2011 INFINITI QX56 air conditioning

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QUICK REFERENCE INDEX
AGENERAL INFORMATIONGIGeneral Information
BENGINEEMEngine Mechanical
LUEngine Lubrication System
COEngine Cooling System
ECEngine Control System
FLFuel System
EXExhaust System
STRStarting System
ACCAccelerator Control System
CHYBRIDHBCHybrid Control System
HBBHybrid Battery System
HBRHybrid Brake System
DTRANSMISSION & DRIVE-
LINECLClutch
TMTransaxle & Transmission
DLNDriveline
FAXFront Axle
RAXRear Axle
ESUSPENSIONFSUFront Suspension
RSURear Suspension
SCSSuspension Control System
WTRoad Wheels & Tires
FBRAKESBRBrake System
PBParking Brake System
BRCBrake Control System
GSTEERINGSTSteering System
STCSteering Control System
HRESTRAINTSSBSeat Belt
SBCSeat Belt Control System
SRSRS Airbag
SRCSRS Airbag Control System
IVENTILATION, HEATER &
AIR CONDITIONERVTLVentilation System
HAHeater & Air Conditioning System
HACHeater & Air Conditioning Control System
JBODY INTERIORINTInterior
IPInstrument Panel
SESeat
ADPAutomatic Drive Positioner
KBODY EXTERIOR,
DOORS, ROOF & VEHICLE
SECURITYDLKDoor & Lock
SECSecurity Control System
GWGlass & Window System
PWCPower Window Control System
RFRoof
HDHood
EXTExterior
BRMBody Repair
LDRIVER CONTROLSMIRMirrors
EXLExterior Lighting System
INLInterior Lighting System
WWWiper & Washer
DEFDefogger
HRNHorn
MELECTRICAL & POWER
CONTROLPWOPower Outlet
BCSBody Control System
LANLAN System
PCSPower Control System
CHGCharging System
PGPower Supply, Ground & Circuit Elements
NDRIVER INFORMATION &
MULTIMEDIAMWIMeter, Warning Lamp & Indicator
WCSWarning Chime System
SNSonar System
AVAudio, Visual & Navigation System
OCRUISE CONTROL &
DRIVER ASSISTANCECCSCruise Control System
DASDriver Assistance System
DMSDrive Mode System
PMAINTENANCEMAMaintenance
All rights reserved. No part
of this Service Manual may
be reproduced or stored in a
retrieval system, or transmit-
ted in any form, or by any
means, electronic, mechani-
cal, recording or otherwise,
without the prior written per-
mission of NISSAN MOTOR
CO., LTD.
Edition: May 2010
Publication No. SM1E-1Z62U0

QUICK REFERENCE CHART QX56
BRAKE PEDAL
Unit : mm (in)
FRONT DISK BRAKE
Unit : mm (in)
REAR DISK BRAKE
Unit : mm (in)
REFILL CAPACITIESELS00040
Item Standard
Brake pedal height 168.5 (6.63) – 178.5 (7.03)
Depressed brake pedal height
[Depressing 490 N (50 kg, 110 lb) while turning the engine ON] 100 (3.94) or more
Item Limit
Brake pad Wear thickness 1.5 (0.059)
Disc rotor Wear thickness 28.5 (1.122)
Thickness variation (measured at 8 positions) 0.015 (0.0006)
Runout (with it attached to the vehicle) 0.053 (0.0021)
Item Limit
Brake pad Wear thickness 2.0 (0.079)
Disc rotor Wear thickness 18.0 (0.709)
Thickness variation (measured at 8 positions) 0.015 (0.0006)
Runout (with it attached to the vehicle) 0.05 (0.0020)
UNIT
Liter US measure
Fuel tank 98.4 26 gal
Engine Coolant ( With reservoir tank ) at MAX level 14.9 15-6/8 qt
Engine oil Drain and refill
With oil filter change 6.5 6-7/8 qt
Without oil filter change 6.2 6-4/8 qt
Dry engine (Overhaul) 7.6 8 qt
Transmission 10.0 10-5/8 qt
Transfer 1.5 3-1/8 pt
Final drive Front 0.75 1-5/8 pt
Rear 1.75 3-3/4 pt
Power steering system 1.0 7/8 qt
Air conditioning system Compressor oil 0.21 7.1 fl oz
Refrigerant 1.05 kg 2.32 lb
2011

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-36
< SYSTEM DESCRIPTION >[VK56VD]
SYSTEM
DIRECT INJECTION GASOLINE SYSTEM
DIRECT INJECTION GASOLINE
SYSTEM : System DiagramINFOID:0000000006217699
DIRECT INJECTION GASOLINE SY STEM : System DescriptionINFOID:0000000006217700
INPUT/OUTPUT SIGNAL CHART
Function Reference
Fuel injection control EC-36, "
DIRECT INJECTION GASOLINE
SYSTEM : System De-
scription"
Fuel pressure control EC-39, "FUEL PRESSURE CONTROL : System Description"
Cooling fan controlEC-41, "COOLING FAN CONTROL : System Description"
Electric ignition controlEC-42, "ELECTRIC IGNITION SYSTEM : System Description"
Intake valve timing controlEC-43, "INTAKE VALVE TIMING CONTROL : System Description"
VVEL (Variable Valve Event & Lift) EC-44, "VVEL SYSTEM : System Description"
Evaporative emissionEC-45, "EVAPORATIVE EMISSION SYSTEM : System Descrip-
tion"
Air conditioning cut controlEC-47, "AIR CONDITIONING CUT CONT
ROL : System Descrip-
tion"
ASCD (Auto speed control device) EC-48, "AUTOMATIC SPEED CONTROL DEVICE (ASCD) : Sys-
tem Description"
Power generation voltage variable controlCHG-7, "POWER GENERATION VOLTAGE VARIABLE CON-
TROL SYSTEM : System Description"
JSBIA0471GB
Revision: 2010 May2011 QX56

EC-46
< SYSTEM DESCRIPTION >[VK56VD]
SYSTEM
*1: ECM determines the start signal status by the signals of engine speed and battery voltage.
*2: This signal is sent to the ECM via the CAN communication line.
SYSTEM DESCRIPTION
The evaporative emission system is used to reduce hydr
ocarbons emitted into the atmosphere from the fuel
system. This reduction of hydrocarbons is accomplis hed by activated charcoals in the EVAP canister.
The fuel vapor in the sealed fuel tank is led into t he EVAP canister which contains activated carbon and the
vapor is stored there when the engine is not oper ating or when refueling to the fuel tank.
The vapor in the EVAP canister is purged by the air through the purge line to the intake manifold when the
engine is operating. EVAP canister purge volume contro l solenoid valve is controlled by ECM. When the
engine operates, the flow rate of vapor controlled by EVAP canister purge volume control solenoid valve is
proportionally regulated as the air flow increases.
EVAP canister purge volume control solenoid valve also shuts off the vapor purge line during decelerating and
idling.
AIR CONDITIONING CUT CONTROL
Sensor Input signal to ECM ECM function Actuator
Crankshaft position sensor
Camshaft position sensor  Engine speed*
1
 Piston position
EVAP canister
purge flow controlEVAP canister purge volume
control solenoid valve
Mass air flow sensor Amount of intake air
Engine coolant temperature sensor Engine coolant temperature
Battery
Battery voltage*
1
Throttle position sensor Throttle position
Accelerator pedal position sensor Accelerator pedal position
Air fuel ratio (A/F) sensor 1 Density of oxygen in exhaust gas
(Mixture ratio
feedback signal)
Fuel tank temperature sensor Fuel temperature in fuel tank
EVAP control system pressure sensor Pressure in purge line
Combination meter Vehicle speed*
2
PBIB1631E
Revision: 2010 May2011 QX56

SYSTEMEC-47
< SYSTEM DESCRIPTION > [VK56VD]
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AIR CONDITIONING CUT CONTROL : System DiagramINFOID:0000000006217713
AIR CONDITIONING CUT CONTROL : System DescriptionINFOID:0000000006217714
INPUT/OUTPUT SIGNAL CHART
*1: This signal is sent to the ECM via the CAN communication line.
*2: ECM determines the start signal status by the signals of engine speed and battery voltage.
SYSTEM DESCRIPTION
This system improves engine operation 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.
AUTOMATIC SPEED CONTROL DEVICE (ASCD)
JMBIA1457GB
Sensor Input signal to ECM ECM function Actuator
Crankshaft position sensor
Camshaft position sensor Engine speed*
2
Air conditioner cut
controlIPDM E/R
↓
A/C relay
↓
Compressor
Engine coolant temperature sensor Engine coolant temperature
Accelerator pedal position sensor Accelerator pedal position
Battery
Battery voltage*
2
Refrigerant pressure sensor Refrigerant pressure
Power steering pressure sensor Power steering operation
A/C auto amp.A/C ON signal*
1
A/C evaporator temperature*1
Target A/C evaporator temperature*1
Blower fan ON signal
Combination meter Vehicle speed*
1
Revision: 2010 May2011 QX56

EC-148
< BASIC INSPECTION >[VK56VD]
IDLE AIR VOLUME LEARNING
IDLE AIR VOLUME LEARNING
DescriptionINFOID:0000000006217750
Idle Air Volume Learning is a function of ECM to learn
the idle air volume that keeps engine idle speed within
the specific range. It must be perfo rmed under the following conditions:
 Each time the electric throttle control actuator or ECM is replaced.
 Idle speed or ignition timing is out of the specification.
Work ProcedureINFOID:0000000006217751
1.PRECONDITIONING
Check that all of the following conditions are satisfied.
Learning will be cancelled if any of the follo wing conditions are missed for even a moment.
 Battery voltage: More than 12.9 V (At idle)
 Engine coolant temperature: 70 - 105 °C (158 - 221 °F)
 Selector lever position: P or N
 Electric load switch: OFF
(Air conditioner, headlamp, rear window defogger)
On vehicles equipped with daytime light systems, if the parking brake is applied before the engine is
started the headlamp will not illuminate.
 Steering wheel: Neutral (Straight-ahead position)
 Vehicle speed: Stopped
 Transmission: Warmed-up
- With CONSULT-III: Drive vehicle until “ATF TEMP 2” in “DATA MONITOR” mode of “A/T” system indicates
less than 0.9 V.
- Without CONSULT-III: Drive vehicle for 10 minutes.
Will CONSULT-III be used?
YES >> GO TO 2.
NO >> GO TO 3.
2.PERFORM IDLE AIR VOLUME LEARNING
WITH CONSULT-III
1. Perform Accelerator Pedal Released Position Learning. Refer to EC-146, "
Work Procedure".
2. Perform Throttle Valve Closed Position Learning. EC-147, "
Work Procedure".
3. Start engine and warm it up to normal operating temperature.
4. Select “IDLE AIR VOL LEARN” in “WORK SUPPORT” mode.
5. Touch “START” and wait 20 seconds.
Is
“CMPLT” displayed on CONSULT-III screen?
YES >> GO TO 4.
NO >> GO TO 5.
3.PERFORM IDLE AIR VOLUME LEARNING
WITHOUT CONSULT-III
NOTE:
 It is better to count the ti me accurately with a clock.
 It is impossible to switch the di agnostic mode when an accelerator pedal position sensor circuit has
a malfunction.
1. Perform Accelerator Pedal Released Position Learning. Refer to EC-146, "
Work Procedure".
2. Perform Throttle Valve Closed Position Learning. EC-147, "
Work Procedure".
3. Start engine and warm it up to normal operating temperature.
4. Turn ignition switch OFF and wait at least 10 seconds.
5. Confirm that accelerator pedal is fully releas ed, turn ignition switch ON and wait 3 seconds.
6. Repeat the following procedure quickly 5 times within 5 seconds.
- Fully depress the accelerator pedal.
- Fully release the accelerator pedal.
7. Wait 7 seconds, fully depress the accelerator pedal for approx. 20 seconds until the MIL stops blinking
and turns ON.
8. Fully release the accelerator pedal within 3 seconds after the MIL turns ON.
Revision: 2010 May2011 QX56

TROUBLE DIAGNOSIS - SPECIFICATION VALUEEC-161
< DTC/CIRCUIT DIAGNOSIS > [VK56VD]
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DTC/CIRCUIT DIAGNOSIS
TROUBLE DIAGNOSIS - SPECIFICATION VALUE
DescriptionINFOID:0000000006217760
The specification (SP) value indicates the tolerance of
the value that is displayed in “SPEC” in “DATA MONI-
TOR” mode of CONSULT-III during normal operation of the Engine Control System. When the value in “SPEC”
in “DATA MONITOR” mode is within the SP value, t he Engine Control System is confirmed OK. When the
value in “SPEC” in “DATA MONITOR” mode is NOT wit hin the SP value, the Engine Control System may have
one or more malfunctions.
The SP value is used to detect malfunctions that may affect the Engine Control System, but will not illuminate
the MIL.
The SP value will be displayed for the following items:
 B/FUEL SCHDL (The fuel injection pulse width programmed into ECM prior to any learned on board correc- tion)
 A/F ALPHA-B1/B2 (The mean value of air-fuel ratio feedback correction factor per cycle)
 MAS A/F SE-B1/B2 (The signal voltage of the mass air flow sensor)
 IDLE FUEL PRES MAX/MIN (the signal voltage of the fuel rail pressure sensor)
Component Function CheckINFOID:0000000006217761
1.PRECONDITIONING
Check that all of the following conditions are satisfied.
TESTING CONDITION
 Vehicle driven distance: More than 5,000 km (3,107 miles)
 Barometric pressure: 98.3 - 104.3 kPa (0.983 - 1.043 bar, 1.003 - 1.064 kg/cm
2, 14.25 - 15.12 psi)
 Atmospheric temperature: 20 - 30 °C (68 - 86 °F)
 Engine coolant temperature: 75 - 95 °C (167 - 203 °F)
 Transmission: Warmed-up
- After the engine is warmed up to normal operating temperat ure, drive vehicle until “ATF TEMP 2” (A/T fluid
temperature sensor signal) indicates more than 60 °C (140 °F).
 Electrical load: Not applied
- Rear window defogger switch, air conditioner switch and li ghting switch are OFF. Steering wheel is straight
ahead.
 Engine speed: Idle
 Gear position: Neutral ( or parking)
>> GO TO 2.
2.PERFORM SPEC IN DATA MONITOR MODE
WITH CONSULT-III
NOTE:
Perform “SPEC” in “DATA MONITOR” mode in maximum scale display.
1. Perform EC-139, "
Work Procedure".
2. Select “B/FUEL SCHDL”, “A/F ALPHA-B1”, “A/F ALPHA-B2”, “MAS A/F SE-B1” in “SPEC” of “DATA
MONITOR” mode with CONSULT-III.
3. Check that monitor items are within the SP value.
Is the measurement value within the SP value?
YES >> INSPECTION END
NO >> Proceed to EC-162, "
Diagnosis Procedure".
Revision: 2010 May2011 QX56