2006 INFINITI QX56 engine

COMBINATION METERSDI-21
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Revision: November 2009 2006 QX56
6. CHECK OIL PRESSURE SENSOR GROUND CIRCUIT
Check continuity between combination meter harness connector
M24 terminal 16 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-118, "
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-83, "
TROUBLE DIAGNOSIS" .
Engine Speed Signal Inspection EKS00BC8
1. CHECK ECM SELF-DIAGNOSIS
Perform ECM self-diagnosis. Refer to EC-118, "
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-83, "
TROUBLE DIAGNOSIS" .
Continuity should not exist.
WKIA2685E

DI-38
WARNING LAMPS
Revision: November 20092006 QX56
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 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 and oil pressure sensor harness connector F4
terminal 3.
OK or NG
OK >> Replace the combination meter. Refer to IP-13, "COM-
BINATION 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 and ground.
OK or NG
OK >> GO TO 4.
NG >> Replace the combination meter. Refer to IP-13, "
COM-
BINATION METER" .
Terminals
Condition Voltage (V)
(+)
(– )
Connector Terminal
M24 20 Ground When ignition switch is in ON
position. (Engine stopped)
Ye s
Engine running. (Idle speed) Yes
WKIA1833E
Continuity should exist.
WKIA1837E
Voltage : Approx. 5V
WKIA1834E

DI-40
WARNING LAMPS
Revision: November 20092006 QX56
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-66
REAR SONAR SYSTEM
Revision: November 20092006 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-82
REAR VIEW MONITOR
Revision: November 20092006 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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EC
Revision: November 2009 2006 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
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 .............. ... 45
Description .......................................................... ... 45
Component Inspection ........................................ ... 45IVIS (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) ........................ ... 63
OBD System Operation Chart ............................. ... 65
BASIC SERVICE PROCEDURE ............................ ... 71
Basic Inspection ..................................................... 71
Idle Speed and Ignition Timing Check ................. ... 76
VIN Registration ..................................................... 77
Accelerator Pedal Released Position Learning ... ... 78
Throttle Valve Closed Position Learning .............. ... 78
Idle Air Volume Learning ..................................... ... 78
Fuel Pressure Check .............................................. 80
TROUBLE DIAGNOSIS ......................................... ... 83
Trouble Diagnosis Introduction ............................ ... 83
DTC Inspection Priority Chart .............................. ... 89
Fail-safe Chart ..................................................... ... 91
Symptom Matrix Chart ......................................... ... 92
Engine Control Component Parts Location ......... ... 96
Vacuum Hose Drawing ........................................ .102
Circuit Diagram .................................................... .103
ECM Harness Connector Terminal Layout .......... .105
ECM Terminals and Reference Value .................. .105
CONSULT-II Function (ENGINE) ......................... .114
Generic Scan Tool (GST) Function ...................... .127
CONSULT-II Reference Value in Data Monitor .... .129
Major Sensor Reference Graph in Data Monitor
Mode .................................................................... .132
TROUBLE DIAGNOSIS - SPECIFICATION VALUE .134
Description ........................................................... .134
Testing Condition ................................................. .134
Inspection Procedure ........................................... .134
Diagnostic Procedure .......................................... .135
TROUBLE DIAGNOSIS FOR INTERMITTENT INCI-
DENT ...................................................................... .144

EC-5
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Component Description .......................................
. 440
On Board Diagnosis Logic .................................. . 440
DTC Confirmation Procedure .............................. . 440
Diagnostic Procedure .......................................... . 441
Removal and Installation ..................................... . 441
DTC P0500 VSS .................................................... . 442
Description .......................................................... . 442
On Board Diagnosis Logic .................................. . 442
DTC Confirmation Procedure .............................. . 442
Overall Function Check ....................................... . 442
Diagnostic Procedure .......................................... . 443
DTC P0506 ISC SYSTEM ...................................... . 444
Description .......................................................... . 444
On Board Diagnosis Logic .................................. . 444
DTC Confirmation Procedure .............................. . 444
Diagnostic Procedure .......................................... . 445
DTC P0507 ISC SYSTEM ...................................... . 446
Description .......................................................... . 446
On Board Diagnosis Logic .................................. . 446
DTC Confirmation Procedure .............................. . 446
Diagnostic Procedure .......................................... . 447
DTC P0550 PSP SENSOR .................................... . 448
Component Description ....................................... . 448
CONSULT-II Reference Value in Data Monitor Mode . 448
On Board Diagnosis Logic .................................. . 448
DTC Confirmation Procedure .............................. . 448
Wiring Diagram ................................................... . 449
Diagnostic Procedure .......................................... . 450
Component Inspection ........................................ . 452
Removal and Installation ..................................... . 452
DTC P0603 ECM POWER SUPPLY ...................... . 453
Component Description ....................................... . 453
On Board Diagnosis Logic .................................. . 453
DTC Confirmation Procedure .............................. . 453
Wiring Diagram ................................................... . 454
Diagnostic Procedure .......................................... . 455
DTC P0605 ECM ................................................... . 457
Component Description ....................................... . 457
On Board Diagnosis Logic .................................. . 457
DTC Confirmation Procedure .............................. . 457
Diagnostic Procedure .......................................... . 458
DTC P0643 SENSOR POWER SUPPLY ............... . 460
On Board Diagnosis Logic .................................. . 460
DTC Confirmation Procedure .............................. . 460
Wiring Diagram ................................................... . 461
Diagnostic Procedure .......................................... . 463
DTC P0850 PNP SWITCH ..................................... . 465
Component Description ....................................... . 465
CONSULT-II Reference Value in Data Monitor Mode . 465
On Board Diagnosis Logic .................................. . 465
DTC Confirmation Procedure .............................. . 465
Overall Function Check ....................................... . 466
Wiring Diagram ................................................... . 467
Diagnostic Procedure .......................................... . 468
DTC P1148, P1168 CLOSED LOOP CONTROL ... . 470
On Board Diagnosis Logic .................................. . 470
DTC P1211 TCS CONTROL UNIT ........................ . 471Description ...........................................................
.471
On Board Diagnosis Logic ................................... .471
DTC Confirmation Procedure .............................. .471
Diagnostic Procedure .......................................... .471
DTC P1212 TCS COMMUNICATION LINE ........... .472
Description ........................................................... .472
On Board Diagnosis Logic ................................... .472
DTC Confirmation Procedure .............................. .472
Diagnostic Procedure .......................................... .472
DTC P1217 ENGINE OVER TEMPERATURE ....... .473
Description ........................................................... .473
CONSULT-II Reference Value in Data Monitor Mode .473
On Board Diagnosis Logic ................................... .474
Overall Function Check ....................................... .474
Wiring Diagram .................................................... .476
Diagnostic Procedure .......................................... .478
Main 12 Causes of Overheating .......................... .481
Component Inspection ......................................... .482
DTC P1225 TP SENSOR ....................................... .483
Component Description ....................................... .483
On Board Diagnosis Logic ................................... .483
DTC Confirmation Procedure .............................. .483
Diagnostic Procedure .......................................... .484
Removal and Installation ..................................... .484
DTC P1226 TP SENSOR ....................................... .485
Component Description ....................................... .485
On Board Diagnosis Logic ................................... .485
DTC Confirmation Procedure .............................. .485
Diagnostic Procedure .......................................... .486
Removal and Installation ..................................... .486
DTC P1564 ICC STEERING SWITCH ................... .487
Component Description ....................................... .487
CONSULT-II Reference Value in Data Monitor Mode .487
On Board Diagnosis Logic ................................... .487
DTC Confirmation Procedure .............................. .488
Wiring Diagram .................................................... .489
Diagnostic Procedure .......................................... .490
Component Inspection ......................................... .493
DTC P1564 ASCD STEERING SWITCH ............... .494
Component Description ....................................... .494
CONSULT-II Reference Value in Data Monitor Mode .494
On Board Diagnosis Logic ................................... .494
DTC Confirmation Procedure .............................. .495
Wiring Diagram .................................................... .496
Diagnostic Procedure .......................................... .497
Component Inspection ......................................... .500
DTC P1568 ICC FUNCTION .................................. .501
On Board Diagnosis Logic ................................... .501
DTC Confirmation Procedure .............................. .501
Diagnostic Procedure .......................................... .501
DTC P1572 ICC BRAKE SWITCH ......................... .502
Component Description ....................................... .502
CONSULT-II Reference Value in Data Monitor Mode .502
On Board Diagnosis Logic ................................... .502
DTC Confirmation Procedure .............................. .503

EC-7
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Revision: November 2009 2006 QX56
Diagnostic Procedure ..........................................
. 588
Component Inspection ........................................ . 592
ASCD INDICATOR ................................................ . 593
Component Description ....................................... . 593
CONSULT-II Reference Value in Data Monitor Mode . 593
Wiring Diagram ................................................... . 594
Diagnostic Procedure .......................................... . 595
ELECTRICAL LOAD SIGNAL ............................... . 596
Description .......................................................... . 596
CONSULT-II Reference Value in Data Monitor Mode . 596
Diagnostic Procedure .......................................... . 596
FUEL INJECTOR ................................................... . 598
Component Description ....................................... . 598
CONSULT-II Reference Value in Data Monitor Mode . 598
Wiring Diagram ................................................... . 599
Diagnostic Procedure .......................................... . 600
Component Inspection ........................................ . 603
Removal and Installation ..................................... . 603
FUEL PUMP .......................................................... . 604
Description .......................................................... . 604
CONSULT-II Reference Value in Data Monitor Mode . 604
Wiring Diagram ................................................... . 605
Diagnostic Procedure .......................................... . 606
Component Inspection ........................................ . 609
Removal and Installation ..................................... . 609
ICC BRAKE SWITCH ............................................ . 610
Component Description ....................................... . 610
CONSULT-II Reference Value in Data Monitor Mode .610
Wiring Diagram .................................................... .611
Diagnostic Procedure .......................................... .612
Component Inspection ......................................... .617
IGNITION SIGNAL ................................................. .618
Component Description ....................................... .618
Wiring Diagram .................................................... .619
Diagnostic Procedure .......................................... .624
Component Inspection ......................................... .628
Removal and Installation ..................................... .629
REFRIGERANT PRESSURE SENSOR ................. .630
Component Description ....................................... .630
Wiring Diagram .................................................... .631
Diagnostic Procedure .......................................... .632
Removal and Installation ..................................... .634
MIL AND DATA LINK CONNECTOR ..................... .635
Wiring Diagram .................................................... .635
SERVICE DATA AND SPECIFICATIONS (SDS) ... .637
Fuel Pressure ...................................................... .637
Idle Speed and Ignition Timing ............................ .637
Calculated Load Value ......................................... .637
Mass Air Flow Sensor .......................................... .637
Intake Air Temperature Sensor ............................ .637
Engine Coolant Temperature Sensor .................. .637
A/F Sensor 1 Heater ............................................ .637
Heated Oxygen sensor 2 Heater ......................... .637
Crankshaft Position Sensor (POS) ...................... .637
Camshaft Position Sensor (PHASE) ................... .637
Throttle Control Motor .......................................... .637
Fuel Injector ......................................................... .638
Fuel Pump ........................................................... .638