2008 INFINITI FX35 air condition

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CONTENTS
ENGINE CONTROL SYSTEM
VQ35DE
SERVICE INFORMATION .. .........................
17
INDEX FOR DTC ............................................ ....17
DTC No. Index .................................................... ....17
Alphabetical Index ...................................................20
PRECAUTIONS ..................................................25
Precaution for Supplemental Restraint System
(SRS) "AIR BAG" and "SEAT BELT PRE-TEN-
SIONER" ............................................................. ....
25
Precaution for Procedure without Cowl Top Cover ....25
On Board Diagnosis (OBD) System of Engine and
A/T ...........................................................................
25
Precaution ...............................................................26
PREPARATION ..................................................29
Special Service Tool ........................................... ....29
Commercial Service Tool ........................................30
ENGINE CONTROL SYSTEM ............................31
Schematic ........................................................... ....31
Multiport Fuel Injection (MFI) System .....................31
Electronic Ignition (EI) System ................................34
Fuel Cut Control (at No Load and High Engine
Speed) .....................................................................
34
AIR CONDITIONING CUT CONTROL ...............36
Input/Output Signal Chart .................................... ....36
System Description .................................................36
AUTOMATIC SPEED CONTROL DEVICE
(ASCD) ...............................................................
37
System Description ............................................. ....37
Component Description ...........................................38
CAN COMMUNICATION ....................................39
System Description ............................................. ....39
EVAPORATIVE EMISSION SYSTEM ................40
Description .......................................................... ....40
Component Inspection ......................................... ....42
Removal and Installation .........................................44
How to Detect Fuel Vapor Leakage .........................44
ON BOARD REFUELING VAPOR RECOV-
ERY (ORVR) ......................................................
46
System Description ..................................................46
Diagnosis Procedure ...............................................46
Component Inspection .............................................48
POSITIVE CRANKCASE VENTILATION .........51
Description ...............................................................51
Component Inspection .............................................51
IVIS (INFINITI VEHICLE IMMOBILIZER SYS-
TEM-NATS) .......................................................
53
Description ...............................................................53
ON BOARD DIAGNOSTIC (OBD) SYSTEM ....54
Introduction ..............................................................54
Two Trip Detection Logic .........................................54
Emission-Related Diagnostic Information ................55
Malfunction Indicator Lamp (MIL) ............................71
OBD System Operation Chart .................................74
BASIC SERVICE PROCEDURE .......................80
Basic Inspection ......................................................80
Idle Speed and Ignition Timing Check .....................84
Procedure After Replacing ECM .............................84
VIN Registration ......................................................84
Accelerator Pedal Released Position Learning .......85
Throttle Valve Closed Position Learning .................85
Idle Air Volume Learning .........................................85
Fuel Pressure Check ...............................................87
TROUBLE DIAGNOSIS ....................................89
Trouble Diagnosis Introduction ................................89
DTC Inspection Priority Chart ..................................93
Fail-Safe Chart ........................................................95
Symptom Matrix Chart .............................................96
Engine Control Component Parts Location ...........100
Vacuum Hose Drawing ..........................................106
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EC-8
Component Inspection ...........................................545
ASCD INDICATOR ..........................................547
Component Description ....................................... ..547
CONSULT-III Reference Value in Data Monitor
Mode .................................................................... ..
547
Wiring Diagram ......................................................548
Diagnosis Procedure .............................................548
ELECTRICAL LOAD SIGNAL .........................550
Description ........................................................... ..550
CONSULT-III Reference Value in Data Monitor
Mode .................................................................... ..
550
Diagnosis Procedure .............................................550
FUEL INJECTOR .............................................552
Component Description ....................................... ..552
CONSULT-III Reference Value in Data Monitor
Mode .................................................................... ..
552
Wiring Diagram ......................................................553
Diagnosis Procedure .............................................554
Component Inspection ...........................................557
Removal and Installation .......................................557
FUEL PUMP .....................................................558
Description ........................................................... ..558
CONSULT-III Reference Value in Data Monitor
Mode .................................................................... ..
558
Wiring Diagram ......................................................559
Diagnosis Procedure .............................................560
Component Inspection ...........................................562
Removal and Installation .......................................562
ICC BRAKE SWITCH ......................................563
Component Description ....................................... ..563
CONSULT-III Reference Value in Data Monitor
Mode .................................................................... ..
563
Wiring Diagram ......................................................564
Diagnosis Procedure .............................................565
Component Inspection ...........................................567
IGNITION SIGNAL ...........................................569
Component Description ....................................... ..569
Wiring Diagram ......................................................570
Diagnosis Procedure .............................................575
Component Inspection ...........................................578
Removal and Installation .......................................580
REFRIGERANT PRESSURE SENSOR ..........581
Component Description ....................................... ..581
Wiring Diagram ......................................................582
Diagnosis Procedure .............................................583
Removal and Installation .......................................585
SNOW MODE SWITCH ...................................586
Description ........................................................... ..586
CONSULT-III Reference Value in Data Monitor
Mode .................................................................... ..
586
Wiring Diagram ......................................................587
Diagnosis Procedure .............................................587
Component Inspection ...........................................589
MIL AND DATA LINK CONNECTOR ...............591
Wiring Diagram .................................................... .591
SERVICE DATA AND SPECIFICATIONS
(SDS) ................................................................
593
Fuel Pressure ....................................................... .593
Idle Speed and Ignition Timing .............................593
Calculated Load Value ..........................................593
Mass Air Flow Sensor ...........................................593
Intake Air Temperature Sensor .............................593
Engine Coolant Temperature Sensor ...................593
Air Fuel Ratio (A/F) Sensor 1 Heater ....................593
Heated Oxygen sensor 2 Heater ..........................593
Crankshaft Position Sensor (POS) .......................594
Camshaft Position Sensor (PHASE) .....................594
Throttle Control Motor .......................................... .594
Fuel Injector ..........................................................594
Fuel Pump .............................................................594
VK45DE
SERVICE INFORMATION .. .......................
595
INDEX FOR DTC ............................................ ..595
DTC No. Index ..................................................... .595
Alphabetical Index .................................................598
PRECAUTIONS .............................................. ..603
Precaution for Supplemental Restraint System
(SRS) "AIR BAG" and "SEAT BELT PRE-TEN-
SIONER" .............................................................. .
603
Precaution for Procedure without Cowl Top Cover .603
On Board Diagnosis (OBD) System of Engine and
A/T ........................................................................
603
Precaution .............................................................604
PREPARATION ................................................607
Special Service Tool ............................................ .607
Commercial Service Tool ......................................608
ENGINE CONTROL SYSTEM ..........................609
Schematic ............................................................ .609
Multiport Fuel Injection (MFI) System ...................609
Electronic Ignition (EI) System ..............................612
Fuel Cut Control (at No Load and High Engine
Speed) ..................................................................
612
AIR CONDITIONING CUT CONTROL .............614
Input/Output Signal Chart .................................... .614
System Description ...............................................614
AUTOMATIC SPEED CONTROL DEVICE
(ASCD) ..............................................................
615
System Description .............................................. .615
Component Description ........................................616
CAN COMMUNICATION ..................................617
System Description .............................................. .617
EVAPORATIVE EMISSION SYSTEM ..............618
Description ........................................................... .618
Component Inspection ..........................................620
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EC-9
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Removal and Installation .....................................
..
622
How to Detect Fuel Vapor Leakage ......................622
ON BOARD REFUELING VAPOR RECOV-
ERY (ORVR) .....................................................
624
System Description ............................................. ..624
Diagnosis Procedure .............................................624
Component Inspection ..........................................626
POSITIVE CRANKCASE VENTILATION ........629
Description .......................................................... ..629
Component Inspection ..........................................629
IVIS (INFINITI VEHICLE IMMOBILIZER SYS-
TEM-NATS) ......................................................
631
Description .......................................................... ..631
ON BOARD DIAGNOSTIC (OBD) SYSTEM ....632
Introduction ......................................................... ..632
Two Trip Detection Logic ......................................632
Emission-related Diagnostic Information ...............633
Malfunction Indicator Lamp (MIL) ..........................649
OBD System Operation Chart ...............................652
BASIC SERVICE PROCEDURE ......................658
Basic Inspection .................................................. ..658
Idle Speed and Ignition Timing Check ..................661
Procedure After Replacing ECM ...........................662
VIN Registration ....................................................662
Accelerator Pedal Released Position Learning .....662
Throttle Valve Closed Position Learning ...............663
Idle Air Volume Learning .......................................663
Fuel Pressure Check .............................................665
TROUBLE DIAGNOSIS ...................................666
Trouble Diagnosis Introduction ........................... ..666
DTC Inspection Priority Chart ...............................670
Fail-Safe Chart ......................................................671
Symptom Matrix Chart ..........................................673
Engine Control Component Parts Location ...........677
Vacuum Hose Drawing .........................................684
Circuit Diagram .....................................................685
ECM Harness Connector Terminal Layout ...........687
ECM Terminal and Reference Value ....................687
CONSULT-III Function (ENGINE) .........................695
Generic Scan Tool (GST) Function .......................704
CONSULT-III Reference Value in Data Monitor
Mode ................................................................... ..
705
TROUBLE DIAGNOSIS - SPECIFICATION
VALUE ..............................................................
709
Description .......................................................... ..709
Testing Condition ..................................................709
Inspection Procedure ............................................709
Diagnosis Procedure .............................................710
TROUBLE DIAGNOSIS FOR INTERMITTENT
INCIDENT .........................................................
717
Description .......................................................... ..717
Diagnosis Procedure .............................................717
POWER SUPPLY AND GROUND CIRCUIT ..718
Wiring Diagram .................................................... ..718
Diagnosis Procedure .............................................719
Ground Inspection .................................................723
DTC U1000, U1001 CAN COMMUNICATION
LINE .................................................................
724
Description .............................................................724
On Board Diagnosis Logic .....................................724
DTC Confirmation Procedure ................................724
Wiring Diagram ......................................................725
Diagnosis Procedure .............................................725
DTC U1010 CAN COMMUNICATION .............726
Description .............................................................726
On Board Diagnosis Logic .....................................726
DTC Confirmation Procedure ................................726
Diagnosis Procedure .............................................726
DTC P0011, P0021 IVT CONTROL ................727
Description .............................................................727
CONSULT-III Reference Value in Data Monitor
Mode ......................................................................
728
On Board Diagnosis Logic .....................................728
DTC Confirmation Procedure ................................728
Wiring Diagram ......................................................730
Diagnosis Procedure .............................................733
Component Inspection ...........................................737
Removal and Installation .......................................738
DTC P0031, P0032, P0051, P0052 A/F SEN-
SOR 1 HEATER ..............................................
739
Description .............................................................739
CONSULT-III Reference Value in Data Monitor
Mode ......................................................................
739
On Board Diagnosis Logic .....................................739
DTC Confirmation Procedure ................................739
Wiring Diagram ......................................................740
Diagnosis Procedure .............................................743
Component Inspection ...........................................744
Removal and Installation .......................................745
DTC P0037, P0038, P0057, P0058 HO2S2
HEATER ..........................................................
746
Description .............................................................746
CONSULT-III Reference Value in Data Monitor
Mode ......................................................................
746
On Board Diagnosis Logic .....................................746
DTC Confirmation Procedure ................................746
Wiring Diagram ......................................................748
Diagnosis Procedure .............................................751
Component Inspection ...........................................752
Removal and Installation .......................................753
DTC P0075, P0081 IVT CONTROL SOLE-
NOID VALVE ...................................................
754
Component Description .........................................754
CONSULT-III Reference Value in Data Monitor
Mode ......................................................................
754
On Board Diagnosis Logic .....................................754
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EC-32
< SERVICE INFORMATION >[VQ35DE]
ENGINE CONTROL SYSTEM
*1: This sensor is not used to control the engine system under normal conditions.
*2: This signal is sent to the ECM through CAN communication line.
*3: ECM determines the start signal status by the signals of engine speed and battery voltage.
SYSTEM DESCRIPTION
The amount of fuel injected from the fuel injector is
determined by the ECM. The ECM controls the length of
time the valve remains open (injection pulse duration). T he amount of fuel injected is a program value in the
ECM memory. The program value is preset by engi ne operating conditions. These conditions are determined
by input signals (for engine speed and intake air) from both the crankshaft position sensor and the mass air
flow sensor.
VARIOUS FUEL INJECTION I NCREASE/DECREASE COMPENSATION
In addition, the amount of fuel injected is compens ated to improve engine performance under various operat-
ing conditions as listed below.
 During warm-up
 When starting the engine
 During acceleration
 Hot-engine operation
 When selector lever is changed from N to D
 High-load, high-speed operation
 During deceleration
 During high engine speed operation
MIXTURE RATIO FEEDBACK CONTROL (CLOSED LOOP CONTROL)
The mixture ratio feedback system prov ides the best air-fuel mixture ratio for driveability and emission control.
The three way catalyst 1 can then better reduce CO, HC and NOx emissions. This system uses air fuel ratio
Sensor Input Signal to ECM ECM function Actuator
Crankshaft position sensor (POS) Engine speed*
3
Piston position
Fuel injection
& mixture ratio
controlFuel injector
Camshaft position sensor (PHASE)
Mass air flow sensor Amount of intake air
Engine coolant temperature sensor Engine coolant temperature
Air fuel ratio (A/F) sensor 1 Density of oxygen in exhaust gas
Throttle position sensor Throttle position
Accelerator pedal position sensor Accelerator pedal position
Park/neutral position (PNP) switch Gear position
Knock sensor Engine knocking condition
Battery
Battery voltage*
3
Power steering pressure sensor Power steering operation
Heated oxygen sensor 2*
1Density of oxygen in exhaust gas
Air conditioner switch Air conditioner operation*
2
Wheel sensorVehicle speed*2
PBIB3020E
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ENGINE CONTROL SYSTEMEC-33
< SERVICE INFORMATION > [VQ35DE]
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(A/F) sensor 1 in the exhaust manifold to monitor
whether the engine operation is rich or lean. The ECM
adjusts the injection pulse width according to the sensor voltage signal. For more information about air fuel
ratio (A/F) sensor 1, refer to EC-220
. This maintains the mixture ratio within the range of stoichiometric (ideal
air-fuel mixture).
This stage is referred to as the closed loop control condition.
Heated oxygen sensor 2 is located downstream of the thr ee way catalyst 1. Even if the switching characteris-
tics of air fuel ratio (A/F) sensor 1 shift, the air-fuel ratio is controlled to stoichiometric by the signal from
heated oxygen sensor 2.
Open Loop Control
The open loop system condition refers to when the ECM detects any of the following conditions. Feedback
control stops in order to maintain stabilized fuel combustion.
 Deceleration and acceleration
 High-load, high-speed operation
 Malfunction of air fuel ratio (A/F) sensor 1 or its circuit
 Insufficient activation of air fuel ratio (A /F) sensor 1 at low engine coolant temperature
 High engine coolant temperature
 During warm-up
 After shifting from N to D
 When starting the engine
MIXTURE RATIO SELF-LEARNING CONTROL
The mixture ratio feedback control system monitors the mixture ratio signal transmitted from air fuel ratio (A/F)
sensor 1. This feedback signal is then sent to the ECM. The ECM controls the basic mixture ratio as close to
the theoretical mixture ratio as possible. However, the bas ic mixture ratio is not necessarily controlled as orig-
inally designed. Both manufacturing differences (i.e., mass air flow sensor hot wire) and characteristic
changes during operation (i.e., fuel injector clogging) directly affect mixture ratio.
Accordingly, the difference between the basic and theoretical mixture ratios is monitored in this system. This is
then computed in terms of “injection pulse duration” to automatically compensate for the difference between
the two ratios.
“Fuel trim” refers to the feedback compensation value co mpared against the basic injection duration. Fuel trim
includes short term fuel trim and long term fuel trim.
“Short term fuel trim” is the short-term fuel compensati on used to maintain the mixture ratio at its theoretical
value. The signal from air fuel ratio (A/F) sensor 1 i ndicates whether the mixture ratio is RICH or LEAN com-
pared to the theoretical value. The signal then triggers a r eduction in fuel volume if the mixture ratio is rich, and
an increase in fuel volume if it is lean.
“Long term fuel trim” is overall fuel compensation ca rried out long-term to compensate for continual deviation
of the short term fuel trim from the central value. Such deviation will occur due to individual engine differences,
wear over time and changes in the usage environment.
FUEL INJECTION TIMING
Two types of systems are used.
Sequential Multiport Fuel Injection System
Fuel is injected into each cylinder during each engine cycl e according to the firing order. This system is used
when the engine is running.
Simultaneous Multiport Fuel Injection System
Fuel 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 fuel 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.
SEF179U
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EC-34
< SERVICE INFORMATION >[VQ35DE]
ENGINE CONTROL SYSTEM
FUEL SHUT-OFF
Fuel to each cylinder is cut off during deceleration,
operation of the engine at excessively high speeds or oper-
ation of the vehicle at excessively high speeds.
Electronic Ignition (EI) SystemINFOID:0000000001325897
INPUT/OUTPUT SIGNAL CHART
*1: This signal is sent to the ECM through CAN communication line.
*2: ECM determines the start signal status by the signals of engine speed and battery voltage.
SYSTEM DESCRIPTION
Firing order: 1 - 2 - 3 - 4 - 5 - 6
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.
The ECM receives information such as the injection pulse width and camshaft position sensor (PHASE) sig-
nal. Computing this information, ignition si gnals are transmitted to the power transistor.
During the following conditions, the ignition timing is re vised by the ECM according to the other data stored in
the ECM.
 At starting
 During warm-up
 At idle
 At low battery voltage
 During 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.
Fuel Cut Control (at No Load and High Engine Speed)INFOID:0000000001325898
INPUT/OUTPUT SIGNAL CHART
*: This signal is sent to the ECM through CAN communication line.
SYSTEM DESCRIPTION
Sensor Input Signal to ECM ECM function Actuator
Crankshaft position sensor (POS) Engine speed*
2
Piston position
Ignition timing
controlPower transistor
Camshaft position sensor (PHASE)
Mass air flow sensor Amount of intake air
Engine coolant temperature sensor Engine coolant temperature
Throttle position sensor Throttle position
Accelerator pedal position sensor Accelerator pedal position
Knock sensor Engine knocking
Park/neutral position (PNP) switch Gear position
Battery
Battery voltage*
2
Wheel sensor
Vehicle speed*1
Sensor Input Signal to ECM ECM function Actuator
Park/neutral position (P NP) switch 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*
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EC-36
< SERVICE INFORMATION >[VQ35DE]
AIR CONDITIONING CUT CONTROL
AIR CONDITIONING CUT CONTROL
Input/Output Signal ChartINFOID:0000000001325899
*1: This signal is sent to the ECM through CAN communication line.
*2: ECM determines the start signal status by the signals of engine speed and battery voltage.
System DescriptionINFOID:0000000001325900
This system improves engine operati
on when the air conditioner is used.
Under the following conditions, the air conditioner is turned OFF.
 When the accelerator pedal is fully depressed.
 When cranking the engine.
 At high engine speeds.
 When the engine coolant temperature becomes excessively high.
 When operating power steering during low engine speed or low vehicle speed.
 When engine speed is excessively low.
 When refrigerant pressure is excessively low or high.
Sensor Input Signal to ECM ECM function Actuator
Air conditioner switch Air conditioner ON signal*
1
Air conditioner
cut controlAir conditio
ner relay
Accelerator pedal position sensor Accelerator pedal position
Throttle position sensor Throttle position
Crankshaft position sensor (POS)
Camshaft position sensor (PHASE)
Engine speed*2
Engine coolant temperature sensor Engine coolant temperature
Battery
Battery voltage*
2
Refrigerant pressure sensor Refrigerant pressure
Power steering pressure sensor Power steering operation
Wheel sensorVehicle speed*
1
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POSITIVE CRANKCASE VENTILATIONEC-51
< SERVICE INFORMATION > [VQ35DE]
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POSITIVE CRANKCASE VENTILATION
DescriptionINFOID:0000000001325911
SYSTEM DESCRIPTION
This system returns blow-by gas to the intake manifold.
The positive crankcase ventilation (PCV) valve is prov
ided to conduct crankcase blow-by gas to the intake
manifold. During partial throttle operation of the engine, the intake manifold sucks the blow-by gas through the
PCV valve. Normally, the capacity of the valve is su fficient to handle any blow-by and a small amount of venti-
lating air. The ventilating air is then drawn from the air inlet tubes into the crankcase. In this process the air
passes through the hose connecting air inlet tubes to rocker cover. Under full-throttle condition, the manifold
vacuum is insufficient to draw the blow-by flow through the valve. The flow goes through the hose connection
in the reverse direction.
On vehicles with an excessively high blow-by, the valve does not
meetthe requirement. This is because some of the flow will go
through the hoseconnection to the air inlet tubes under all condi-
tions.
Component InspectionINFOID:0000000001325912
PCV (POSITIVE CRANKCASE VENTILATION) VALVE
With engine running at idle, remove PCV valve from rocker cover. A
properly working valve makes a hissing noise as air passes through
it. A strong vacuum should be felt immediately when a finger is
placed over valve inlet.
SEC921C
PBIB1588E
PBIB1589E
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