2004 INFINITI QX56 Engine Control System

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PRECAUTIONS
Revision: August 20072004 QX56
(i.e. Flexible Fuel Vehicle - FFV models). Using a fuel other than that specified could adversely affect
the emission control devices and systems, and could also affect the warranty coverage validity.
Precautions for Multiport Fuel Injection System or Engine Control SystemEAS0014B

Before connecting or disconnecting any harness connector for
the multiport fuel injection system or ECM:
Turn ignition switch to “OFF” position.
Disconnect negative battery terminal.
Otherwise, there may be damage to ECM.

Before disconnecting pressurized fuel line from fuel pump to
injectors, be sure to release fuel pressure.

Be careful not to jar components such as ECM and mass air
flow sensor.
Precautions for HosesEAS0014C
HOSE REMOVAL AND INSTALLATION

To prevent damage to rubber hose, do not pry off rubber hose
with tapered tool or screwdriver.

To reinstall the rubber hose securely, make sure of hose inser-
tion length and clamp orientation. (If tube is equipped with hose
stopper, insert rubber hose into tube until it butts up against
hose stopper.)
HOSE CLAMPING

If old rubber hose is re-used, install hose clamp in its original
position (at the indentation where the old clamp was). If there is
a trace of tube bulging left on the old rubber hose, align rubber
hose at that position.

Discard old clamps; replace with new ones.
SGI787
SM A01 9D
SM A02 0D
SM A02 1D

CONSULT-II CHECKING SYSTEM
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CONSULT-II CHECKING SYSTEMPFP:00000
DescriptionEAS001SK

CONSULT-II is a hand-held type tester. When it is connected with a diagnostic connector equipped on the
vehicle side, it will communicate with the control unit equipped in the vehicle and then enable various
kinds of diagnostic tests.

Refer to "CONSULT-II Operator's Manual" for more information.
Function and System ApplicationEAS001SL
x: Applicable.
*1: IVIS (NATS) [INFINITI Vehicle Immobilizer System (Nissan Anti-Theft System)].
*2: This system is shown with IVIS (NATS) using program card AEN04A-1 or later.Diagnostic test
modeFunction
ENGINE
A/T
ALL MODE AWD/4WD
ICC
ABS
AIR BAG
IPDM E/R
BCM
AUTO DRIVE POS.
REARVIEW CAMERA
AIR LEVELIZER
IVIS (NATS)
*1
IVIS (NATS BCM OR S/ENT)
*1
Work supportThis mode enables a technician to adjust some
devices faster and more accurately by following the
indications on CONSULT-II.x - xxx - - xxxx - -
Self-diagnosticSelf-diagnostic can be performed quickly. -----x-------
Self-diagnos-
tic resultsSelf-diagnostic results can be read and erased
quickly.xxxxx - xxx - xxx
Trouble diag-
nostic recordCurrent self-diagnostic results and all trouble diagnos-
tic records previously stored can be read.----- x-------
Data monitor Input/Output data in the ECM can be read. xxxxx - x - xxx - -
Data monitor
(spec)Data monitor specification can be read. x------------
CAN diagno-
sis support
monitorThe communication condition of CAN communication
line can be read.xxxxx - xxx - - - -
Active testDiagnostic Test Mode in which CONSULT-II drives
some actuators apart from the ECMs and also shifts
some parameters in a specified range.x- - xx- x- xxx- -
Function testThis mode can show results of self-diagnosis of ECU
with either “OK” or “NG”. For engines, more practical
tests regarding sensors/switches and/or actuators are
available.xx - - xx - -- - -- -
DTC & SRT
confirmationThe results of SRT (System Readiness Test) and the
self-diagnosis status/result can be confirmed.x------------
DTC work sup-
portThe operating condition to confirm Diagnosis Trouble
Codes can be selected.xx-----------
ECM/ECU part
numberECM/ECU part number can be read. xxxxx - -xx xx - -
ECU discrimi-
nated No.Classification number of a replacement ECU can be
read to prevent an incorrect ECU from being installed.-----x-------
Configuration ECM checks its own NATS communication interface. -------x-----
PIN read
*2This mode shows the BCM-specific 5-digit code. ------------x
Control unit
initialization
*2All registered ignition key IDs in NATS components
can be initialized and new IDs can be registered.-----------x-

CONSULT-II CHECKING SYSTEM
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2. If necessary, turn on the ignition switch.
3. Touch “START (NISSAN BASED VHCL)” or System Shortcut
key (eg: ENGINE) on the screen.
CONSULT-II Data Link Connector (DLC) CircuitEAS001SM
INSPECTION PROCEDURE
If the CONSULT-II cannot diagnose the system properly, check the following items:
NOTE:
The preceding schematic is an example and may not be a true representation of the vehicle. The actual DDL1
circuits (CAN lines) from DLC pins 6 and 14 as well as the DDL2 circuit (K-line) from DLC pin 7 may be con-
nected to more than one system. A short in a DDL circuit connected to a control unit in one system may affect
CONSULT-II access to other systems.
BCIA0029E
LAIA0028E
Symptom Check item
CONSULT-II cannot access
any system.

CONSULT-II DLC power supply circuit (Terminal 8) and ground circuit (Terminal 4). For detailed cir-
cuit, refer to LAN-5, "
CAN Communication Unit" .

CONSULT-II DLC cable and CONSULT-II CONVERTER.
CONSULT-II cannot access
individual system. (Other sys-
tems can be accessed.)

CONSULT-II program card (Check the appropriate CONSULT-II program card for the system.
Refer to GI-38, "
Checking Equipment" .

Power supply and ground circuit for the control unit of the system (For detailed circuit, refer to wir-
ing diagram for each system.)

Open or short circuit between the system and CONSULT-II DLC (For detailed circuit, refer to wiring
diagram for each system.)

Open or short circuit in CAN or K communication line. Refer to LAN-3, "Precautions When Using
CONSULT-II" .

GI-50
TERMINOLOGY
Revision: August 20072004 QX56
TERMINOLOGYPFP:00011
SAE J1930 Terminology List EAS00157
All emission related terms used in this publication in accordance with SAE J1930 are listed. Accordingly, new
terms, new acronyms/abbreviations and old terms are listed in the following chart.
NEW TERMNEW ACRONYM /
ABBREVIATIONOLD TERM
Air cleaner ACL Air cleaner
Barometric pressure BARO ***
Barometric pressure sensor-BCDD BAROS-BCDD BCDD
Camshaft position CMP ***
Camshaft position sensor CMPS Crank angle sensor
Canister *** Canister
Carburetor CARB Carburetor
Charge air cooler CAC Intercooler
Closed loop CL Closed loop
Closed throttle position switch CTP switch Idle switch
Clutch pedal position switch CPP switch Clutch switch
Continuous fuel injection system CFI system ***
Continuous trap oxidizer system CTOX system ***
Crankshaft position CKP ***
Crankshaft position sensor CKPS ***
Data link connector DLC ***
Data link connector for CONSULT-II DLC for CONSULT-II Diagnostic connector for CONSULT-II
Diagnostic test mode DTM Diagnostic mode
Diagnostic test mode selector DTM selector Diagnostic mode selector
Diagnostic test mode I DTM I Mode I
Diagnostic test mode II DTM II Mode II
Diagnostic trouble code DTC Malfunction code
Direct fuel injection system DFI system ***
Distributor ignition system DI system Ignition timing control
Early fuel evaporation-mixture heater EFE-mixture heater Mixture heater
Early fuel evaporation system EFE system Mixture heater control
Electrically erasable programmable read
only memoryEEPROM ***
Electronic ignition system EI system Ignition timing control
Engine control EC ***
Engine control module ECM ECCS control unit
Engine coolant temperature ECT Engine temperature
Engine coolant temperature sensor ECTS Engine temperature sensor
Engine modification EM ***
Engine speed RPM Engine speed
Erasable programmable read only memory EPROM ***
Evaporative emission canister EVAP canister Canister
Evaporative emission system EVAP system Canister control solenoid valve
Exhaust gas recirculation valve EGR valve EGR valve

TERMINOLOGY
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Exhaust gas recirculation control-BPT
valveEGRC-BPT valve BPT valve
Exhaust gas recirculation control-solenoid
valveEGRC-solenoid valve EGR control solenoid valve
Exhaust gas recirculation temperature sen-
sor
EGRT sensor Exhaust gas temperature sensor
EGR temperature sensor
Flash electrically erasable programmable
read only memoryFEEPROM ***
Flash erasable programmable read only
memoryFEPROM ***
Flexible fuel sensor FFS ***
Flexible fuel system FF system ***
Fuel pressure regulator *** Pressure regulator
Fuel pressure regulator control solenoid
valve*** PRVR control solenoid valve
Fuel trim FT ***
Heated Oxygen sensor HO2S Exhaust gas sensor
Idle air control system IAC system Idle speed control
Idle air control valve-air regulator IACV-air regulator Air regulator
Idle air control valve-auxiliary air control
valveIACV-AAC valve Auxiliary air control (AAC) valve
Idle air control valve-FICD solenoid valve IACV-FICD solenoid valve FICD solenoid valve
Idle air control valve-idle up control sole-
noid valveIACV-idle up control solenoid valve Idle up control solenoid valve
Idle speed control-FI pot ISC-FI pot FI pot
Idle speed control system ISC system ***
Ignition control IC ***
Ignition control module ICM ***
Indirect fuel injection system IFI system ***
Intake air IA Air
Intake air temperature sensor IAT sensor Air temperature sensor
Knock *** Detonation
Knock sensor KS Detonation sensor
Malfunction indicator lamp MIL Check engine light
Manifold absolute pressure MAP ***
Manifold absolute pressure sensor MAPS ***
Manifold differential pressure MDP ***
Manifold differential pressure sensor MDPS ***
Manifold surface temperature MST ***
Manifold surface temperature sensor MSTS ***
Manifold vacuum zone MVZ ***
Manifold vacuum zone sensor MVZS ***
Mass air flow sensor MAFS Air flow meter
Mixture control solenoid valve MC solenoid valve Air-fuel ratio control solenoid valve
Multiport fuel injection System MFI system Fuel injection controlNEW TERMNEW ACRONYM /
ABBREVIATIONOLD TERM

REAR WINDOW DEFOGGER
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System DescriptionEIS002VN
The rear window defogger system is controlled by BCM (body control module) and IPDM E/R (intelligent
power distribution module engine room).
The rear window defogger operates only for approximately 15 minutes.
Power is supplied at all times

through 15A fuses (No. 43, 46, and 47, located in the IPDM E/R)

to rear window defogger relay terminals 3 and 6 (located in the IPDM E/R)

through 50A fusible link (letter f , located in the fuse and fusible link box)

to BCM terminal 70.
With the ignition switch turned to ON or START position,
Power is supplied

through ignition switch

to rear window defogger relay (located in the IPDM E/R)

through 10A fuse (No. 59, located in the fuse and relay box)

to BCM terminal 38

through 10A fuse [No. 8, located in the fuse block (J/B)]

to front air control terminal 14.
Ground is supplied

to BCM terminal 67

to front air control terminal 1

through body grounds M57, M61 and M79

to IPDM E/R terminals 38 and 59

through body grounds E9, E15 and E24.
When front air control (rear window defogger switch) is turned to ON,
Ground is supplied

to BCM terminal 9

through front air control terminal 11

through front air control terminal 1

through body grounds M57, M61 and M79.
Then rear window defogger switch is illuminated.
Then BCM recognizes that rear window defogger switch is turned to ON.
Then it sends rear window defogger switch signals to IPDM E/R and display control unit via DATA LINE (CAN-
H, CAN-L).
When display control unit receives rear window defogger switch signals, and displays on the screen.
When IPDM E/R receives rear window defogger switch signals,
Ground is supplied

to rear window defogger relay (located in the IPDM E/R)

through IPDM E/R terminal 38

through IPDM E/R terminal 59

through body grounds E9, E15 and E24.
Then rear window defogger relay is energized.
With power and ground supplied, rear window defogger filaments heat and defog the rear window.
When rear window defogger relay is turned to ON,
Power is supplied

through heated mirror relay (located in the IPDM E/R)

through IPDM E/R terminal 23

to door mirror defogger (LH and RH) terminal 10.
Door mirror defogger (LH and RH) is grounded through body grounds M57, M61 and M79.
With power and ground supplied, rear window defogger filaments heat and defog the rear window and door
mirror defogger filaments heat and defog the mirror.

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IDX
ALPHABETICAL INDEX
Brake lines and cables inspection ..................... MA-27
Brake master cylinder ....................................... BR-15
Brake switch .................................................... EC-551
BRK/SW - Wiring diagram ............................... EC-552
Bulb specifications ........................................... LT-170
Bumper, front ...................................................... EI-13
Bumper, rear ....................................................... EI-15
C
Cabin air filter .................................................... MA-20
Camshaft ........................................................... EM-43
Camshaft inspection .......................................... EM-47
Camshaft position sensor (PHASE) ................ EC-261
CAN - Wiring diagram EC-136, LAN-18, LAN-52, LAN-
92, LAN-128
CAN (Controller Area Network) .. WT-9, BRC-10, LAN-
16, LAN-50, LAN-90, LAN-126
CAN communication . EC-31, EC-135, AT-103, WT-9,
BRC-10
, LAN-16, LAN-50, LAN-90, LAN-126
Canister-See EVAP canister ........................... EC-636
Center case (Transfer) ..................................... TF-113
CHARGE - Wiring diagram ............................... SC-18
Charging system ............................................... SC-17
Chassis and body maintenance ........................ MA-20
Chassis and body maintenanceSchedule 1 ........ MA-7
Chassis and body maintenanceSchedule 2 ........ MA-9
CHIME - Wiring diagram ..................................... DI-46
Circuit breaker ................................................... PG-67
Clock ................................................................... DI-70
CLOCK - Wiring diagram .................................... DI-70
Closed loop control ........................................... EC-27
Closed loop control (Bank 1) ........................... EC-407
Closed loop control (Bank 2) ........................... EC-407
Clutch drum (Transfer) ..................................... TF-116
Clutch force release limit adjustment ................. TF-42
Clutch pressure switch (Transfer) ...................... TF-95
Coil spring (front) ............................................. FSU-10
Collision diagnosis .......................................... SRS-60
Combination lamp, front, removal and installation . LT-
33
Combination lamp, rear, removal and installation .. LT-
122
Combination meter ................................................ DI-5
Combination switch ............................................ LT-97
COMBSW - Wiring diagram ............................... LT-97
COMM - Wiring diagram ................................... AV-87
COMPAS - Wiring diagram ................................. DI-27
Compass ............................................................. DI-26
Component Location (auto A/C) ...................... ATC-37
Compressor clutch removal and installation . ATC-167
Compressor mounting ................................... ATC-166
Compressor precaution ................................... ATC-11
Compressor special service tool ..................... ATC-14
Condenser ..................................................... ATC-173
Connecting rod .................................................. EM-91
Connecting rod bearing clearance .................... EM-91
Connecting rod bushing clearance .................... EM-91
Console box - See Instrument panel ................... IP-10
Console box lamp ............................................. LT-152
CONSULT for all-mode 4WD ............................. TF-31
CONSULT for VDC ......................................... BRC-28
CONSULT-II for engine ................................... EC-103
Control units (terminal arrangement) ................. PG-71
Control valve (A/T) ............................................. AT-37
Control valve (Transfer) .................................... TF-119
Controller Area Network (CAN) . WT-9, BRC-10, LAN-
16, LAN-50, LAN-90, LAN-126
Converter housing installation ............ AT-257, AT-260
COOL/F - Wiring diagram ................................ EC-413
Coolant mixture ratio ......................................... MA-11
Coolant replacement ......................................... MA-12
Cooling circuit (engine) ........................................ CO-6
Cooling fan ........................................................ CO-13
Cooling fan control ........................................... EC-410
Cooling fan motor ............................................ EC-419
Cooling unit (A/C evaporator) ....... ATC-144, ATC-175
Corrosion protection ......................................... BL-167
Crankcase ventilation system - See Positive crankcase
ventilation ........................................................ EC-645
Crankshaft ......................................................... EM-74
Crankshaft position sensor (POS) ................... EC-255
Crash zone sensor .......................................... SRS-55
Cylinder block .................................................... EM-73
Cylinder block boring ......................................... EM-94
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D/LOCK - Wiring diagram ................................... BL-20
Data link connector .......................................... EC-105
Daytime light system .......................................... LT-34
Daytime running light - See Daytime light system .. LT-
34
DEF - Wiring diagram ....................................... GW-82
Diagnosis sensor unit ...................................... SRS-58
Diagnostic trouble code (DTC) .......................... EC-53
Diagnostic trouble code (DTC) for OBD system .. EC-8
Diagnostic trouble code (DTC) inspection priority chart
EC-76
Differential carrier assembly ............................ RFD-11
Differential carrier disassembly ....................... RFD-13
Differential gear oil replacement ........................ MA-25
Dimensions ......................................................... GI-49
Direct clutch solenoid valve ................ AT-157, AT-160
Display and amp.assembly .............................. ATC-60
Display Control Unit ......................................... AV-158
Dome light - See Interior lamp .......................... LT-129
Door glass .......................................... GW-69, GW-72
Door lock .......................................................... BL-132
Door mirror lamp ............................................... LT-129
Door trim .............................................................. EI-31
Door, front ........................................... BL-129, GW-69
Door, rear ........................................... BL-129, GW-72
Drive belt ........................................................... EM-12
Drive chain (Transfer) ....................................... TF-115
Drive pinion diff. inspection .............................. RFD-12
Drive pinion height ........................................... RFD-17
Drive shaft (rear) ................................................ RAX-7

IDX-4
ALPHABETICAL INDEX
Driver air bag .................................................. SRS-45
DTC work support ............................................ EC-113
DTRL - Wiring diagram ....................................... LT-37
Duct and grilles .............................................. ATC-157
DVD Player ........................................................ AV-59
E
ECM input/output signal ..................................... EC-96
ECM power supply ............................. EC-128, EC-361
ECM relay ........................................................ EC-128
ECM/PW - Wiring diagram ............................... EC-362
ECTS - Wiring diagram .................................... EC-167
Electric sunroof .................................................. RF-10
Electric throttle control actuator ......... EC-365, EC-367
Electrical load signal circuit .............................. EC-612
Electrical units location ...................................... PG-64
Electronic ignition (EI) system ........................... EC-28
Engine control circuit diagram ........................... EC-94
Engine control component parts location ........... EC-88
Engine control module (ECM) .......................... EC-351
Engine control system diagram and chart ......... EC-23
Engine coolant .................................................... CO-8
Engine coolant temperature sensor (ECTS) ... EC-165,
EC-178
Engine fail-safe system ...................................... EC-77
Engine oil ............................................................. LU-7
Engine oil filter replacement ............................. MA-16
Engine oil precautions .......................................... GI-7
Engine oil replacement ..................................... MA-16
Engine removal ................................................. EM-70
Engine room cover ............................................ EM-11
Engine serial number .......................................... GI-48
ETC1 - Wiring diagram .................................... EC-368
ETC2 - Wiring diagram .................................... EC-375
ETC3 - Wiring diagram .................................... EC-379
EVAP canister .................................................. EC-636
EVAP canister purge volume control solenoid valve ....
EC-285
, EC-496
EVAP canister vent control valve ....... EC-292, EC-504
EVAP control system (small leak) diagnosis .. EC-276,
EC-316
, EC-324
EVAP control system pressure sensor .... EC-299, EC-
302, EC-308
EVAP control system purge flow monitoring diagnosis
EC-271
EVAP vapor lines inspection ............................. MA-19
Evaporative emission (EVAP) system ............. EC-633
Evaporator ..................................................... ATC-175
Exhaust manifold .............................................. EM-19
Exhaust system ................................................... EX-3
Exhaust system inspection .................................. EX-3
Expansion valve ............................................. ATC-177
F
F/FOG - Wiring diagram ..................................... LT-71
F/PUMP - Wiring diagram ................................ EC-602
Final drive pre-inspection .................. FFD-15, RFD-12
Final drive removal and installation ... FFD-12, RFD-10
Flow charts .......................................................... GI-27
Fluid temperature sensor (A/T) ........................ AT-131
Fluids ................................................................ MA-10
Fluorescent leak detector .............................. ATC-178
Fog lamp, front ................................................... LT-69
Foot lamp ......................................................... LT-129
Freeze frame data ............................... EC-54, EC-107
Front brake solenoid valve ................. AT-151, AT-154
Front bumper ...................................................... EI-13
Front case (Transfer) ....................................... TF-125
Front combination lamp removal and installation LT-33
Front door ............................. BL-129, BL-132, GW-69
Front Door Trim ................................................... EI-31
Front drive shaft (Transfer) .............................. TF-115
Front fog lamp .................................................... LT-69
Front passenger air bag .................................. SRS-50
Front seat ........................................................... SE-96
Front seat belt ...................................................... SB-3
Front seat belt pre-tensioner ............... SRS-3, SRS-57
Front washer ...................................................... WW-4
Front wiper ......................................................... WW-4
FTTS - Wiring diagram ...................... EC-227, EC-232
Fuel cut control (at no load high engine speed) EC-30
Fuel filter replacement ......................................... FL-5
Fuel gauge ............................................................ DI-5
Fuel injection system (Bank 1) .......... EC-208, EC-217
Fuel injection system (Bank 2) .......... EC-208, EC-217
Fuel injector and fuel tube ................................. EM-29
Fuel level sensor ................. EC-334, EC-336, EC-338
Fuel line inspection .............................................. FL-3
Fuel precautions ................................................... GI-5
Fuel pressure check .......................................... EC-46
Fuel pressure release ....................................... EC-46
Fuel pump ....................................................... EC-601
Fuel pump and gauge .......................................... FL-5
Fuel system .......................................................... FL-3
Fuel tank .............................................................. FL-9
Fuel tank temperature sensor ........... EC-225, EC-231
Fuel tank vacuum relief valve ......................... EC-636
FUELB1 - Wiring diagram ................. EC-210, EC-219
FUELB2 - Wiring diagram ................. EC-211, EC-220
Fuse ...................................................... PG-67, PG-77
Fuse and fusible link box .................................. PG-77
Fuse block ......................................................... PG-76
Fusible link ............................................ PG-67, PG-77
G
Garage jack and safety stand ............................. GI-40
Gauges ................................................................. DI-5
Generator .......................................................... SC-17
Generic scan tool (GST) ................................. EC-116
Glass ...................................... GW-11, GW-69, GW-72
Glove box lamp ................................... LT-152, LT-153
GPS antenna ..................................................... AV-62
Grease .............................................................. MA-10
Ground distribution ............................................ PG-30