check engine INFINITI QX56 2004 Factory Service Manual

REAR SONAR SYSTEM
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Revision: August 20072004 QX56
Pre-diagnosis InspectionEKS007EX
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 FunctionEKS007EY
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

EC-1
ENGINE CONTROL SYSTEM
B ENGINE
CONTENTS
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SECTION EC
A
EC
Revision: August 20072004 QX56 INDEX FOR DTC ........................................................ 8
Alphabetical Index .................................................... 8
DTC No. 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
Vacuum Hose Drawing ........................................... 24
System Chart ......................................................... 25
Multiport Fuel Injection (MFI) System .................... 26
Electronic Ignition (EI) System ............................... 28
Nissan Torque Demand (NTD) Control System ..... 29
Air Conditioning Cut Control ................................... 30
Fuel Cut Control (at No Load and High Engine
Speed) .................................................................... 30
CAN communication .............................................. 31
BASIC SERVICE PROCEDURE .............................. 32
Idle Speed and Ignition Timing Check .................... 32
Idle Speed/Ignition Timing/Idle Mixture Ratio
Adjustment ............................................................. 33
Accelerator Pedal Released Position Learning ...... 44
Throttle Valve Closed Position Learning ................ 44
Idle Air Volume Learning ........................................ 44
Fuel Pressure Check .............................................. 46
ON BOARD DIAGNOSTIC (OBD) SYSTEM ............ 49
Introduction ............................................................ 49
Two Trip Detection Logic ........................................ 49
Emission-related Diagnostic Information ................ 50
IVIS (Infiniti Vehicle Immobilizer System — NATS) ... 63
Malfunction Indicator Lamp (MIL) ........................... 63
OBD System Operation Chart ................................ 66TROUBLE DIAGNOSIS ............................................ 71
Trouble Diagnosis Introduction ............................... 71
DTC Inspection Priority Chart ................................. 76
Fail-safe Chart ........................................................ 77
Basic Inspection ..................................................... 79
Symptom Matrix Chart ............................................ 84
Engine Control Component Parts Location ............ 88
Circuit Diagram ....................................................... 94
ECM Harness Connector Terminal Layout ............. 96
ECM Terminals and Reference Value ..................... 96
CONSULT-II Function ...........................................103
Generic Scan Tool (GST) Function .......................116
CONSULT-II Reference Value in Data Monitor .....118
Major Sensor Reference Graph in Data Monitor
Mode .....................................................................121
TROUBLE DIAGNOSIS - SPECIFICATION VALUE .123
Description ............................................................123
Testing Condition ..................................................123
Inspection Procedure ............................................123
Diagnostic Procedure ...........................................124
TROUBLE DIAGNOSIS FOR INTERMITTENT INCI-
DENT .......................................................................127
Description ............................................................127
Diagnostic Procedure ...........................................127
POWER SUPPLY AND GROUND CIRCUIT ...........128
Wiring Diagram .....................................................128
Diagnostic Procedure ...........................................129
Ground Inspection ................................................133
DTC U1000, U1001 CAN COMMUNICATION LINE .135
Description ............................................................135
On Board Diagnosis Logic ....................................135
DTC Confirmation Procedure ...............................135
Wiring Diagram .....................................................136
Diagnostic Procedure ...........................................137
DTC P0037, P0038, P0057, P0058 HO2S2 HEATER .138
Description ............................................................138
CONSULT-II Reference Value in Data Monitor Mode
.138
On Board Diagnosis Logic ....................................138
DTC Confirmation Procedure ...............................139

EC-5
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ECA
Revision: August 20072004 QX56 Overall Function Check ........................................ 396
Wiring Diagram .................................................... 398
Diagnostic Procedure ........................................... 401
Component Inspection ......................................... 404
Removal and Installation ...................................... 406
DTC P1148, P1168 CLOSED LOOP CONTROL .... 407
On Board Diagnosis Logic ................................... 407
DTC P1211 TCS CONTROL UNIT ......................... 408
Description ........................................................... 408
On Board Diagnosis Logic ................................... 408
DTC Confirmation Procedure ............................... 408
Diagnostic Procedure ........................................... 408
DTC P1212 TCS COMMUNICATION LINE ............ 409
Description ........................................................... 409
On Board Diagnosis Logic ................................... 409
DTC Confirmation Procedure ............................... 409
Diagnostic Procedure ........................................... 409
DTC P1217 ENGINE OVER TEMPERATURE ....... 410
Description ........................................................... 410
CONSULT-II Reference Value in Data Monitor Mode
. 410
On Board Diagnosis Logic .................................... 411
Overall Function Check ......................................... 411
Wiring Diagram .................................................... 413
Diagnostic Procedure ........................................... 415
Main 12 Causes of Overheating ........................... 418
Component Inspection ......................................... 419
DTC P1225 TP SENSOR ........................................ 420
Component Description ........................................ 420
On Board Diagnosis Logic ................................... 420
DTC Confirmation Procedure ............................... 420
Diagnostic Procedure ........................................... 421
Removal and Installation ...................................... 421
DTC P1226 TP SENSOR ........................................ 422
Component Description ........................................ 422
On Board Diagnosis Logic ................................... 422
DTC Confirmation Procedure ............................... 422
Diagnostic Procedure ........................................... 423
Removal and Installation ...................................... 423
DTC P1229 SENSOR POWER SUPPLY ................ 424
On Board Diagnosis Logic ................................... 424
DTC Confirmation Procedure ............................... 424
Wiring Diagram .................................................... 425
Diagnostic Procedure ........................................... 426
DTC P1271, P1281 A/F SENSOR 1 ....................... 429
Component Description ........................................ 429
CONSULT-II Reference Value in Data Monitor Mode
. 429
On Board Diagnosis Logic ................................... 429
DTC Confirmation Procedure ............................... 429
Wiring Diagram .................................................... 431
Diagnostic Procedure ........................................... 434
Removal and Installation ...................................... 436
DTC P1272, P1282 A/F SENSOR 1 ....................... 437
Component Description ........................................ 437
CONSULT-II Reference Value in Data Monitor Mode
. 437
On Board Diagnosis Logic ................................... 437
DTC Confirmation Procedure ............................... 437Wiring Diagram .....................................................439
Diagnostic Procedure ...........................................442
Removal and Installation ......................................444
DTC P1273, P1283 A/F SENSOR 1 .......................445
Component Description ........................................445
CONSULT-II Reference Value in Data Monitor Mode
.445
On Board Diagnosis Logic ....................................445
DTC Confirmation Procedure ...............................445
Wiring Diagram .....................................................447
Diagnostic Procedure ...........................................450
Removal and Installation ......................................453
DTC P1274, P1284 A/F SENSOR 1 .......................454
Component Description ........................................454
CONSULT-II Reference Value in Data Monitor Mode
.454
On Board Diagnosis Logic ....................................454
DTC Confirmation Procedure ...............................454
Wiring Diagram .....................................................456
Diagnostic Procedure ...........................................459
Removal and Installation ......................................462
DTC P1276, P1286 A/F SENSOR 1 .......................463
Component Description ........................................463
CONSULT-II Reference Value in Data Monitor Mode
.463
On Board Diagnosis Logic ....................................463
DTC Confirmation Procedure ...............................463
Overall Function Check ........................................464
Wiring Diagram .....................................................466
Diagnostic Procedure ...........................................469
Removal and Installation ......................................471
DTC P1278, P1288 A/F SENSOR 1 .......................472
Component Description ........................................472
CONSULT-II Reference Value in Data Monitor Mode
.472
On Board Diagnosis Logic ....................................472
DTC Confirmation Procedure ...............................473
Wiring Diagram .....................................................475
Diagnostic Procedure ...........................................478
Removal and Installation ......................................483
DTC P1279, P1289 A/F SENSOR 1 .......................484
Component Description ........................................484
CONSULT-II Reference Value in Data Monitor Mode
.484
On Board Diagnosis Logic ....................................484
DTC Confirmation Procedure ...............................485
Wiring Diagram .....................................................487
Diagnostic Procedure ...........................................490
Removal and Installation ......................................495
DTC P1444 EVAP CANISTER PURGE VOLUME
CONTROL SOLENOID VALVE ...............................496
Description ............................................................496
CONSULT-II Reference Value in Data Monitor Mode
.496
On Board Diagnosis Logic ....................................497
DTC Confirmation Procedure ...............................497
Wiring Diagram .....................................................498
Diagnostic Procedure ...........................................500

EC-20Revision: August 2007
PREPARATION
2004 QX56
PREPARATIONPFP:00002
Special Service ToolsUBS00GZ9
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

PREPARATION
EC-21
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EC
Revision: August 20072004 QX56
KV109E0010
(J-46209)
Break-out boxMeasuring the ECM signals with a circuit tester
KV109E0080
(J-45819)
Y-cable adapterMeasuring the ECM signals with a circuit tester
(J-23688)
Engine coolant refrac-
tometerChecking concentration of ethylene glycol in en-
gine coolant Tool number
(Kent-Moore No.)
Tool nameDescription
S-NT825
S-NT826
W BIA0539E

EC-22Revision: August 2007
PREPARATION
2004 QX56
Commercial Service ToolsUBS00GZA
Tool name
(Kent-Moore No.)Description
Leak detector
i.e.: (J-41416)Locating the EVAP leak
EVAP service port
adapter
i.e.: (J-41413-OBD)Applying positive pressure through EVAP service
port
Fuel filler cap adapter
i.e.: (MLR-8382)Checking fuel tank vacuum relief valve opening
pressure
Socket wrench Removing and installing engine coolant tempera-
ture sensor
Oxygen sensor thread
cleaner
i.e.: (J-43897-18)
(J-43897-12)Reconditioning the exhaust system threads before
installing a new oxygen sensor. Use with anti-
seize lubricant shown below.
a: 18 mm diameter with pitch 1.5 mm for Zirco-
nia Oxygen Sensor
b: 12 mm diameter with pitch 1.25 mm for Tita-
nia Oxygen Sensor
Anti-seize lubricant
i.e.: (Permatex
TM
133AR or equivalent
meeting MIL specifica-
tion MIL-A-907)Lubricating oxygen sensor thread cleaning tool
when reconditioning exhaust system threads.
S-NT703
S-NT704
S-NT815
S-NT705
AEM488
S-NT779

BASIC SERVICE PROCEDURE
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Revision: August 20072004 QX56
3. Check ignition timing.
Idle Speed/Ignition Timing/Idle Mixture Ratio AdjustmentUBS00GZL
PREPARATION
1. Make sure that the following parts are in good order.

Battery

Ignition system

Engine oil and coolant levels

Fuses

ECM harness connector

Vacuum hoses

Air intake system
(Oil filler cap, oil level gauge, etc.)

Fuel pressure

Engine compression

Throttle valve

Evaporative emission system
2. On air conditioner equipped models, checks should be carried out while the air conditioner is OFF.
3. On automatic transmission equipped models, when checking idle rpm, ignition timing and mixture ratio,
checks should be carried out while shift lever is in N position.
4. When measuring CO percentage, insert probe more than 40 cm (15.7 in) into tail pipe.
5. Turn off headlamp, heater blower, rear window defogger.
6. Keep front wheels pointed straight ahead.
SEF 0 11V
BBIA0379E

BASIC SERVICE PROCEDURE
EC-35
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EC
Revision: August 20072004 QX56
INSPECTION PROCEDURE
1. INSPECTION START
1. Check service records for any recent repairs that may indicate a related malfunction, or a current need for
scheduled maintenance.
2. Open engine hood and check the following:
–Harness connectors for improper connections
–Wiring harness for improper connections, pinches and cut
–Vacuum hoses for splits, kinks and improper connections
–Hoses and ducts for leaks
–Air cleaner clogging
–Gasket
3. Confirm that electrical or mechanical loads are not applied.
–Headlamp switch is OFF.
–Air conditioner switch is OFF.
–Rear window defogger switch is OFF.
–Steering wheel is in the straight-ahead position, etc.
4. Start engine and warm it up until engine coolant temperature
indicator points the middle of gauge.
Ensure engine stays below 1,000 rpm.
5. Run engine at about 2,000 rpm for about 2 minutes under no
load.
6. Make sure that no DTC is displayed with CONSULT-II or GST.
OK or NG
OK >> GO TO 3.
NG >> GO TO 2.
2. REPAIR OR REPLACE
Repair or replace components as necessary according to corresponding Diagnostic Procedure.
>> GO TO 3.
SEF 9 83 U
SEF 9 76 U
SEF 9 77 U

EC-36Revision: August 2007
BASIC SERVICE PROCEDURE
2004 QX56
3. CHECK TARGET IDLE SPEED
With CONSULT-II
1. Run engine at about 2,000 rpm for about 2 minutes under no load.
2. Rev engine (2,000 to 3,000 rpm) two or three times under no
load, then run engine at idle speed for about 1 minute.
3. Read idle speed in “DATA MONITOR” mode with CONSULT-II.
Without CONSULT-II
1. Run engine at about 2,000 rpm for about 2 minutes under no load.
2. Rev engine (2,000 to 3,000 rpm) two or three times under no load, then run engine at idle speed for about
1 minute.
3. Check idle speed.
OK or NG
OK >> GO TO 10.
NG >> GO TO 4.
4. PERFORM ACCELERATOR PEDAL RELEASED POSITION LEARNING
1. Stop engine.
2. Perform EC-44, "
Accelerator Pedal Released Position Learning" .
>> GO TO 5.
5. PERFORM THROTTLE VALVE CLOSED POSITION LEARNING
Perform EC-44, "
Throttle Valve Closed Position Learning" .
>> GO TO 6.
SEF 9 78 U
650 ± 50 rpm (in P or N position)
SEF 0 58 Y
650 ± 50 rpm (in P or N position)

BASIC SERVICE PROCEDURE
EC-37
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Revision: August 20072004 QX56
6. PERFORM IDLE AIR VOLUME LEARNING
Perform EC-44, "
Idle Air Volume Learning" .
Is Idle Air Volume Learning carried out successfully?
Ye s o r N o
Yes >> GO TO 7.
No >> 1. Follow the instruction of Idle Air Volume Learning.
2. GO TO 4.
7. CHECK TARGET IDLE SPEED AGAIN
With CONSULT-II
1. Start engine and warm it up to normal operating temperature.
2. Read idle speed in “DATA MONITOR” mode with CONSULT-II.
Without CONSULT-II
1. Start engine and warm it up to normal operating temperature.
2. Check idle speed.
OK or NG
OK >> GO TO 10.
NG >> GO TO 8.
8. DETECT MALFUNCTIONING PART
Check the following.

Check camshaft position sensor (PHASE) and circuit. Refer to EC-261 .

Check crankshaft position sensor (POS) and circuit. Refer to EC-255 .
OK or NG
OK >> GO TO 9.
NG >> 1. Repair or replace.
2. GO TO 4.
9. CHECK ECM FUNCTION
1. Substitute another known-good ECM to check ECM function. (ECM may be the cause of an incident, but
this is a rare case.)
2. Perform initialization of IVIS (NATS) system and registration of all IVIS (NATS) ignition key IDs. Refer to
IBL-140, "
ECM Re-communicating Function" .
>> GO TO 4. 650 ± 50 rpm (in P or N position)
650 ± 50 rpm (in P or N position)