2011 INFINITI QX56 air condition

DLN-172
< UNIT DISASSEMBLY AND ASSEMBLY >[FRONT FINAL DRIVE: R180A]
DIFFERENTIAL ASSEMBLY
2. Fit a dial indicator to the drive gear back face.
3. Rotate the drive gear to measure runout.
 If the runout is outside of the repair limit, check drive gearassembly condition; foreign material may be caught between
the drive gear and differential case, or differential case or drive
gear may be deformed.
CAUTION:
Replace drive gear and drive pinion as a set.
TOOTH CONTACT
1. Remove carrier cover. Refer to DLN-168, "Disassembly".
2. Apply red lead to the drive gear. CAUTION:
Apply red lead to both the f aces of 3 to 4 gears at 4 loca-
tions evenly spaced on the drive gear.
3. Rotate the drive gear back and forth several times. Then check for correct drive pinion to drive gear tooth contact as shown.
CAUTION:
Check tooth contact on drive side and reverse side.Drive gear runout : Refer to
DLN-185, "
Drive
Gear Runout".
SPD886
SPD357
SDIA0570E
Revision: 2010 May2011 QX56

DLN-212
< UNIT DISASSEMBLY AND ASSEMBLY >[REAR FINAL DRIVE: R230]
DIFFERENTIAL ASSEMBLY
5. Install bearing caps in their correct locations and tighten bearing
cap mounting bolts.
6. Turn the carrier several times to seat the bearings.
7. Measure the turning torque of the carrier at the drive gear mounting bolts with a spring gauge [SST: — (J-8129)].
8. If the turning torque is outside the specification, use a thicker/ thinner side bearing adjusting washer to adjust. For selecting
adjusting washer, refer to the latest parts information.
CAUTION:
Select a side bearing adjust ing washer for right and left
individually.
9. Record the total amount of washer thickness required for the correct carrier side bearing preload.
DRIVE GEAR RUNOUT
1. Remove rear cover. Refer to DLN-204, "Disassembly".
2. Fit a dial indicator to the drive gear back face.
3. Rotate the drive gear to measure runout.
 If the runout is outside of the repair limit, check drive gearassembly condition; foreign material may be caught between
drive gear and differential case, or differential case or drive
gear may be deformed, etc.
CAUTION:
Replace drive gear and dri ve pinion gear as a set.
TOOTH CONTACT
Before inspection and adjustment, drain gear oil.
1. Remove rear cover. Refer to DLN-204, "
Disassembly".
SDIA1795E
Specification : 34.2 – 39.2N (3.5 – 4.0 kg,
7.7 – 8.8 lb) of pulling force
at the drive gear bolt
SPD194A
If the turning torque is less
than the specified range:Use a thicker thrust wash-
er.
If the turning torque is
greater than the specifica-
tion: Use a thinner thrust wash-
er.
SPD772
Drive gear runout : Refer to
DLN-222, "Drive
Gear Runout".
SPD886
Revision: 2010 May2011 QX56

EC-2
DIRECT INJECTION GASOLINE SYSTEM : Sys-
tem Description .......................................................
36
FUEL PRESSURE CONTROL ..................................39
FUEL PRESSURE CONTROL : System Diagram
...
39
FUEL PRESSURE CONTROL : System Descrip-
tion ..........................................................................
39
COOLING FAN CONTROL .................................... ...40
COOLING FAN CONTROL : System Diagram .......41
COOLING FAN CONTROL : System Description ...41
ELECTRIC IGNITION SYST EM ................................41
ELECTRIC IGNITION SYSTEM :
System Diagram ................................................. ...
42
ELECTRIC IGNITION SYSTEM : System De-
scription ..................................................................
42
INTAKE VALVE TIMING CONTROL ..................... ...43
INTAKE VALVE TIMING CONTROL : System Di-
agram .....................................................................
43
INTAKE VALVE TIMING CONTROL : System De-
scription ..................................................................
43
VVEL SYSTEM ....................................... ...................43
VVEL SYSTEM : System Dia gram ........................44
VVEL SYSTEM : System De scription .....................44
EVAPORATIVE EMISSION SYSTEM .................... ...45
EVAPORATIVE EMISSION SYSTEM : System
Diagram ..................................................................
45
EVAPORATIVE EMISSION SYSTEM : System
Description ..............................................................
45
AIR CONDITIONING CUT CONTROL ................... ...46
AIR CONDITIONING CUT CONTROL : System
Diagram ..................................................................
47
AIR CONDITIONING CUT CONTROL : System
Description ..............................................................
47
AUTOMATIC SPEED CONTROL DEVICE (ASCD) ...47
AUTOMATIC SPEED CONTROL DEVICE (AS-
CD) : System Diagram ............................................
48
AUTOMATIC SPEED CONTROL DEVICE (AS-
CD) : System Description .......................................
48
CAN COMMUNICATION ........................................ ...48
CAN COMMUNICATION : System Description ......48
OPERATION ................................................... ...49
AUTMATIC SPEED CONTROL DEVICE (ASCD) . ...49
AUTMATIC SPEED CONTROL DEVICE (ASCD)
: Switch Name and Function ...................................
49
ON BOARD DIAGNOSTIC (OBD) SYSTEM .....51
Diagnosis Description .......................................... ...51
GST (Generic Scan Tool) .......................................51
DIAGNOSIS SYSTEM (ECM) ............................52
DIAGNOSIS DESCRIPTION .................................. ...52
DIAGNOSIS DESCRIPTION : 1st Trip Detection
Logic and Two Trip Detection Logic ........................
52
DIAGNOSIS DESCRIPTION : DTC and Freeze
Frame Data .............................................................
52
DIAGNOSIS DESCRIPTION : Counter System ......53
DIAGNOSIS DESCRIPTION : Driving Pattern ........58
DIAGNOSIS DESCRIPTION : System Readiness
Test (SRT) Code .................................................. ...
58
DIAGNOSIS DESCRIPTION : Malfunction Indica-
tor Lamp (MIL) ..................................................... ...
60
On Board Diagnosis Function .................................60
CONSULT-III Function ............................................63
ECU DIAGNOSIS INFORMATION .............72
ECM ................................................................ ...72
Reference Value .................................................. ...72
Fail-safe ..................................................................93
DTC Inspection Priority Chart .................................96
DTC Index ...............................................................98
Test Value and Test Limit ..................................104
VVEL CONTROL MODULE .............................110
Reference Value .................................................. .110
WIRING DIAGRAM ...................................114
ENGINE CONTROL SYSTEM ........................ ..114
Wiring Diagram .................................................... .114
BASIC INSPECTION .................................135
DIAGNOSIS AND REPAIR WORKFLOW ...... ..135
Work Flow ............................................................ .135
Diagnostic Work Sheet .........................................138
BASIC INSPECTION ...................................... ..139
Work Procedure ................................................... .139
ADDITIONAL SERVICE WHEN REPLACING
ECM ..................................................................
143
Description ........................................................... .143
Work Procedure ....................................................143
ADDITIONAL SERVICE WHEN REPLACING
VVEL CONTROL MODULE .............................
144
Description ........................................................... .144
Work Procedure ....................................................144
VIN REGISTRATION ........................................145
Description ........................................................... .145
Work Procedure ....................................................145
ACCELERATOR PEDAL RELEASED POSI-
TION LEARNING ............................................ ..
146
Description ........................................................... .146
Work Procedure ....................................................146
THROTTLE VALVE CLOSED POSITION
LEARNING .......................................................
147
Description ........................................................... .147
Revision: 2010 May2011 QX56

EC-8
P2A00, P2A03 A/F SENSOR 1 .......................487
DTC Logic ............................................................ ..487
Diagnosis Procedure .............................................487
ASCD BRAKE SWITCH ................................. .490
Component Function Check ................................ ..490
Diagnosis Procedure .............................................490
Component Inspection (ASCD Brake Switch) .......491
ASCD INDICATOR ..........................................492
Component Function Check ................................ ..492
Diagnosis Procedure .............................................492
ELECTRICAL LOAD SIGNAL .........................493
Description ........................................................... ..493
Component Function Check ..................................493
Diagnosis Procedure .............................................493
ELECTRICALLY-CONTROLLED COOLING
FAN COUPLING ..............................................
495
Component Function Check ................................ ..495
Diagnosis Procedure .............................................495
FUEL INJECTOR .............................................498
Component Function Check ................................ ..498
Diagnosis Procedure .............................................498
Component Inspection ...........................................499
HIGH PRESSURE FUEL PUMP ......................501
Component Function Check ................................ ..501
Diagnosis Procedure .............................................501
Component Inspection ...........................................502
ICC BRAKE SWITCH ......................................503
Component Function Check ................................ ..503
Diagnosis Procedure .............................................503
Component Inspection (ICC Brake Switch) ...........505
IGNITION SIGNAL ...........................................506
Component Function Check ................................ ..506
Diagnosis Procedure .............................................506
Component Inspection (Ignition Coil with Power
Transistor) .............................................................
509
Component Inspection (Condenser) ......................510
INFORMATION DISPLAY (ASCD) ..................511
Component Function Check ................................ ..511
Diagnosis Procedure .............................................511
LOW PRESSURE FUEL PUMP ......................512
Component Function Check ................................ ..512
Diagnosis Procedure .............................................512
Component Inspection (Low Pressure Fuel Pump)
..
513
Component Inspection (FPCM) .............................514
MALFUNCTION INDICATOR LAMP ...............515
Component Function Check ................................ ..515
Diagnosis Procedure .............................................515
ON BOARD REFUELING VAPOR RECOV-
ERY (ORVR) .....................................................
516
Component Function Check ................................ .516
Diagnosis Procedure .............................................516
Component Inspection (EVAP Vapor Cut Valve) . .518
REFRIGERANT PRESSURE SENSOR ......... ..520
Component Function Check ................................ .520
Diagnosis Procedure .............................................520
SNOW MODE SWITCH ....................................522
Description ........................................................... .522
Component Function Check .................................522
Diagnosis Procedure .............................................522
Component Inspection ..........................................523
SYMPTOM DIAGNOSIS ...........................524
ENGINE CONTROL SYSTEM SYMPTOMS .. ..524
Symptom Table .................................................... .524
NORMAL OPERATING CONDITION ...............529
Description ........................................................... .529
PERIODIC MAINTENANCE ......................530
IDLE SPEED .......................... ...........................530
Inspection ............................................................. .530
IGNITION TIMING .............................................531
Inspection ............................................................. .531
EVAP LEAK CHECK ........................................532
Inspection ............................................................. .532
POSITIVE CRANKCASE VENTILATION .........534
Inspection ............................................................. .534
REMOVAL AND INSTALLATION .............535
ECM ................................................................ ..535
Removal and Installation ...................................... .535
VVEL CONTROL MODULE .............................536
Removal and Installation ...................................... .536
FUEL PUMP CONTROL MODULE (FPCM) ....537
Removal and Installation ...................................... .537
SERVICE DATA AND SPECIFICATIONS
(SDS) ........ .................................................
538
SERVICE DATA AND SPECIFICATIONS
(SDS) .............................................................. ..
538
Idle Speed ............................................................ .538
Ignition Timing .......................................................538
Calculated Load Value ..........................................538
Mass Air Flow Sensor ...........................................538
Revision: 2010 May2011 QX56

PRECAUTIONSEC-9
< PRECAUTION > [VK56VD]
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PRECAUTION
PRECAUTIONS
Precaution for Supplemental
Restraint System (SRS) "AIR BAG" and "SEAT BELT
PRE-TENSIONER"
INFOID:0000000006219727
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 severi ty 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 whether the front occupants are belted or unbelted.
Information necessary to service the system safely is included in the “SRS AIR BAG” and “SEAT BELT” of this
Service Manual.
WARNING:
• To avoid rendering the SRS inoper ative, which could increase the risk of personal injury or death in
the event of a collision that would result in air ba g 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 unintentional act ivation of the system. For removal of Spiral Cable and Air Bag
Module, see the “SRS AIR BAG”.
 Do not use electrical test equipm ent on any circuit related to the SRS unless instructed to in this
Service Manual. SRS wiring harnesses can be identi fied by yellow and/or orange harnesses or har-
ness connectors.
PRECAUTIONS WHEN USING POWER TOOLS (AIR OR ELECTRIC) AND HAMMERS
WARNING:
 When working near the Air Bag Diagnosis Sensor Unit or other Air Bag System sensors with the
ignition ON or engine running, DO NOT use air or electric power tools or strike near the sensor(s)
with a hammer. Heavy vibration could activate the sensor(s) and deploy the air bag(s), possibly
causing serious injury.
 When using air or electric power tools or hammers , always switch the ignition OFF, disconnect the
battery, and wait at least 3 minutes before performing any service.
Precaution for Procedur e without Cowl Top CoverINFOID:0000000006217650
When performing the procedure after removing cowl top cover, cover
the lower end of windshield with urethane, etc.
Precautions For Xenon Headlamp ServiceINFOID:0000000006217651
WARNING:
Comply with the follow ing warnings to prevent any serious accident.
 Disconnect the battery cable (neg ative terminal) or the power supply fuse before installing, remov-
ing, or touching the xenon headlamp (bulb included). The xenon headlamp contains high-voltage
generated parts.
 Never work with wet hands.
 Check the xenon headlamp ON-OFF status after assem bling it to the vehicle. Never turn the xenon
headlamp ON in other conditions. Connect th e power supply to the vehicle-side connector.
(Turning it ON outside the lamp case m ay cause fire or visual impairments.)
 Never touch the bulb glass immediately afte r turning it OFF. It is extremely hot.
PIIB3706J
Revision: 2010 May2011 QX56

COMPONENT PARTSEC-21
< SYSTEM DESCRIPTION > [VK56VD]
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Accelerator Pedal
Position SensorINFOID:0000000006217658
The accelerator pedal position (APP) sensor is installed on the
accelerator pedal assembly. The sensor detects the accelerator
position and sends a signal to the ECM.
Accelerator pedal position sensor has two sensors. These sensors
are a kind of potentiometer which transform the accelerator pedal
position into output voltage, and emit the voltage signals to the ECM.
The ECM judges the current opening angle of the accelerator pedal
from these signals and controls the throttle control motor based on
these signals.
Idle position of the accelerator pedal is determined by the ECM
receiving the signal from the accelerator pedal position sensor. The
ECM uses this signal for engine operations such as fuel cut.
Air Fuel Ratio (A/F) Sensor 1INFOID:0000000006217659
DESCRIPTION
The sensor element of the A/F sensor 1 is composed an electrode layer, 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 sens or outputs a clear, continuous signal throughout a wide range.
The exhaust gas components diffuse through the diffusion layer at the sensor cell. An electrode layer is
applied voltage, and this current relative oxygen density in lean. Also this current relative hydrocarbon density
in rich.
Therefore, the A/F sensor 1 is able to indicate air fuel ratio by this
electrode layer of current. In addition, a heater is integrated in the
sensor to ensure the required operating temperature of approxi-
mately 760 °C (1,400 °F).
A/F SENSOR 1 HEATER
A/F sensor 1 heater is integrated in the sensor.
The ECM performs ON/OFF duty control of the A/F sensor 1 heater corresponding to the engine operating
condition to keep the temperature of A/F s ensor 1 element within the specified range.
ASCD Brake Switch & Stop Lamp Switch INFOID:0000000006217660
Stop lamp switch and ASCD brake switch are installed to brake pedal bracket.
When the brake pedal is depressed, ASCD brake switch is turned OFF and stop lamp switch is turned ON.
ECM detects the state of the brake pedal by those two types of input (ON/OFF signal).
ASCD Steering SwitchINFOID:0000000006217661
ASCD steering switch has variant values of electrical resistance for each button. ECM reads voltage variation
of switch, and determines which button is operated.
ASCD IndicatorsINFOID:0000000006217662
ASCD operation status is indicated by CRUISE indicator in combination meter.
ECM transmits the ASCD status signal to the combi nation meter via CAN communication according to ASCD
operation.
PBIB1741E
JSBIA0527GB
Revision: 2010 May2011 QX56

EC-28
< SYSTEM DESCRIPTION >[VK56VD]
COMPONENT PARTS
The heated oxygen sensor 2, after three way catalyst (manifold),
monitors the oxygen level in the exhaust gas on each bank.
Even if switching characteristics of
the air fuel ratio (A/F) sensor 1
are shifted, the air fuel ratio is c ontrolled to stoichiometric, by the sig-
nal from the heated oxygen sensor 2.
This sensor is made of ceramic zirconia. The zirconia generates volt-
age from approximately 1 V in richer conditions to 0 V in leaner con-
ditions.
Under normal conditions the heated ox ygen sensor 2 is not used for
engine control operation.
HEATED OXYGEN SENSOR 2 HEATER
Heated oxygen sensor 2 heater is integrated in the sensor.
The ECM performs ON/OFF control of the heated oxy gen sensor 2 heater corresponding to the engine speed,
amount of intake air and engine coolant temperature.
High Pressure Fuel PumpINFOID:0000000006217678
The high pressure fuel pump is installed at the front of the engine bank 2 side and activated by the camshaft.
ECM controls the high pressure fuel pump control sol enoid valve built into the high pressure fuel pump and
adjusts the amount of discharge by changing the suction timing of the low pressure fuel.
Operating Description
SEF327R
Engine speed Heated oxygen sensor 2 heater
Above 3,600 rpm OFF
Below 3,600 rpm after the following conditions are met.
 Engine: After warming up
 Keeping the engine speed between 3,500 and 4,000 rpm for 1 minute and at idle for 1 minute under no load ON
JSBIA0285GB
Revision: 2010 May2011 QX56

EC-32
< SYSTEM DESCRIPTION >[VK56VD]
COMPONENT PARTS
Refrigerant Pressure Sensor
INFOID:0000000006217690
The refrigerant pressure sensor is installed at the c ondenser of the air conditioner system. The sensor uses an
electrostatic volume pressure transducer to convert refrigerant pressure to voltage. The voltage signal is sent
to ECM, and ECM controls cooling fan system.
VVEL Actuator MotorINFOID:0000000006217691
The VVEL actuator motor rotates the control shaft acco rding to the control signal from the VVEL control mod-
ule. The VVEL control module judges whether the VVEL actuator motor controls the angle properly by the
VVEL control shaft position sensor signal.
VVEL Actuator Motor RelayINFOID:0000000006217692
Power supply for the VVEL actuator motor is provided to the VVEL control module via VVEL actuator motor
relay. VVEL actuator motor relay is ON/OFF controll ed by the VVEL control module. In addition, when the
VVEL actuator motor relay cannot be controlled by the VVEL control module for some reason, it ON/OFF con-
trolled by ECM.
VVEL Control ModuleINFOID:0000000006217693
The VVEL control module consists of a microcomputer and connec-
tors for signal input and output and for power supply. The VVEL con-
trol module controls VVEL system.
VVEL Control Shaft Position SensorINFOID:0000000006217694
VVEL control shaft position sensor detects the control shaft position
angle.
A magnet is installed to the tip of the control shaft.
The magnetic field changes as the control shaft rotates. This
changes output voltage of the VVEL control shaft position sensor.
VVEL control module detects the actual position angle through the
voltage change and sends the signal to ECM.
PBIB2657E
JMBIA0879ZZ
JSBIA0466ZZ
Revision: 2010 May2011 QX56