......................................586
Possible Cause ........................................................586
DTC Confirmation Procedure ..................................586
Wiring Diagram ........................................................587
Diagnostic Procedure ..............................................588
DTC P1491 VACUUM CUT VALVE BYPASS
VALVE..........................................................................591
Description ...............................................................591
CONSULT-II Reference Value in Data Monitor
Mode ........................................................................591
ECM Terminals and Reference Value .....................591
On Board Diagnosis Logic.......................................592
Possible Cause ........................................................592
DTC Confirmation Procedure ..................................592
Overall Function Check ...........................................593
Wiring Diagram ........................................................594
Diagnostic Procedure ..............................................595
DTC P1605 A/T DIAGNOSIS COMMUNICATION
LINE.............................................................................603
Component Description ...........................................603
On Board Diagnosis Logic.......................................603
Possible Cause ........................................................603
DTC Confirmation Procedure ..................................603
DTC P1706 PARK/NEUTRAL POSITION (PNP)
SWITCH.......................................................................604
Component Description ...........................................604
CONSULT-II Reference Value in Data Monitor
Mode ........................................................................604
ECM Terminals and Reference Value .....................604
On Board Diagnosis Logic.......................................604
Possible Cause ........................................................604
DTC Confirmation Procedure ..................................605
Overall Function Check ...........................................606
Wiring Diagram ........................................................607
Diagnostic Procedure ..............................................608
VARIABLE INDUCTION AIR CONTROL SYSTEM
(VIAS)...........................................................................610
Description ...............................................................610
ECM Terminals and Reference Value ..................... 611
Wiring Diagram ........................................................612
Diagnostic Procedure ..............................................613
INJECTOR...................................................................616
Component Description ...........................................616
CONSULT-II Reference Value in Data Monitor
Mode ........................................................................616
ECM Terminals and Reference Value .....................616
Wiring Diagram ........................................................617Diagnostic Procedure ..............................................618
START SIGNAL...........................................................621
CONSULT-II Reference Value in Data Monitor
Mode ........................................................................621
ECM Terminals and Reference Value .....................621
Wiring Diagram ........................................................622
Diagnostic Procedure ..............................................623
FUEL PUMP.................................................................625
System Description ..................................................625
Component Description ...........................................625
CONSULT-II Reference Value in Data Monitor
Mode ........................................................................625
ECM Terminals and Reference Value .....................626
Wiring Diagram ........................................................627
Diagnostic Procedure ..............................................628
POWER STEERING OIL PRESSURE SWITCH.........634
Component Description ...........................................634
CONSULT-II Reference Value in Data Monitor
Mode ........................................................................634
ECM Terminals and Reference Value .....................634
Wiring Diagram ........................................................635
Diagnostic Procedure ..............................................636
REFRIGERANT PRESSURE SENSOR......................639
Description ...............................................................639
ECM Terminals and Reference Value .....................639
Wiring Diagram ........................................................640
Diagnostic Procedure ..............................................641
ELECTRICAL LOAD SIGNAL.....................................643
ECM Terminals and Reference Value .....................643
Wiring Diagram ........................................................644
Diagnostic Procedure ..............................................645
MIL & DATA LINK CONNECTORS............................648
Wiring Diagram ........................................................648
SERVICE DATA AND SPECIFICATIONS (SDS).......649
Fuel Pressure Regulator..........................................649
Idle Speed and Ignition Timing ................................649
Mass Air Flow Sensor..............................................649
Engine Coolant Temperature Sensor ......................649
Heated Oxygen Sensor 1 Heater (Front) ................649
Fuel Pump ...............................................................649
IACV-AAC Valve ......................................................649
Injector .....................................................................649
Resistor ....................................................................649
Throttle Position Sensor ..........................................650
Calculated Load Value.............................................650
Intake Air Temperature Sensor ................................650
Heated Oxygen Sensor 2 Heater (Rear).................650
Crankshaft Position Sensor (REF) ..........................650
Fuel Tank Temperature Sensor ...............................650
Camshaft Position Sensor (PHASE) .......................650GI
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CONTENTS(Cont'd)
EC-7

Fuel Injection TimingNBEC0014S07
SEF179U
Two types of systems are used.
Sequential Multiport Fuel Injection System
NBEC0014S0701Fuel is injected into each cylinder during each engine cycle according to the firing order. This system is used
when the engine is running.
Simultaneous Multiport Fuel Injection System
NBEC0014S0702Fuel is injected simultaneously into all six cylinders twice each engine cycle. In other words, pulse signals of
the same width are simultaneously transmitted from the ECM.
The six injectors will then receive the signals two times for each engine cycle.
This system is used when the engine is being started and/or if the fail-safe system (CPU) is operating.
Fuel Shut-offNBEC0014S08Fuel to each cylinder is cut off during deceleration or operation of the engine at excessively high speeds.
Electronic Ignition (EI) System
DESCRIPTIONNBEC0015Input/Output Signal ChartNBEC0015S01
Sensor Input Signal to ECMECM func-
tionActuator
Crankshaft position sensor (POS) Engine speed (POS signal)
Ignition
timing con-
trolPower transistor Crankshaft position sensor (REF) Engine speed (REF signal)
Camshaft position sensor (PHASE) Piston position
Mass air flow sensor Amount of intake air
Engine coolant temperature sensor Engine coolant temperature
Throttle position sensorThrottle position
Throttle valve idle position
Vehicle speed sensor Vehicle speed
Ignition switch Start signal
Knock sensor Engine knocking
Park/neutral position (PNP) switch Gear position
Battery Battery voltage
ENGINE AND EMISSION BASIC CONTROL SYSTEM DESCRIPTION
Multiport Fuel Injection (MFI) System (Cont'd)
EC-30

System DescriptionNBEC0015S02
SEF742M
The ignition timing is controlled by the ECM to maintain the best air-fuel ratio for every running condition of
the engine. The ignition timing data is stored in the ECM. This data forms the map shown.
The ECM receives information such as the injection pulse width and camshaft position sensor signal. Com-
puting this information, ignition signals are transmitted to the power transistor.
e.g., N: 1,800 rpm, Tp: 1.50 msec
A ÉBTDC
During the following conditions, the ignition timing is revised by the ECM according to the other data stored
in the ECM.
IAt starting
IDuring warm-up
IAt idle
IAt low battery voltage
IDuring acceleration
The knock sensor retard system is designed only for emergencies. The basic ignition timing is programmed
within the anti-knocking zone, if recommended fuel is used under dry conditions. The retard system does not
operate under normal driving conditions. If engine knocking occurs, the knock sensor monitors the condition.
The signal is transmitted to the ECM. The ECM retards the ignition timing to eliminate the knocking condition.
Air Conditioning Cut Control
DESCRIPTIONNBEC0016Input/Output Signal ChartNBEC0016S01
Sensor Input Signal to ECM ECM function Actuator
Air conditioner switch Air conditioner ªONº signal
Air conditioner
cut controlAir conditioner relay Throttle position sensor Throttle valve opening angle
Crankshaft position sensor (POS) Engine speed (POS signal)
Crankshaft position sensor (REF) Engine speed (REF signal)
Engine coolant temperature sensor Engine coolant temperature
Ignition switch Start signal
Vehicle speed sensor Vehicle speed
Refrigerant pressure sensor Refrigerant pressure
Power steering oil pressure switch Power steering operation
System DescriptionNBEC0016S02This system improves engine operation when the air conditioner is used.
Under the following conditions, the air conditioner is turned off.
IWhen the accelerator pedal is fully depressed.
IWhen cranking the engine.
IAt high engine speeds.
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ENGINE AND EMISSION BASIC CONTROL SYSTEM DESCRIPTION
Electronic Ignition (EI) System (Cont'd)
EC-31

SEF937Y
SEF703X
Injector
REMOVAL AND INSTALLATIONNBEC00261. Release fuel pressure to zero.
2. Remove intake manifold collector. Refer to EM-20, ªTIMING
CHAINº.
3. Remove fuel tube assemblies in numerical sequence as
shown in the figure at left.
4. Expand and remove clips securing fuel injectors.
5. Extract fuel injectors straight from fuel tubes.
IBe careful not to damage injector nozzles during removal.
IDo not bump or drop fuel injectors.
6. Carefully install O-rings, including the one used with the pres-
sure regulator.
ILubricate O-rings with a smear of engine oil.
IBe careful not to damage O-rings with service tools, fin-
ger nails or clips. Do not expand or twist O-rings.
IDiscard old clips; replace with new ones.
7. Position clips in grooves on fuel injectors.
IMake sure that protrusions of fuel injectors are aligned
with cutouts of clips after installation.
SEF938Y
8. Align protrusions of fuel tubes with those of fuel injectors.
Insert fuel injectors straight into fuel tubes.
9. After properly inserting fuel injectors, check to make sure that
fuel tube protrusions are engaged with those of fuel injectors,
and that flanges of fuel tubes are engaged with clips.
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BASIC SERVICE PROCEDURE
Injector
EC-41

SEF939Y
10. Tighten fuel tube assembly mounting nuts in numerical
sequence (indicated in the figure at left) and in two stages.
: Tightening torque N´m (kg-m, ft-lb)
1st stage:
9.3 - 10.8 (1.0 - 1.1, 6.9 - 7.9)
2nd stage:
20.6 - 26.5 (2.1 - 2.7, 16 - 19)
11. Install all parts removed in reverse order of removal.
CAUTION:
After properly connecting fuel tube assembly to injector and
fuel hose, check connection for fuel leakage.
SEF058Y
How to Check Idle Speed and Ignition TimingNBEC0607IDLE SPEEDNBEC0607S01IUsing CONSULT-II
Check idle speed in ªDATA MONITORº mode with CONSULT-II.
SEF940Y
IGNITION TIMINGNBEC0607S02Any of following two methods may be used.
IMethod A
a) Attach timing light to loop wire as shown.
b) Check ignition timing.
SEF942Y
IMethod B
a) Remove No. 1 ignition coil.
BASIC SERVICE PROCEDURE
Injector (Cont'd)
EC-42

SEF943Y
SEF572X
b) Connect No. 1 ignition coil and No. 1 spark plug with suitable
high-tension wire as shown, and attach timing light clamp to
this wire.
c) Check ignition timing.
SEF311Q
Idle Speed/Ignition Timing/Idle Mixture Ratio
Adjustment
NBEC0028PREPARATIONNBEC0028S011) Make sure that the following parts are in good order.
IBattery
IIgnition system
IEngine oil and coolant levels
IFuses
IECM harness connector
IVacuum hoses
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BASIC SERVICE PROCEDURE
How to Check Idle Speed and Ignition Timing (Cont'd)
EC-43

IAir intake system
(Oil filler cap, oil level gauge, etc.)
IFuel pressure
IEngine compression
IThrottle valve
IEvaporative emission system
2) On air conditioner equipped models, checks should be carried out while the air conditioner is ªOFFº.
3) On automatic transmission equipped models, when checking idle rpm, ignition timing and mixture ratio,
checks should be carried out while shift lever is in ªNº position.
4) When measuring ªCOº percentage, insert probe more than 40 cm (15.7 in) into tail pipe.
5) Turn off headlamps, heater blower, rear defogger.
6) Keep front wheels pointed straight ahead.
7) Make the check after the cooling fan has stopped.
BASIC SERVICE PROCEDURE
Idle Speed/Ignition Timing/Idle Mixture Ratio Adjustment (Cont'd)
EC-44

Overall Inspection SequenceNBEC0028S0101
SEC141C
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BASIC SERVICE PROCEDURE
Idle Speed/Ignition Timing/Idle Mixture Ratio Adjustment (Cont'd)
EC-45

INSPECTION PROCEDURE=NBEC0028S02
1 INSPECTION START
1. Visually check the following:
IAir cleaner clogging
IHoses and ducts for leaks
IElectrical connectors
IGasket
IThrottle valve and throttle position sensor operation
2. Start engine and warm it up until engine coolant temperature indicator points to the middle of gauge.
Ensure engine stays below 1,000 rpm.
SEF976U
3. Open engine hood and run engine at about 2,000 rpm for about 2 minutes under no-load.
SEF977U
4. Make sure that no DTC is displayed with CONSULT-II or GST.
OK or NG
OK©GO TO 3.
NG©GO TO 2.
2 REPAIR OR REPLACE
Repair or replace components as necessary according to corresponding ªDiagnostic Procedureº.
©GO TO 3.
3 CHECK TARGET IDLE SPEED
With CONSULT-II
1. Start engine and warm it up to normal operating temperature.
2. Select ªENG SPEEDº in ªDATA MONITORº mode with CONSULT-II.
3. Check idle speed.
750±50 rpm (in ªPº or ªNº position)
Without CONSULT-II
1. Start engine and warm it up to normal operating temperature.
2. Check idle speed.
750±50 rpm (in ªPº or ªNº position)
OK or NG
OK©GO TO 12.
NG©GO TO 4.
BASIC SERVICE PROCEDURE
Idle Speed/Ignition Timing/Idle Mixture Ratio Adjustment (Cont'd)
EC-46