2007 INFINITI QX56 check engine

WARNING LAMPS
DI-33
< SERVICE INFORMATION >
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No malfunction detected>>GO TO 2.
Malfunction detected>>GO TO PG-18, "
CONSULT-II Function (IPDM E/R)".
2.CHECK IPDM E/R INPUT SIGNAL
Select "IPDM E/R" on CONSULT-II. Operate ignition switch with "OIL
P SW" of "DATA MONITOR" and check operation status.
OK or NG
OK >> Replace combination meter. Refer to IP-10, "Removal
and Installation".
NG >> GO TO 3.
3.CHECK OIL PRESSURE SWITCH CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect IPDM E/R connector E122 and oil pressure switch
connector F4.
3. Check continuity between IPDM E/R harness connector E122
(A) terminal 42 and oil pressure switch harness connector F4 (B)
terminal 1.
OK or NG
OK >> GO TO 4.
NG >> Repair harness or connector.
4.CHECK OIL PRESSURE SWITCH
Check oil pressure switch. Refer to DI-21, "
Electrical Component Inspection".
OK or NG
OK >> Replace IPDM E/R. Refer to PG-28, "Removal and Installation of IPDM E/R".
NG >> Replace oil pressure switch.
Oil Pressure Warning Lamp Does Not Turn Off (Oil Pressure Is Normal)INFOID:0000000003533507
NOTE:
For oil pressure inspection, refer to DI-21, "
Electrical Component Inspection".
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-10, "Removal and Installation".
NO >> GO TO DI-17, "
Engine Oil Pressure Signal Inspection". When ignition switch is in ON
position (Engine stopped): OIL P SW CLOSE
When engine running : OIL P SW OPEN
LKIA0403E
Continuity should exist.
WKIA5607E

REAR SONAR SYSTEM
DI-51
< SERVICE INFORMATION >
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How to Proceed with Trouble DiagnosisINFOID:0000000003533529
1. Confirm the symptom or customer complaint.
2. Understand operation description and function description. Refer to DI-46, "
System Description".
3. Perform pre-diagnosis inspection. Refer to DI-51, "
Pre-diagnosis Inspection".
4. Perform self-diagnosis. Refer to DI-51, "
Self-Diagnosis Function".
5. Perform the preliminary check. Refer to DI-53, "
Preliminary Check".
6. Check symptom and repair or replace the cause of malfunction. Refer to DI-54, "
Symptom Chart".
7. Does the rear sonar system operate properly? If so, go to 8. If not, go to 3.
8. Clear fault codes. Refer to DI-51, "
Self-Diagnosis Function".
9. Inspection End.
Pre-diagnosis InspectionINFOID:0000000003533530
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 FunctionINFOID:0000000003533531
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
Detection range
Rear sonar sensors Approx. 1.8 m (5.9 ft.) maximum
LKIA0389E

EC-1
ENGINE
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SECTION EC
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CONTENTS
ENGINE CONTROL SYSTEM
SERVICE INFORMATION ............................9
INDEX FOR DTC .................................................9
DTC No. Index ..........................................................9
Alphabetical Index ...................................................12
PRECAUTIONS ..................................................17
Precaution for Supplemental Restraint System
(SRS) "AIR BAG" and "SEAT BELT PRE-TEN-
SIONER" .................................................................
17
On Board Diagnosis (OBD) System of Engine and
A/T ...........................................................................
17
Precaution ...............................................................17
PREPARATION ..................................................21
Special Service Tool ...............................................21
Commercial Service Tool ........................................22
ENGINE CONTROL SYSTEM ............................24
Schematic ...............................................................24
Multiport Fuel Injection (MFI) System .....................24
Electronic Ignition (EI) System ................................27
Fuel Cut Control (at No Load and High Engine
Speed) .....................................................................
27
AIR CONDITIONING CUT CONTROL ...............29
Input/Output Signal Chart ........................................29
System Description .................................................29
AUTOMATIC SPEED CONTROL DEVICE
(ASCD) ...............................................................
30
System Description .................................................30
Component Description ...........................................31
CAN COMMUNICATION ....................................32
System Description .................................................32
EVAPORATIVE EMISSION SYSTEM ................33
Description ..............................................................33
Component Inspection ............................................35
Removal and Installation .........................................37
How to Detect Fuel Vapor Leakage ........................37
ON BOARD REFUELING VAPOR RECOV-
ERY (ORVR) ......................................................
40
System Description ..................................................40
Diagnosis Procedure ...............................................40
Component Inspection .............................................42
POSITIVE CRANKCASE VENTILATION .........45
Description ...............................................................45
Component Inspection .............................................45
IVIS (INFINITI VEHICLE IMMOBILIZER SYS-
TEM-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 .....................75
Procedure After Replacing ECM .............................77
VIN Registration ......................................................77
Accelerator Pedal Released Position Learning .......77
Throttle Valve Closed Position Learning .................77
Idle Air Volume Learning .........................................78
Fuel Pressure Check ...............................................80
TROUBLE DIAGNOSIS ....................................82
Trouble Diagnosis Introduction ................................82
DTC Inspection Priority Chart ..................................87
Fail-Safe Chart ........................................................88
Symptom Matrix Chart .............................................90
Engine Control Component Parts Location .............94
Vacuum Hose Drawing ..........................................100
Circuit Diagram ......................................................101
ECM Harness Connector Terminal Layout ............103
ECM Terminal and Reference Value .....................103

EC-2
CONSULT-II Function (ENGINE) ..........................111
Generic Scan Tool (GST) Function .......................122
CONSULT-II Reference Value in Data Monitor
Mode ......................................................................
124
Major Sensor Reference Graph in Data Monitor
Mode ......................................................................
127
TROUBLE DIAGNOSIS - SPECIFICATION
VALUE .............................................................
129
Description .............................................................129
Testing Condition ...................................................129
Inspection Procedure .............................................129
Diagnosis Procedure .............................................130
TROUBLE DIAGNOSIS FOR INTERMITTENT
INCIDENT ........................................................
138
Description .............................................................138
Diagnosis Procedure .............................................138
POWER SUPPLY AND GROUND CIRCUIT ...139
Wiring Diagram ......................................................139
Diagnosis Procedure .............................................140
Ground Inspection .................................................143
DTC U1000, U1001 CAN COMMUNICATION
LINE .................................................................
145
Description .............................................................145
On Board Diagnosis Logic .....................................145
DTC Confirmation Procedure ................................145
Wiring Diagram ......................................................146
Diagnosis Procedure .............................................146
DTC U1010 CAN COMMUNICATION .............147
Description .............................................................147
On Board Diagnosis Logic .....................................147
DTC Confirmation Procedure ................................147
Diagnosis Procedure .............................................147
DTC P0011, P0021 IVT CONTROL .................149
Description .............................................................149
CONSULT-II Reference Value in Data Monitor
Mode ......................................................................
150
On Board Diagnosis Logic .....................................150
DTC Confirmation Procedure ................................150
Wiring Diagram ......................................................152
Diagnosis Procedure .............................................155
Component Inspection ...........................................159
Removal and Installation .......................................160
DTC P0031, P0032, P0051, P0052 A/F SEN-
SOR 1 HEATER ...............................................
163
Description .............................................................163
CONSULT-II Reference Value in Data Monitor
Mode ......................................................................
163
On Board Diagnosis Logic .....................................163
DTC Confirmation Procedure ................................163
Wiring Diagram ......................................................164
Diagnosis Procedure .............................................167
Component Inspection ...........................................168
Removal and Installation .......................................169
DTC P0037, P0038, P0057, P0058 HO2S2
HEATER ...........................................................
170
Description ............................................................170
CONSULT-II Reference Value in Data Monitor
Mode .....................................................................
170
On Board Diagnosis Logic ....................................170
DTC Confirmation Procedure ................................170
Wiring Diagram .....................................................172
Diagnosis Procedure .............................................175
Component Inspection ..........................................176
Removal and Installation .......................................177
DTC P0075, P0081 IVT CONTROL SOLE-
NOID VALVE ....................................................
178
Component Description ........................................178
CONSULT-II Reference Value in Data Monitor
Mode .....................................................................
178
On Board Diagnosis Logic ....................................178
DTC Confirmation Procedure ................................178
Wiring Diagram .....................................................179
Diagnosis Procedure .............................................182
Component Inspection ..........................................183
Removal and Installation .......................................184
DTC P0101 MAF SENSOR ..............................186
Component Description ........................................186
CONSULT-II Reference Value in Data Monitor
Mode .....................................................................
186
On Board Diagnosis Logic ....................................186
DTC Confirmation Procedure ................................186
Overall Function Check .........................................188
Wiring Diagram .....................................................189
Diagnosis Procedure .............................................190
Component Inspection ..........................................192
Removal and Installation .......................................193
DTC P0102, P0103 MAF SENSOR ..................194
Component Description ........................................194
CONSULT-II Reference Value in Data Monitor
Mode .....................................................................
194
On Board Diagnosis Logic ....................................194
DTC Confirmation Procedure ................................194
Wiring Diagram .....................................................196
Diagnosis Procedure .............................................197
Component Inspection ..........................................199
Removal and Installation .......................................200
DTC P0112, P0113 IAT SENSOR ....................201
Component Description ........................................201
On Board Diagnosis Logic ....................................201
DTC Confirmation Procedure ................................201
Wiring Diagram .....................................................202
Diagnosis Procedure .............................................202
Component Inspection ..........................................204
Removal and Installation .......................................204
DTC P0117, P0118 ECT SENSOR ...................205
Component Description ........................................205
On Board Diagnosis Logic ....................................205
DTC Confirmation Procedure ................................206

EC-6
DTC P0605 ECM ..............................................444
Component Description .........................................444
On Board Diagnosis Logic .....................................444
DTC Confirmation Procedure ................................444
Diagnosis Procedure .............................................445
DTC P0643 SENSOR POWER SUPPLY ........447
On Board Diagnosis Logic .....................................447
DTC Confirmation Procedure ................................447
Wiring Diagram ......................................................448
Diagnosis Procedure .............................................449
DTC P0850 PNP SWITCH ...............................452
Component Description .........................................452
CONSULT-II Reference Value in Data Monitor
Mode ......................................................................
452
On Board Diagnosis Logic .....................................452
DTC Confirmation Procedure ................................452
Overall Function Check .........................................453
Wiring Diagram ......................................................454
Diagnosis Procedure .............................................455
DTC P1140, P1145 IVT CONTROL POSITION
SENSOR ..........................................................
457
Component Description .........................................457
CONSULT-II Reference Value in Data Monitor
Mode ......................................................................
457
On Board Diagnosis Logic .....................................457
DTC Confirmation Procedure ................................457
Wiring Diagram ......................................................458
Diagnosis Procedure .............................................461
Component Inspection ...........................................463
Removal and Installation .......................................464
DTC P1148, P1168 CLOSED LOOP CON-
TROL ................................................................
466
On Board Diagnosis Logic .....................................466
DTC P1211 TCS CONTROL UNIT ..................467
Description .............................................................467
On Board Diagnosis Logic .....................................467
DTC Confirmation Procedure ................................467
Diagnosis Procedure .............................................467
DTC P1212 TCS COMMUNICATION LINE .....468
Description .............................................................468
On Board Diagnosis Logic .....................................468
DTC Confirmation Procedure ................................468
Diagnosis Procedure .............................................468
DTC P1217 ENGINE OVER TEMPERATURE .469
Description .............................................................469
CONSULT-II Reference Value in Data Monitor
Mode ......................................................................
469
On Board Diagnosis Logic .....................................470
Overall Function Check .........................................470
Wiring Diagram ......................................................472
Diagnosis Procedure .............................................473
Main 13 Causes of Overheating ............................476
Component Inspection ...........................................476
DTC P1225 TP SENSOR ..................................477
Component Description ........................................477
On Board Diagnosis Logic ....................................477
DTC Confirmation Procedure ................................477
Diagnosis Procedure .............................................477
Removal and Installation .......................................478
DTC P1226 TP SENSOR ..................................479
Component Description ........................................479
On Board Diagnosis Logic ....................................479
DTC Confirmation Procedure ................................479
Diagnosis Procedure .............................................479
Removal and Installation .......................................480
DTC P1421 COLD START CONTROL ............481
Description ............................................................481
On Board Diagnosis Logic ....................................481
DTC Confirmation Procedure ................................481
Diagnosis Procedure .............................................481
DTC P1550 BATTERY CURRENT SENSOR ...483
Component Description ........................................483
CONSULT-II Reference Value in Data Monitor
Mode .....................................................................
483
On Board Diagnosis Logic ....................................483
DTC Confirmation Procedure ................................483
Wiring Diagram .....................................................485
Diagnosis Procedure .............................................486
Component Inspection ..........................................488
DTC P1551, P1552 BATTERY CURRENT
SENSOR ...........................................................
489
Component Description ........................................489
CONSULT-II Reference Value in Data Monitor
Mode .....................................................................
489
On Board Diagnosis Logic ....................................489
DTC Confirmation Procedure ................................489
Wiring Diagram .....................................................491
Diagnosis Procedure .............................................492
Component Inspection ..........................................494
DTC P1553 BATTERY CURRENT SENSOR ...495
Component Description ........................................495
CONSULT-II Reference Value in Data Monitor
Mode .....................................................................
495
On Board Diagnosis Logic ....................................495
DTC Confirmation Procedure ................................495
Wiring Diagram .....................................................497
Diagnosis Procedure .............................................498
Component Inspection ..........................................500
DTC P1554 BATTERY CURRENT SENSOR ...501
Component Description ........................................501
CONSULT-II Reference Value in Data Monitor
Mode .....................................................................
501
On Board Diagnosis Logic ....................................501
Overall Function Check .........................................501
Wiring Diagram .....................................................503
Diagnosis Procedure .............................................504
Component Inspection ..........................................506

EC-22
< SERVICE INFORMATION >
PREPARATION
Commercial Service Tool
INFOID:0000000003531584
(J-45488)
Quick connector re-
leaseRemove fuel tube quick connectors in engine
room.
(J-23688)
Engine coolant refrac-
tometerChecking concentration of ethylene glycol in en-
gine coolant Tool number
(Kent-Moore No.)
Tool nameDescription
PBIC0198E
WBIA0539E
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
S-NT703
S-NT704
S-NT815
S-NT705

EC-40
< SERVICE INFORMATION >
ON BOARD REFUELING VAPOR RECOVERY (ORVR)
ON BOARD REFUELING VAPOR RECOVERY (ORVR)
System DescriptionINFOID:0000000003531598
From the beginning of refueling, the air and vapor inside the fuel tank go through refueling EVAP vapor cut
valve and EVAP/ORVR line to the EVAP canister. The vapor is absorbed by the EVAP canister and the air is
released to the atmosphere.
When the refueling has reached the full level of the fuel tank, the refueling EVAP vapor cut valve is closed and
refueling is stopped because of auto shut-off. The vapor which was absorbed by the EVAP canister is purged
during driving.
WARNING:
When conducting inspections below, be sure to observe the following:
• Put a “CAUTION: FLAMMABLE” sign in workshop.
• Do not smoke while servicing fuel system. Keep open flames and sparks away from work area.
• Be sure to furnish the workshop with a CO
2 fire extinguisher.
CAUTION:
• Before removing fuel line parts, carry out the following procedures:
- Put drained fuel in an explosion-proof container and put lid on securely.
- Release fuel pressure from fuel line. Refer to EC-80, "
Fuel Pressure Check" .
- Disconnect battery ground cable.
• Always replace O-ring when the fuel gauge retainer is removed.
• Do not kink or twist hose and tube when they are installed.
• Do not tighten hose and clamps excessively to avoid damaging hoses.
• After installation, run engine and check for fuel leaks at connection.
• Do not attempt to top off the fuel tank after the fuel pump nozzle shuts off automatically.
Continued refueling may cause fuel overflow, resulting in fuel spray and possibly a fire.
Diagnosis ProcedureINFOID:0000000003531599
SYMPTOM: FUEL ODOR FROM EVAP CANISTER IS STRONG.
1.CHECK EVAP CANISTER
1. Remove EVAP canister with EVAP canister vent control valve and EVAP control system pressure sensor
attached.
2. Weigh the EVAP canister with EVAP canister vent control valve and EVAP control system pressure sensor
attached.
The weight should be less than 2.5 kg (5.5 lb).
OK or NG
OK >> GO TO 2.
NG >> GO TO 3.
2.CHECK IF EVAP CANISTER SATURATED WITH WATER
PBIB1068E

EC-48
< SERVICE INFORMATION >
ON BOARD DIAGNOSTIC (OBD) SYSTEM
ON BOARD DIAGNOSTIC (OBD) SYSTEM
IntroductionINFOID:0000000003531604
The ECM has an on board diagnostic system, which detects malfunctions related to engine sensors or actua-
tors. The ECM also records various emission-related diagnostic information including:
The above information can be checked using procedures listed in the table below.
×: Applicable —: Not applicable
*: When DTC and 1st trip DTC simultaneously appear on the display, they cannot be clearly distinguished from each other.
The malfunction indicator lamp (MIL) on the instrument panel lights up when the same malfunction is detected
in two consecutive trips (Two trip detection logic), or when the ECM enters fail-safe mode. (Refer to EC-88,
"Fail-Safe Chart".)
Two Trip Detection LogicINFOID:0000000003531605
When a malfunction is detected for the first time, 1st trip DTC and 1st trip Freeze Frame data are stored in the
ECM memory. The MIL will not light up at this stage. <1st trip>
If the same malfunction is detected again during the next drive, the DTC and Freeze Frame data are stored in
the ECM memory, and the MIL lights up. The MIL lights up at the same time when the DTC is stored. <2nd
trip> The “trip” in the “Two Trip Detection Logic” means a driving mode in which self-diagnosis is performed
during vehicle operation. Specific on board diagnostic items will cause the ECM to light up or blink the MIL,
and store DTC and Freeze Frame data, even in the 1st trip, as shown below.
×: Applicable —: Not applicable
When there is an open circuit on MIL circuit, the ECM cannot warn the driver by lighting up MIL when there is
malfunction on engine control system.
Emission-related diagnostic information Diagnostic service
Diagnostic Trouble Code (DTC) Service $03 of SAE J1979
Freeze Frame data Service $02 of SAE J1979
System Readiness Test (SRT) code Service $01 of SAE J1979
1st Trip Diagnostic Trouble Code (1st Trip DTC) Service $07 of SAE J1979
1st Trip Freeze Frame data
Test values and Test limits Service $06 of SAE J1979
Calibration ID Service $09 of SAE J1979
DTC 1st trip DTCFreeze
Frame data1st trip Freeze
Frame dataSRT code SRT status Test value
CONSULT-II×× × × × ×—
GST×× ×—×××
ECM××*— — —×—
ItemsMIL DTC 1st trip DTC
1st trip 2nd trip
1st trip
displaying2nd trip
displaying1st trip
displaying2nd trip
display-
ing BlinkingLighting
upBlinkingLighting
up
Misfire (Possible three way catalyst
damage) — DTC: P0300 - P0308 is
being detected×———— —×—
Misfire (Possible three way catalyst
damage) — DTC: P0300 - P0308 is
being detected——×——×——
One trip detection diagnoses (Re-
fer to EC-49, "
Emission-related Di-
agnostic Information".)—×——×———
Except above — — —×—××—