2005 INFINITI QX4 service

CO-22Revision: October 2005
SERVICE DATA AND SPECIFICATIONS (SDS)
2005 QX56

DI-1
DRIVER INFORMATION SYSTEM
K ELECTRICAL
CONTENTS
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SECTION DI
A
B
DI
Revision: October 20052005 QX56 PRECAUTION ............................................................ 3
Precautions for Supplemental Restraint System
(SRS) “AIR BAG” and “SEAT BELT PRE-TEN-
SIONER” .................................................................. 3
Wiring Diagrams and Trouble Diagnosis .................. 3
PREPARATION ........................................................... 4
Commercial Service Tool ......................................... 4
COMBINATION METERS ........................................... 5
System Description .................................................. 5
UNIFIED METER CONTROL UNIT ...................... 5
POWER SUPPLY AND GROUND CIRCUIT ........ 6
WATER TEMPERATURE GAUGE ........................ 6
ENGINE OIL PRESSURE GAUGE ....................... 6
A/T OIL TEMPERATURE GAUGE ........................ 6
VOLTAGE GAUGE ................................................ 6
TACHOMETER ..................................................... 6
FUEL GAUGE ....................................................... 6
SPEEDOMETER ................................................... 6
CAN COMMUNICATION SYSTEM DESCRIP-
TION ...................................................................... 6
Component Parts and Harness Connector Location ..... 7
Combination Meter ................................................... 8
CHECK .................................................................. 8
Circuit Diagram ........................................................ 9
Wiring Diagram — METER — ................................ 10
Terminals and Reference Value for Combination
Meter ...................................................................... 12
Meter/Gauge Operation and Odo/Trip Meter ......... 13
SELF-DIAGNOSIS FUNCTION .......................... 13
HOW TO INITIATE COMBINATION METER
SELF- DIAGNOSIS MODE ................................. 13
COMBINATION METER SELF-DIAGNOSIS
MODE FUNCTIONS ........................................... 13
How to Proceed With Trouble Diagnosis ................ 17
Diagnosis Flow ....................................................... 17
Power Supply and Ground Circuit Inspection ........ 18
Symptom Chart ...................................................... 19
Vehicle Speed Signal Inspection ............................ 19
Engine Oil Pressure Signal Inspection ................... 19
Water Temperature Signal Inspection .................... 21Engine Speed Signal Inspection ............................. 21
Fuel Level Sensor Unit Inspection .......................... 22
FUEL LEVEL SENSOR UNIT ............................. 22
LOW-FUEL WARNING LAMP ............................. 22
Fuel Gauge Fluctuates, Indicates Wrong Value, or
Varies ...................................................................... 24
Fuel Gauge Does Not Move to Full-position ........... 24
Electrical Components Inspection .......................... 25
FUEL LEVEL SENSOR UNIT CHECK ................ 25
Removal and Installation of Combination Meter ..... 25
COMPASS AND THERMOMETER ........................... 26
System Description ................................................. 26
OUTSIDE TEMPERATURE DISPLAY ................. 26
DIRECTION DISPLAY ......................................... 26
Wiring Diagram — COMPAS — ............................. 27
Trouble Diagnoses ................................................. 28
PRELIMINARY CHECK FOR THERMOMETER ... 28
INSPECTION/COMPASS AND THERMOME-
TER ..................................................................... 28
Calibration Procedure for Compass ....................... 29
CORRECTION FUNCTIONS OF COMPASS ...... 29
INITIAL CORRECTION PROCEDURE FOR
COMPASS ........................................................... 29
WARNING LAMPS .................................................... 30
Schematic ............................................................... 30
Wiring Diagram — WARN — .................................. 31
Oil Pressure Warning Lamp Stays Off (Ignition
Switch ON) ............................................................. 37
Oil Pressure Warning Lamp Does Not Turn Off (Oil
Pressure Is Normal) ................................................ 39
A/T INDICATOR ........................................................ 40
Wiring Diagram — AT/IND — ................................. 40
A/T Indicator Does Not Illuminate ........................... 41
WARNING CHIME ..................................................... 42
Component Parts and Harness Connector Location ... 42
System Description ................................................. 42
FUNCTION .......................................................... 42
IGNITION KEY WARNING CHIME ..................... 43
LIGHT WARNING CHIME ................................... 43
SEAT BELT WARNING CHIME ........................... 43

PRECAUTION
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MA
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DI
Revision: October 20052005 QX56
PRECAUTION PFP:00011
Precautions for Supplemental Restraint System (SRS) “AIR BAG” and “SEAT
BELT PRE-TENSIONER”
EKS00BBR
The Supplemental Restraint System such as “AIR BAG” and “SEAT BELT PRE-TENSIONER”, used along
with a front seat belt, helps to reduce the risk or severity 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 and SB section of this Service Man-
ual.
WA RN ING:

To avoid rendering the SRS inoperative, which could increase the risk of personal injury or death
in the event of a collision which would result in air bag inflation, all maintenance must be per-
formed by an authorized NISSAN/INFINITI dealer.

Improper maintenance, including incorrect removal and installation of the SRS, can lead to per-
sonal injury caused by unintentional activation of the system. For removal of Spiral Cable and Air
Bag Module, see the SRS section.

Do not use electrical test equipment on any circuit related to the SRS unless instructed to in this
Service Manual. SRS wiring harnesses can be identified by yellow and/or orange harnesses or
harness connectors.
Wiring Diagrams and Trouble Diagnosis EKS00BBS
When you read wiring diagrams, refer to the following:

Refer to GI-15, "How to Read Wiring Diagrams" .

Refer to PG-4, "POWER SUPPLY ROUTING CIRCUIT" for power distribution circuit.
When you perform trouble diagnosis, refer to the following:

Refer to GI-11, "HOW TO FOLLOW TEST GROUPS IN TROUBLE DIAGNOSES" .

Refer to GI-27, "How to Perform Efficient Diagnosis for an Electrical Incident" .

DI-4
PREPARATION
Revision: October 20052005 QX56
PREPARATIONPFP:00002
Commercial Service ToolEKS00BBT
Tool nameDescription
Power toolLoosening bolts and nuts.
PBIC0191E

EC-1
ENGINE CONTROL SYSTEM
B ENGINE
CONTENTS
C
D
E
F
G
H
I
J
K
L
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SECTION EC
A
EC
Revision: October 20052005 QX56 INDEX FOR DTC ........................................................ 8
DTC No. Index ......................................................... 8
Alphabetical Index .................................................. 12
PRECAUTIONS ........................................................ 16
Precautions for Supplemental Restraint System
(SRS) “AIR BAG” and “SEAT BELT PRE-TEN-
SIONER” ................................................................ 16
On Board Diagnostic (OBD) System of Engine and
A/T .......................................................................... 16
Precaution .............................................................. 16
Wiring Diagrams and Trouble Diagnosis ................ 19
PREPARATION ......................................................... 20
Special Service Tools ............................................. 20
Commercial Service Tools ...................................... 22
ENGINE CONTROL SYSTEM .................................. 23
System Diagram ..................................................... 23
Multiport Fuel Injection (MFI) System .................... 24
Electronic Ignition (EI) System ............................... 26
Fuel Cut Control (at No Load and High Engine
Speed) .................................................................... 27
AIR CONDITIONING CUT CONTROL ..................... 28
Input/Output Signal Chart ....................................... 28
System Description ................................................ 28
AUTOMATIC SPEED CONTROL DEVICE (ASCD) ... 29
System Description ................................................ 29
Component Description .......................................... 30
CAN COMMUNICATION .......................................... 31
System Description ................................................ 31
EVAPORATIVE EMISSION SYSTEM ....................... 32
Description ............................................................. 32
Component Inspection ........................................... 35
Removal and Installation ........................................ 36
How to Detect Fuel Vapor Leakage ....................... 37
ON BOARD REFUELING VAPOR RECOVERY
(ORVR) ...................................................................... 39
System Description ................................................ 39
Diagnostic Procedure ............................................. 40
Component Inspection ........................................... 43
POSITIVE CRANKCASE VENTILATION ................. 45Description .............................................................. 45
Component Inspection ............................................ 45
IVIS (INFINITI VEHICLE IMMOBILIZER SYSTEM-
NATS) ........................................................................ 47
Description .............................................................. 47
ON BOARD DIAGNOSTIC (OBD) SYSTEM ............ 48
Introduction ............................................................. 48
Two Trip Detection Logic ........................................ 48
Emission-related Diagnostic Information ................ 49
Malfunction Indicator Lamp (MIL) ........................... 64
OBD System Operation Chart ................................ 66
BASIC SERVICE PROCEDURE ............................... 72
Basic Inspection ..................................................... 72
Idle Speed and Ignition Timing Check .................... 77
Idle Mixture Ratio Adjustment ................................. 79
VIN Registration ..................................................... 90
Accelerator Pedal Released Position Learning ...... 90
Throttle Valve Closed Position Learning ................. 90
Idle Air Volume Learning ........................................ 91
Fuel Pressure Check .............................................. 93
TROUBLE DIAGNOSIS ............................................ 95
Trouble Diagnosis Introduction ............................... 95
DTC Inspection Priority Chart ...............................101
Fail-safe Chart ......................................................103
Symptom Matrix Chart ..........................................104
Engine Control Component Parts Location ..........108
Vacuum Hose Drawing .........................................114
Circuit Diagram .....................................................115
ECM Harness Connector Terminal Layout ...........117
ECM Terminals and Reference Value ...................117
CONSULT-II Function (ENGINE) ..........................126
Generic Scan Tool (GST) Function .......................139
CONSULT-II Reference Value in Data Monitor .....141
Major Sensor Reference Graph in Data Monitor
Mode .....................................................................144
TROUBLE DIAGNOSIS - SPECIFICATION VALUE .146
Description ............................................................146
Testing Condition ..................................................146
Inspection Procedure ............................................146
Diagnostic Procedure ...........................................147

EC-7
C
D
E
F
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ECA
Revision: October 20052005 QX56 DTC P2135 TP SENSOR ........................................ 604
Component Description ........................................ 604
CONSULT-II Reference Value in Data Monitor Mode
. 604
On Board Diagnosis Logic ................................... 604
DTC Confirmation Procedure ............................... 605
Wiring Diagram .................................................... 606
Diagnostic Procedure ........................................... 607
Component Inspection ......................................... 610
Removal and Installation ...................................... 610
DTC P2138 APP SENSOR ...................................... 611
Component Description ......................................... 611
CONSULT-II Reference Value in Data Monitor Mode
.. 611
On Board Diagnosis Logic .................................... 611
DTC Confirmation Procedure ............................... 612
Wiring Diagram .................................................... 613
Diagnostic Procedure ........................................... 614
Component Inspection ......................................... 618
Removal and Installation ...................................... 618
IGNITION SIGNAL .................................................. 619
Component Description ........................................ 619
Wiring Diagram .................................................... 620
Diagnostic Procedure ........................................... 625
Component Inspection ......................................... 629
Removal and Installation ...................................... 630
INJECTOR CIRCUIT ............................................... 631
Component Description ........................................ 631
CONSULT-II Reference Value in Data Monitor Mode
. 631
Wiring Diagram .................................................... 632
Diagnostic Procedure ........................................... 633
Component Inspection ......................................... 636
Removal and Installation ...................................... 636
FUEL PUMP CIRCUIT ............................................ 637
Description ........................................................... 637
CONSULT-II Reference Value in Data Monitor Mode
. 637
Wiring Diagram .................................................... 638
Diagnostic Procedure ........................................... 639
Component Inspection ......................................... 642
Removal and Installation ...................................... 642
REFRIGERANT PRESSURE SENSOR ................. 643
Component Description ........................................ 643Wiring Diagram .....................................................644
Diagnostic Procedure ...........................................645
Removal and Installation ......................................647
ELECTRICAL LOAD SIGNAL ................................648
Description ............................................................648
CONSULT-II Reference Value in Data Monitor Mode
.648
Diagnostic Procedure ...........................................648
ICC BRAKE SWITCH .............................................649
Component Description ........................................649
CONSULT-II Reference Value in Data Monitor Mode
.649
Wiring Diagram .....................................................650
Diagnostic Procedure ...........................................651
Component Inspection ..........................................656
ASCD BRAKE SWITCH .........................................657
Component Description ........................................657
CONSULT-II Reference Value in Data Monitor Mode
.657
Wiring Diagram .....................................................658
Diagnostic Procedure ...........................................659
Component Inspection ..........................................663
ASCD INDICATOR ..................................................664
Component Description ........................................664
CONSULT-II Reference Value in Data Monitor Mode
.664
Wiring Diagram .....................................................665
Diagnostic Procedure ...........................................666
MIL AND DATA LINK CONNECTOR ......................667
Wiring Diagram .....................................................667
SERVICE DATA AND SPECIFICATIONS (SDS) ....669
Fuel Pressure .......................................................669
Idle Speed and Ignition Timing .............................669
Calculated Load Value ..........................................669
Mass Air Flow Sensor ...........................................669
Intake Air Temperature Sensor .............................669
Engine Coolant Temperature Sensor ...................669
A/F Sensor 1 Heater .............................................669
Heated Oxygen sensor 2 Heater ..........................669
Crankshaft Position Sensor (POS) .......................669
Camshaft Position Sensor (PHASE) ....................669
Throttle Control Motor ...........................................669
Injector ..................................................................670
Fuel Pump ............................................................670

EC-16Revision: October 2005
PRECAUTIONS
2005 QX56
PRECAUTIONSPFP:00001
Precautions for Supplemental Restraint System (SRS) “AIR BAG” and “SEAT
BELT PRE-TENSIONER”
UBS00KZ0
The Supplemental Restraint System such as “AIR BAG” and “SEAT BELT PRE-TENSIONER”, used along
with a front seat belt, helps to reduce the risk or severity 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 and SB section of this Service Man-
ual.
WAR NIN G:

To avoid rendering the SRS inoperative, which could increase the risk of personal injury or death
in the event of a collision which would result in air bag inflation, all maintenance must be per-
formed by an authorized NISSAN/INFINITI dealer.

Improper maintenance, including incorrect removal and installation of the SRS, can lead to per-
sonal injury caused by unintentional activation of the system. For removal of Spiral Cable and Air
Bag Module, see the SRS section.

Do not use electrical test equipment on any circuit related to the SRS unless instructed to in this
Service Manual. SRS wiring harnesses can be identified by yellow and/or orange harnesses or
harness connectors.
On Board Diagnostic (OBD) System of Engine and A/TUBS00KZ1
The ECM has an on board diagnostic system. It will light up the malfunction indicator lamp (MIL) to warn the
driver of a malfunction causing emission deterioration.
CAUTION:

Be sure to turn the ignition switch OFF and disconnect the negative battery cable before any
repair or inspection work. The open/short circuit of related switches, sensors, solenoid valves,
etc. will cause the MIL to light up.

Be sure to connect and lock the connectors securely after work. A loose (unlocked) connector will
cause the MIL to light up due to the open circuit. (Be sure the connector is free from water, grease,
dirt, bent terminals, etc.)

Certain systems and components, especially those related to OBD, may use a new style slide-
locking type harness connector. For description and how to disconnect, refer to PG-67, "
HAR-
NESS CONNECTOR" .

Be sure to route and secure the harnesses properly after work. The interference of the harness
with a bracket, etc. may cause the MIL to light up due to the short circuit.

Be sure to connect rubber tubes properly after work. A misconnected or disconnected rubber tube
may cause the MIL to light up due to the malfunction of the EVAP system or fuel injection system,
etc.

Be sure to erase the unnecessary malfunction information (repairs completed) from the ECM and
TCM (Transmission control module) before returning the vehicle to the customer.
PrecautionUBS00KZ2

Always use a 12 volt battery as power source.

Do not attempt to disconnect battery cables while engine is
running.

Before connecting or disconnecting the ECM harness con-
nector, turn ignition switch OFF and disconnect negative
battery cable. Failure to do so may damage the ECM
because battery voltage is applied to ECM even if ignition
switch is turned OFF.

Before removing parts, turn ignition switch OFF and then
disconnect battery ground cable.
SEF 2 89 H

EC-20Revision: October 2005
PREPARATION
2005 QX56
PREPARATIONPFP:00002
Special Service ToolsUBS00KZ4
The actual shapes of Kent-Moore tools may differ from those of special service tools illustrated here.
Tool number
(Kent-Moore No.)
Tool nameDescription
EG17650301
(J-33984-A)
Radiator cap tester
adapterAdapting radiator cap tester to radiator cap and ra-
diator filler neck
a: 28 (1.10) dia.
b: 31.4 (1.236) dia.
c: 41.3 (1.626) dia.
Unit: mm (in)
KV10117100
(J-36471-A)
Heated oxygen sensor
wrenchLoosening or tightening heated oxygen sensors
with 22 mm (0.87 in) hexagon nut
KV10114400
(J-38365)
Heated oxygen sensor
wrenchLoosening or tightening heated oxygen sensors
a: 22 mm (0.87 in)
(J-44626)
Air fuel ratio (A/F) sen-
sor wrenchLoosening or tightening air fuel ratio (A/F) sensor 1
(J-44321)
Fuel pressure gauge
kitChecking fuel pressure
(J-44321-6)
Fuel pressure adapterConnecting fuel pressure gauge to quick connec-
tor type fuel lines.
(J-45488)
Quick connector re-
leaseRemove fuel tube quick connectors in engine
room.
S-NT564
S-NT379
S-NT636
LEM054
LEC642
LBIA0376E
PBIC0198E