engine INFINITI QX4 2005 Factory Service Manual

COMBINATION METERS
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Revision: October 20052005 QX56
5. CHECK OIL PRESSURE SENSOR SIGNAL CIRCUIT
1. Check continuity between combination meter harness connector M24 terminal 20 (Y) and oil pressure
sensor harness connector F4 terminal 2 (Y).
2. Check continuity between combination meter harness connector
M24 terminal 20 (Y) and ground.
OK or NG
OK >> GO TO 6.
NG >> Repair harness or connector.
6. CHECK OIL PRESSURE SENSOR GROUND CIRCUIT
Check continuity between combination meter harness connector
M24 terminal 16 (B/P) and ground.
OK or NG
OK >> Replace oil pressure sensor.
NG >> Repair harness or connector.
Water Temperature Signal Inspection EKS00BC7
1. CHECK ECM SELF-DIAGNOSIS
Perform ECM self-diagnosis. Refer to EC-130, "
SELF-DIAG RESULTS MODE" .
OK or NG
OK >> Replace the combination meter. Refer to IP-13, "Combination Meter" .
NG >> Perform "Diagnostic procedure" for displayed DTC. Refer to EC-95, "
TROUBLE DIAGNOSIS" .
Engine Speed Signal Inspection EKS00BC8
1. CHECK ECM SELF-DIAGNOSIS
Perform ECM self-diagnosis. Refer to EC-130, "
SELF-DIAG RESULTS MODE" .
OK or NG
OK >> Replace the combination meter. Refer to IP-13, "Combination Meter" .
NG >> Perform "Diagnostic procedure" for displayed DTC. Refer to EC-95, "
TROUBLE DIAGNOSIS" . Continuity should exist.
Continuity should not exist.
WKIA1836E
Continuity should not exist.
WKIA2685E

DI-26
COMPASS AND THERMOMETER
Revision: October 20052005 QX56
COMPASS AND THERMOMETERPFP:24835
System DescriptionEKS00BCE
This unit displays the following items:

Earth magnetism and heading direction of vehicle.

Outside air temperature.

Caution for frozen road surfaces.
OUTSIDE TEMPERATURE DISPLAY
Push the mode switch when the ignition switch is in the ON position. The outside temperature will be displayed
in “°F”.

Selecting the indication range
Push the mode switch to change from °F → °C → OFF → °F.

The indicated temperature on the thermometer is not readily affected by engine heat. It changes only
when one of the following conditions is present.
–The temperature detected by the ambient sensor is lower than the indicated temperature on the thermom-
eter.
–The vehicle speed is greater than 20 km/h (13 MPH).
(This is to prevent the indicated temperature from being affected by engine heat during low-speed driv-
ing.)
–The ignition switch has been turned to the OFF position for more than 2 hours. (The engine is cold.)
DIRECTION DISPLAY
Push the mode switch when the ignition switch is in the ON position. The direction will be displayed.
WKIA1817E

DI-28
COMPASS AND THERMOMETER
Revision: October 20052005 QX56
Trouble DiagnosesEKS00BCG
PRELIMINARY CHECK FOR THERMOMETER
1. COOL DOWN CHECK
1. Turn the ignition switch to the ON position.
2. Cool down the ambient sensor 2 with water or ice.
Does the indicated temperature drop?
YES >> GO TO 2.
NO >> The system is malfunctioning. Refer to DI-28, "
INSPECTION/COMPASS AND THERMOMETER"
.
2. WARM UP CHECK
1. Leave the vehicle for 10 minutes.
2. With the ignition switch in the ON position, disconnect and reconnect the ambient sensor 2 connector.
Does the indicated temperature rise?
YES >> The system is OK.
NO >> The system is malfunctioning. Refer to DI-28, "
INSPECTION/COMPASS AND THERMOMETER"
.
NOTE:
The indicated temperature on the thermometer is not readily affected by engine heat. It changes only when
one of the following conditions is present.

The temperature detected by the ambient sensor is lower than the indicated temperature on the thermom-
eter.

The vehicle speed is greater than 20 km/h (13 MPH).
(This is to prevent the indicated temperature from being affected by engine heat during low-speed driv-
ing.)

The ignition switch has been turned to the OFF position for more than 2 hours. (The engine is cold.)
INSPECTION/COMPASS AND THERMOMETER
Symptom Possible causes Repair order
No display at all 1. 10A fuse
2. Ground circuit
3. Compass and thermometer1. Check 10A fuse [No. 12, located in fuse block (J/B)].
Turn the ignition switch ON and verify that battery positive volt-
age is at terminal 2 of compass and thermometer.
2. Check ground circuit for compass and thermometer.
3. Replace compass and thermometer.
Forward direction indi-
cation slips off the mark
or incorrect.1. In manual correction mode (Bar and
display vanish)
2. Zone variation change is not done1. Drive the vehicle and turn at an angle of 90°.
2. Perform the zone variation change.
Compass reading
remains unchanged.1. Vehicle speed signal is not entered
2. Compass and thermometer1. Check harness for open or short between combination meter
terminal 29 and compass and thermometer terminal 8.
2. Replace compass and thermometer.
Displays wrong tem-
perature when ambient
temperature is between
−40°C (−40°F) and
55°C (130°F). (See
NOTE above.)1. Check operation
2. Ambient sensor circuit
3. Vehicle speed signal is not entered
4. Ambient sensor 2
5. Compass and thermometer1. Perform preliminary check shown above.
2. Check harness for open or short between ambient sensor 2 and
compass and thermometer.
3. Check harness for open or short between combination meter
terminal 29 and compass and thermometer terminal 8.
4. Replace ambient sensor 2.
5. Replace compass and thermometer.
Displays SC or OC. 1. Ambient sensor circuit
2. Ambient sensor 2
3. Compass and thermometer1. Check harness for open or short between ambient sensor 2 and
compass and thermometer.
2. Replace ambient sensor 2.
3. Replace compass and thermometer.

WARNING LAMPS
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Oil Pressure Warning Lamp Stays Off (Ignition Switch ON)EKS00BCK
1. CHECK OIL PRESSURE SENSOR SIGNAL
1. Turn ignition switch ON.
2. Check voltage between combination meter harness connector
M24 terminal 20 (Y) and ground.
OK or NG
OK >> GO TO 2.
NG >> GO TO 3.
2. CHECK OIL PRESSURE SENSOR GROUND CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect combination meter connector M24 and oil pressure
sensor connector F4.
3. Check continuity between combination meter harness connector
M24 terminal 16 (B/P) and oil pressure sensor harness connec-
tor F4 terminal 3 (B/P).
OK or NG
OK >> Replace the combination meter. Refer to IP-13, "Combi-
nation Meter" .
NG >> Repair harness or connector.
3. CHECK OIL PRESSURE SENSOR REFERENCE VOLTAGE
1. Turn ignition switch OFF.
2. Disconnect oil pressure sensor connector F4.
3. Turn ignition switch ON.
4. Check voltage between combination meter harness connector
M24 terminal 22 (GR/L) and ground.
OK or NG
OK >> GO TO 4.
NG >> Replace the combination meter. Refer to IP-13, "
Combi-
nation Meter" .
Te r m i n a l s
Condition Voltage (V) (+)
(–)
ConnectorTe r m i n a l
(Wire color)
M24 20 (Y) GroundWhen ignition switch is in ON
position. (Engine stopped)Ye s
Engine running. (Idle speed) Yes
WKIA1833E
Continuity should exist.
WKIA1837E
Voltage : Approx. 5V
WKIA1834E

WARNING LAMPS
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Oil Pressure Warning Lamp Does Not Turn Off (Oil Pressure Is Normal)EKS00BCL
NOTE:
For oil pressure inspection, refer to LU-7, "
OIL PRESSURE CHECK" .
1. CHECK ENGINE OIL PRESSURE GAUGE OPERATION
Observe operation of engine oil pressure gauge.
Does engine oil pressure gauge function properly?
YES >> Replace the combination meter. Refer to IP-13, "Combination Meter" .
NO >> Go to DI-19, "
Engine Oil Pressure Signal Inspection" .

DI-64
REAR SONAR SYSTEM
Revision: October 20052005 QX56
Pre-diagnosis InspectionEKS00BD7
SENSOR STATUS CHECK

Check that the rear sonar sensor is properly aligned (bumper is not misaligned, no deformation in sensor
mounting area.

Check that snow, mud, or other foreign objects are not adhering to the rear sonar sensor.

Check that there is no deformation, scratches, or other damage to the rear sonar sensor.

Check that water has not accumulated in the rear sonar sensor.
CAUTION:
Use water, cotton swab, or other soft material for cleaning the sensor.
1. Check that there are no obstacles within each rear sonar sensor's detection range.
2. Check that there are no nearby ultrasound sources (such as the sounds of vehicle horns, motorcycle
engines, or truck air brakes).
3. Check that the vehicle is on a level surface.
Self-diagnosis FunctionEKS00BD8
There are four modes of self-diagnosis; entering diagnostics, requesting number of fault codes, requesting
fault codes, and idling or clearing fault codes. These steps must be followed in order. Self-diagnosis can be
manually exited by turning the ignition switch OFF, or selecting reverse gear. Self-diagnosis will exit unless a
fault code request occurs before a message is repeated five times without acknowledgement.
ENTERING DIAGNOSTICS MODE
1. Turn ignition switch ON. Rear sonar system OFF switch indica-
tor lamp illuminates for three seconds and then turns off.
2. Immediately push rear sonar system OFF switch ten times
within five seconds.
3. The sonar buzzer will sound once and the rear sonar system
OFF indicator will flash once.
REQUESTING NUMBER OF FAULT CODES MODE
1. While in diagnostic mode, push rear sonar system OFF switch
once.
2. The sonar buzzer will sound once.
3. Rear sonar system OFF indicator will flash once and sonar
buzzer will sound once for each fault code detected.
4. There will be a four second pause.
5. The number of fault codes will repeat five times then pause.
NOTE:
Self-diagnosis will exit unless requesting fault codes occurs
before five repeats ends.
Detection range
Rear sonar sensors Approx. 1.8 m (5.9 ft.) maximum
LKIA0389E
LKIA0388E

DI-80
REAR VIEW MONITOR
Revision: October 20052005 QX56
Side Distance Guideline CorrectionEKS00BDL
This mode is used to modify the side distance guidelines if they are dislocated from the rear view monitor
image, because of variations of body/camera mounting conditions.
SIDE DISTANCE GUIDELINE CORRECTION PROCEDURE
1. Create a correction line to modify the screen.
Draw lines on the rearward of the vehicle passing through the
following points: 200 mm (7.87 inch) from both sides of the vehi-
cle, and

*1: 0.5 m (1.5 feet)

*2: 1 m (3 feet)

*3: 2 m (7 feet)

*4: 3 m (10 feet)
and from the rear end of the bumper
2. With the ignition switch OFF, connect “CONSULT-II” and “CON-
SULT-II CONVERTER” to the data link connector, then turn igni-
tion switch ON. Touch “REARVIEW CAMERA” on “SELECT
SYSTEM” screen.
CAUTION:
Stop engine for safety when correcting side distance guide-
line.
3. Shift the A/T select lever to R position.
4. Touch “SELCT GUIDELINE PATTERN” on “SELECT WORK
ITEM” screen.
SKIA5637E
SKIA6103E
SKIA5638E

EC-1
ENGINE CONTROL SYSTEM
B ENGINE
CONTENTS
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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-5
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ECA
Revision: October 20052005 QX56 Component Inspection ......................................... 413
Removal and Installation ...................................... 414
DTC P1146, P1166 HO2S2 ..................................... 415
Component Description ........................................ 415
CONSULT-II Reference Value in Data Monitor Mode
. 415
On Board Diagnosis Logic ................................... 415
DTC Confirmation Procedure ............................... 416
Overall Function Check ........................................ 416
Wiring Diagram .................................................... 418
Diagnostic Procedure ........................................... 421
Component Inspection ......................................... 424
Removal and Installation ...................................... 425
DTC P1147, P1167 HO2S2 ..................................... 426
Component Description ........................................ 426
CONSULT-II Reference Value in Data Monitor Mode
. 426
On Board Diagnosis Logic ................................... 426
DTC Confirmation Procedure ............................... 427
Overall Function Check ........................................ 427
Wiring Diagram .................................................... 429
Diagnostic Procedure ........................................... 432
Component Inspection ......................................... 435
Removal and Installation ...................................... 436
DTC P1148, P1168 CLOSED LOOP CONTROL .... 437
On Board Diagnosis Logic ................................... 437
DTC P1211 TCS CONTROL UNIT ......................... 438
Description ........................................................... 438
On Board Diagnosis Logic ................................... 438
DTC Confirmation Procedure ............................... 438
Diagnostic Procedure ........................................... 438
DTC P1212 TCS COMMUNICATION LINE ............ 439
Description ........................................................... 439
On Board Diagnosis Logic ................................... 439
DTC Confirmation Procedure ............................... 439
Diagnostic Procedure ........................................... 439
DTC P1217 ENGINE OVER TEMPERATURE ....... 440
Description ........................................................... 440
CONSULT-II Reference Value in Data Monitor Mode
. 440
On Board Diagnosis Logic ................................... 441
Overall Function Check ........................................ 441
Wiring Diagram .................................................... 443
Diagnostic Procedure ........................................... 445
Main 12 Causes of Overheating ........................... 448
Component Inspection ......................................... 449
DTC P1225 TP SENSOR ........................................ 450
Component Description ........................................ 450
On Board Diagnosis Logic ................................... 450
DTC Confirmation Procedure ............................... 450
Diagnostic Procedure ........................................... 451
Removal and Installation ...................................... 451
DTC P1226 TP SENSOR ........................................ 452
Component Description ........................................ 452
On Board Diagnosis Logic ................................... 452
DTC Confirmation Procedure ............................... 452
Diagnostic Procedure ........................................... 453
Removal and Installation ...................................... 453
DTC P1229 SENSOR POWER SUPPLY ................ 454On Board Diagnosis Logic ....................................454
DTC Confirmation Procedure ...............................454
Wiring Diagram .....................................................455
Diagnostic Procedure ...........................................456
DTC P1271, P1281 A/F SENSOR 1 .......................459
Component Description ........................................459
CONSULT-II Reference Value in Data Monitor Mode
.459
On Board Diagnosis Logic ....................................459
DTC Confirmation Procedure ...............................459
Wiring Diagram .....................................................461
Diagnostic Procedure ...........................................464
Removal and Installation ......................................467
DTC P1272, P1282 A/F SENSOR 1 .......................468
Component Description ........................................468
CONSULT-II Reference Value in Data Monitor Mode
.468
On Board Diagnosis Logic ....................................468
DTC Confirmation Procedure ...............................468
Wiring Diagram .....................................................470
Diagnostic Procedure ...........................................473
Removal and Installation ......................................476
DTC P1273, P1283 A/F SENSOR 1 .......................477
Component Description ........................................477
CONSULT-II Reference Value in Data Monitor Mode
.477
On Board Diagnosis Logic ....................................477
DTC Confirmation Procedure ...............................477
Wiring Diagram .....................................................479
Diagnostic Procedure ...........................................482
Removal and Installation ......................................486
DTC P1274, P1284 A/F SENSOR 1 .......................487
Component Description ........................................487
CONSULT-II Reference Value in Data Monitor Mode
.487
On Board Diagnosis Logic ....................................487
DTC Confirmation Procedure ...............................487
Wiring Diagram .....................................................489
Diagnostic Procedure ...........................................492
Removal and Installation ......................................496
DTC P1276, P1286 A/F SENSOR 1 .......................497
Component Description ........................................497
CONSULT-II Reference Value in Data Monitor Mode
.497
On Board Diagnosis Logic ....................................497
DTC Confirmation Procedure ...............................497
Overall Function Check ........................................498
Wiring Diagram .....................................................500
Diagnostic Procedure ...........................................503
Removal and Installation ......................................506
DTC P1278, P1288 A/F SENSOR 1 .......................507
Component Description ........................................507
CONSULT-II Reference Value in Data Monitor Mode
.507
On Board Diagnosis Logic ....................................507
DTC Confirmation Procedure ...............................508
Wiring Diagram .....................................................510
Diagnostic Procedure ...........................................513
Removal and Installation ......................................518

EC-7
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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