check engine INFINITI QX56 2006 Factory Service Manual

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

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-20Revision: November 2009
PREPARATION
2006 QX56
PREPARATIONPFP:00002
Special Service ToolsUBS00KZ4
The actual shapes of Kent-Moore tools may differ from those of special service tools illustrated here.Tool number
(Kent-Moore No.)
Tool name Description
EG17650301
(J-33984-A)
Radiator cap tester
adapter Adapting 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
wrench Loosening or tightening heated oxygen sensors
with 22 mm (0.87 in) hexagon nut
KV10114400
(J-38365)
Heated oxygen sensor
wrench Loosening or tightening heated oxygen sensors
a: 22 mm (0.87 in)
(J-44626)
Air fuel ratio (A/F) sen-
sor wrench Loosening or tightening air fuel ratio (A/F) sensor 1
(J-44321)
Fuel pressure gauge
kit Checking fuel pressure
(J-44321-6)
Fuel pressure adapter Connecting fuel pressure gauge to quick connec-
tor type fuel lines.
(J-45488)
Quick connector re-
lease Remove fuel tube quick connectors in engine
room.
S-NT564
S-NT379
S-NT636
LEM054
LEC642
LBIA0376E
PBIC0198E

PREPARATIONEC-21
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Revision: November 2009 2006 QX56
KV109E0010
(J-46209)
Break-out boxMeasuring the ECM signals with a circuit tester
KV109E0080
(J-45819)
Y-cable adapter Measuring the ECM signals with a circuit tester
(J-23688)
Engine coolant refrac-
tometer Checking concentration of ethylene glycol in en-
gine coolant
Tool number
(Kent-Moore No.)
Tool name
Description
S-NT825
S-NT826
WBIA0539E

EC-22Revision: November 2009
PREPARATION
2006 QX56
Commercial Service ToolsUBS00KZ5
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

ON BOARD REFUELING VAPOR RECOVERY (ORVR)EC-39
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ON BOARD REFUELING VAPOR RECOVERY (ORVR)PFP:00032
System DescriptionUBS00KZJ
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: INFLAMMABLE” 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 CO2 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 RELEASE" .
–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.
PBIB1068E

EC-48Revision: November 2009
ON BOARD DIAGNOSTIC (OBD) SYSTEM
2006 QX56
ON BOARD DIAGNOSTIC (OBD) SYSTEMPFP:00028
IntroductionUBS00KZP
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-91,
"Fail-safe Chart" .)
Two Trip Detection LogicUBS00KZQ
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 data 1st trip Freeze
Frame data SRT code SRT status Test value
CONSULT-II ×× × × × × —
GST ×× × —×××
ECM ××*——— ×—
Items MIL
DTC1st trip DTC
1st trip 2nd trip
1st trip
displaying 2nd trip
displaying 1st trip
displaying 2nd trip
display-
ing
Blinking Lighting
up Blinking Lighting
up
Misfire (Possible three way cata-
lyst damage) — DTC: P0300 -
P0308 is being detected ×
———— — ×—
Misfire (Possible three way cata-
lyst damage) — DTC: P0300 -
P0308 is being detected ——
×—— ×——
One trip detection diagnoses
(Refer to EC-49, "
EMISSION-
RELATED DIAGNOSTIC INFOR-
MATION ITEMS" .) —
×—— ×———
Except above ———×— ×× —

ON BOARD DIAGNOSTIC (OBD) SYSTEMEC-53
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If a malfunction is detected during the 1st trip, the 1st trip DTC is stored in the ECM memory. The MIL will not
light up (two trip detection logic). If the same malfunction is not detected in the 2nd trip (meeting the required
driving pattern), the 1st trip DTC is cleared from the ECM memory. If the same malfunction is detected in the
2nd trip, both the 1st trip DTC and DTC are stored in the ECM memory and the MIL lights up. In other words,
the DTC is stored in the ECM memory and the MIL lights up when the same malfunction occurs in two consec-
utive trips. If a 1st trip DTC is stored and a non-diagnostic operation is performed between the 1st and 2nd
trips, only the 1st trip DTC will continue to be stored. For malfunctions that blink or light up the MIL during the
1st trip, the DTC and 1st trip DTC are stored in the ECM memory.
Procedures for clearing the DTC and the 1st trip DTC from the ECM memory are described in EC-61, "
HOW
TO ERASE EMISSION-RELATED DIAGNOSTIC INFORMATION" .
For malfunctions in which 1st trip DTCs are displayed, refer to EC-49, "
EMISSION-RELATED DIAGNOSTIC
INFORMATION ITEMS" . These items are required by legal regulations to continuously monitor the system/
component. In addition, the items monitored non-continuously are also displayed on CONSULT-II.
1st trip DTC is specified in Service $07 of SAE J1979. 1st trip DTC detection occurs without lighting up the MIL
and therefore does not warn the driver of a malfunction. However, 1st trip DTC detection will not prevent the
vehicle from being tested, for example during Inspection/Maintenance (I/M) tests.
When a 1st trip DTC is detected, check, print out or write down and erase (1st trip) DTC and Freeze Frame
data as specified in Work Flow procedure Step 2, refer to EC-84, "
WORK FLOW" . Then perform DTC Confir-
mation Procedure or Overall Function Check to try to duplicate the malfunction. If the malfunction is dupli-
cated, the item requires repair.
How to Read DTC and 1st Trip DTC
DTC and 1st trip DTC can be read by the following methods.
With CONSULT-II
With GST
CONSULT-II or GST (Generic Scan Tool) Examples: P0340, P0850, P1148, etc.
These DTCs are prescribed by SAE J2012.
(CONSULT-II also displays the malfunctioning component or system.)
No Tools
The number of blinks of the MIL in the Diagnostic Test Mode II (Self-Diagnostic Results) indicates the DTC.
Example: 0340, 0850, 1148, etc.
These DTCs are controlled by NISSAN.

1st trip DTC No. is the same as DTC No.

Output of a DTC indicates a malfunction. However, GST or the Diagnostic Test Mode II do not indi-
cate whether the malfunction is still occurring or has occurred in the past and has returned to nor-
mal. CONSULT-II can identify malfunction status as shown below. Therefore, using CONSULT-II (if
available) is recommended.
A sample of CONSULT-II display for DTC and 1st trip DTC is shown below. DTC or 1st trip DTC of a malfunc-
tion is displayed in SELF-DIAGNOSTIC RESULTS mode of CONSULT-II. Time data indicates how many times
the vehicle was driven after the last detection of a DTC.
If the DTC is being detected currently, the time data will be [0].
If a 1st trip DTC is stored in the ECM, the time data will be [1t].
FREEZE FRAME DATA AND 1ST TRIP FREEZE FRAME DATA
The ECM records the driving conditions such as fuel system status, calculated load value, engine coolant tem-
perature, short term fuel trim, long term fuel trim, engine speed, vehicle speed, absolute throttle position, base
fuel schedule and intake air temperature at the moment a malfunction is detected.
Data which are stored in the ECM memory, along with the 1st trip DTC, are called 1st trip freeze frame data.
The data, stored together with the DTC data, are called freeze frame data and displayed on CONSULT-II or
PBIB0911E