2005 INFINITI QX4 fuel pressure

EC-4Revision: October 20052005 QX56 Diagnostic Procedure ...........................................338
Component Inspection ..........................................340
DTC P0453 EVAP CONTROL SYSTEM PRESSURE
SENSOR ..................................................................341
Component Description ........................................341
CONSULT-II Reference Value in Data Monitor Mode
.341
On Board Diagnosis Logic ....................................341
DTC Confirmation Procedure ...............................342
Wiring Diagram .....................................................343
Diagnostic Procedure ...........................................344
Component Inspection ..........................................348
DTC P0455 EVAP CONTROL SYSTEM .................349
On Board Diagnosis Logic ....................................349
DTC Confirmation Procedure ...............................350
Diagnostic Procedure ...........................................351
DTC P0456 EVAP CONTROL SYSTEM .................357
On Board Diagnosis Logic ....................................357
DTC Confirmation Procedure ...............................358
Overall Function Check ........................................359
Diagnostic Procedure ...........................................360
DTC P0460 FUEL LEVEL SENSOR .......................366
Component Description ........................................366
On Board Diagnosis Logic ....................................366
DTC Confirmation Procedure ...............................366
Diagnostic Procedure ...........................................367
Removal and Installation ......................................367
DTC P0461 FUEL LEVEL SENSOR .......................368
Component Description ........................................368
On Board Diagnosis Logic ....................................368
Overall Function Check ........................................368
Diagnostic Procedure ...........................................369
Removal and Installation ......................................369
DTC P0462, P0463 FUEL LEVEL SENSOR CIR-
CUIT ........................................................................370
Component Description ........................................370
On Board Diagnosis Logic ....................................370
DTC Confirmation Procedure ...............................370
Diagnostic Procedure ...........................................371
Removal and Installation ......................................371
DTC P0500 VSS ......................................................372
Description ............................................................372
On Board Diagnosis Logic ....................................372
DTC Confirmation Procedure ...............................372
Overall Function Check ........................................372
Diagnostic Procedure ...........................................373
DTC P0506 ISC SYSTEM .......................................374
Description ............................................................374
On Board Diagnosis Logic ....................................374
DTC Confirmation Procedure ...............................374
Diagnostic Procedure ...........................................375
DTC P0507 ISC SYSTEM .......................................376
Description ............................................................376
On Board Diagnosis Logic ....................................376
DTC Confirmation Procedure ...............................376
Diagnostic Procedure ...........................................377
DTC P0550 PSP SENSOR ......................................378
Component Description ........................................378
CONSULT-II Reference Value in Data Monitor Mode . 378
On Board Diagnosis Logic .................................... 378
DTC Confirmation Procedure ................................ 378
Wiring Diagram ..................................................... 379
Diagnostic Procedure ............................................ 380
Component Inspection .......................................... 382
Removal and Installation ....................................... 382
DTC P0605 ECM ..................................................... 383
Component Description ........................................ 383
On Board Diagnosis Logic .................................... 383
DTC Confirmation Procedure ................................ 383
Diagnostic Procedure ............................................ 384
DTC P1031, P1032, P1051, P1052 A/F SENSOR 1
HEATER ................................................................... 386
Description ............................................................ 386
CONSULT-II Reference Value in Data Monitor Mode
. 386
On Board Diagnosis Logic .................................... 386
DTC Confirmation Procedure ................................ 386
Wiring Diagram ..................................................... 387
Diagnostic Procedure ............................................ 390
Component Inspection .......................................... 392
Removal and Installation ....................................... 392
DTC P1065 ECM POWER SUPPLY ........................ 393
Component Description ........................................ 393
On Board Diagnosis Logic .................................... 393
DTC Confirmation Procedure ................................ 393
Wiring Diagram ..................................................... 394
Diagnostic Procedure ............................................ 395
DTC P1121 ELECTRIC THROTTLE CONTROL
ACTUATOR ............................................................. 397
Component Description ........................................ 397
On Board Diagnosis Logic .................................... 397
DTC Confirmation Procedure ................................ 397
Diagnostic Procedure ............................................ 398
DTC P1122 ELECTRIC THROTTLE CONTROL
FUNCTION .............................................................. 399
Description ............................................................ 399
On Board Diagnosis Logic .................................... 399
DTC Confirmation Procedure ................................ 399
Wiring Diagram ..................................................... 400
Diagnostic Procedure ............................................ 401
Component Inspection .......................................... 404
Removal and Installation ....................................... 404
DTC P1124, P1126 THROTTLE CONTROL MOTOR
RELAY ..................................................................... 405
Component Description ........................................ 405
CONSULT-II Reference Value in Data Monitor Mode
. 405
On Board Diagnosis Logic .................................... 405
DTC Confirmation Procedure ................................ 405
Wiring Diagram ..................................................... 407
Diagnostic Procedure ............................................ 408
DTC P1128 THROTTLE CONTROL MOTOR ......... 410
Component Description ........................................ 410
On Board Diagnosis Logic .................................... 410
DTC Confirmation Procedure ................................ 410
Wiring Diagram .....................................................411
Diagnostic Procedure ............................................ 412

EC-7
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Revision: October 20052005 QX56 DTC P2135 TP SENSOR ........................................ 604
Component Description ........................................ 604
CONSULT-II Reference Value in Data Monitor Mode
. 604
On Board Diagnosis Logic ................................... 604
DTC Confirmation Procedure ............................... 605
Wiring Diagram .................................................... 606
Diagnostic Procedure ........................................... 607
Component Inspection ......................................... 610
Removal and Installation ...................................... 610
DTC P2138 APP SENSOR ...................................... 611
Component Description ......................................... 611
CONSULT-II Reference Value in Data Monitor Mode
.. 611
On Board Diagnosis Logic .................................... 611
DTC Confirmation Procedure ............................... 612
Wiring Diagram .................................................... 613
Diagnostic Procedure ........................................... 614
Component Inspection ......................................... 618
Removal and Installation ...................................... 618
IGNITION SIGNAL .................................................. 619
Component Description ........................................ 619
Wiring Diagram .................................................... 620
Diagnostic Procedure ........................................... 625
Component Inspection ......................................... 629
Removal and Installation ...................................... 630
INJECTOR CIRCUIT ............................................... 631
Component Description ........................................ 631
CONSULT-II Reference Value in Data Monitor Mode
. 631
Wiring Diagram .................................................... 632
Diagnostic Procedure ........................................... 633
Component Inspection ......................................... 636
Removal and Installation ...................................... 636
FUEL PUMP CIRCUIT ............................................ 637
Description ........................................................... 637
CONSULT-II Reference Value in Data Monitor Mode
. 637
Wiring Diagram .................................................... 638
Diagnostic Procedure ........................................... 639
Component Inspection ......................................... 642
Removal and Installation ...................................... 642
REFRIGERANT PRESSURE SENSOR ................. 643
Component Description ........................................ 643Wiring Diagram .....................................................644
Diagnostic Procedure ...........................................645
Removal and Installation ......................................647
ELECTRICAL LOAD SIGNAL ................................648
Description ............................................................648
CONSULT-II Reference Value in Data Monitor Mode
.648
Diagnostic Procedure ...........................................648
ICC BRAKE SWITCH .............................................649
Component Description ........................................649
CONSULT-II Reference Value in Data Monitor Mode
.649
Wiring Diagram .....................................................650
Diagnostic Procedure ...........................................651
Component Inspection ..........................................656
ASCD BRAKE SWITCH .........................................657
Component Description ........................................657
CONSULT-II Reference Value in Data Monitor Mode
.657
Wiring Diagram .....................................................658
Diagnostic Procedure ...........................................659
Component Inspection ..........................................663
ASCD INDICATOR ..................................................664
Component Description ........................................664
CONSULT-II Reference Value in Data Monitor Mode
.664
Wiring Diagram .....................................................665
Diagnostic Procedure ...........................................666
MIL AND DATA LINK CONNECTOR ......................667
Wiring Diagram .....................................................667
SERVICE DATA AND SPECIFICATIONS (SDS) ....669
Fuel Pressure .......................................................669
Idle Speed and Ignition Timing .............................669
Calculated Load Value ..........................................669
Mass Air Flow Sensor ...........................................669
Intake Air Temperature Sensor .............................669
Engine Coolant Temperature Sensor ...................669
A/F Sensor 1 Heater .............................................669
Heated Oxygen sensor 2 Heater ..........................669
Crankshaft Position Sensor (POS) .......................669
Camshaft Position Sensor (PHASE) ....................669
Throttle Control Motor ...........................................669
Injector ..................................................................670
Fuel Pump ............................................................670

EC-20Revision: October 2005
PREPARATION
2005 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 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

EC-22Revision: October 2005
PREPARATION
2005 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

EC-24Revision: October 2005
ENGINE CONTROL SYSTEM
2005 QX56
Multiport Fuel Injection (MFI) SystemUBS00KZ7
INPUT/OUTPUT SIGNAL CHART
*1: This sensor is not used to control the engine system. This is used only for the on board diagnosis.
*2: This signal is sent to the ECM through CAN communication line.
*3: ECM determines the start signal status by the signals of engine speed and battery voltage.
SYSTEM DESCRIPTION
The amount of fuel injected from the fuel injector is determined by the ECM. The ECM controls the length of
time the valve remains open (injection pulse duration). The amount of fuel injected is a program value in the
ECM memory. The program value is preset by engine operating conditions. These conditions are determined
by input signals (for engine speed and intake air) from both the crankshaft position sensor and the mass air
flow sensor.
VARIOUS FUEL INJECTION INCREASE/DECREASE COMPENSATION
In addition, the amount of fuel injected is compensated to improve engine performance under various operat-
ing conditions as listed below.


During warm-up

When starting the engine

During acceleration

Hot-engine operation

When selector lever is changed from N to D

High-load, high-speed operation


During deceleration

During high engine speed operation
Sensor Input signal to ECM ECM function Actuator
Crankshaft position sensor (POS)
Engine speed*
3
Piston position
Fuel injection
& mixture ratio
controlFuel injector Camshaft position sensor (PHASE)
Mass air flow sensor Amount of intake air
Engine coolant temperature sensor Engine coolant temperature
Air fuel ratio (A/F) sensor 1 Density of oxygen in exhaust gas
Throttle position sensor Throttle position
Accelerator pedal position sensor Accelerator pedal position
Park/neutral position (PNP) switch Gear position
Knock sensor Engine knocking condition
Battery
Battery voltage*
3
Power steering pressure sensor Power steering operation
Heated oxygen sensor 2*
1Density of oxygen in exhaust gas
ABS actuator and electric unit (control unit)*
2VDC/TCS operation command
Air conditioner switch*
2Air conditioner operation
Wheel sensor*
2Vehicle speed

EVAPORATIVE EMISSION SYSTEM
EC-35
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EC
Revision: October 20052005 QX56
Component InspectionUBS00KZG
EVAP CANISTER
Check EVAP canister as follows:
1. Block port B .
2. Blow air into port A and check that it flows freely out of port C .
3. Release blocked port B .
4. Apply vacuum pressure to port B and check that vacuum pres-
sure exists at the ports A and C .
5. Block port A and B .
6. Apply pressure to port C and check that there is no leakage.
FUEL TANK VACUUM RELIEF VALVE (BUILT INTO FUEL FULLER CAP)
1. Wipe clean valve housing.
2. Check valve opening pressure and vacuum.
3. If out of specification, replace fuel filler cap as an assembly.
CAUTION:
Use only a genuine fuel filler cap as a replacement. If an incor-
rect fuel filler cap is used, the MIL may come on.
EVAP CANISTER PURGE VOLUME CONTROL SOLENOID VALVE
Refer to EC-318 and EC-531 .
FUEL TANK TEMPERATURE SENSOR
Refer to EC-253 and EC-259 .
EVAP CANISTER VENT CONTROL VALVE
Refer to EC-325 and EC-539 .
EVAP CONTROL SYSTEM PRESSURE SENSOR
Refer to EC-332 , EC-335 and EC-341 .
PBIB1212E
SEF 4 45 Y
Pressure:
15.3 - 20.0 kPa (0.156 - 0.204 kg/cm2 , 2.22
- 2.90 psi)
Va c u u m :
−6.0 to −3.3 kPa (−0.061 to −0.034 kg/cm
2 ,
−0.87 to −0.48 psi)
SEF 9 43 S

EC-36Revision: October 2005
EVAPORATIVE EMISSION SYSTEM
2005 QX56
EVAP SERVICE PORT
Positive pressure is delivered to the EVAP system through the EVAP
service port. If fuel vapor leakage in the EVAP system occurs, use a
leak detector to locate the leak.
Removal and InstallationUBS00KZH
EVAP CANISTER
Tighten EVAP canister as shown in the figure.
EVAP CANISTER VENT CONTROL VALVE
1. Turn EVAP canister vent control valve counterclockwise.
2. Remove the EVAP canister vent control valve.
Always replace O-ring with a new one.
BBIA0366E
: N-·m (kg-m, in-lb)
BBIA0349E
BBIA0350E

EVAPORATIVE EMISSION SYSTEM
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How to Detect Fuel Vapor LeakageUBS00KZI
CAUTION:

Never use compressed air or a high pressure pump.

Do not exceed 4.12 kPa (0.042 kg/cm2 , 0.6 psi) of pressure in EVAP system.
NOTE:

Do not start engine.

Improper installation of EVAP service port adapter to the EVAP service port may cause a leak.
WITH CONSULT-II
1. Attach the EVAP service port adapter securely to the EVAP service port.
2. Also attach the pressure pump and hose to the EVAP service port adapter.
3. Turn ignition switch ON.
4. Select the “EVAP SYSTEM CLOSE” of “WORK SUPPORT
MODE” with CONSULT-II.
5. Touch “START”. A bar graph (Pressure indicating display) will
appear on the screen.
6. Apply positive pressure to the EVAP system until the pressure
indicator reaches the middle of the bar graph.
7. Remove EVAP service port adapter and hose with pressure
pump.
8. Locate the leak using a leak detector. Refer to EC-33, "
EVAPO-
RATIVE EMISSION LINE DRAWING" .
PEF 8 38 U
PEF 9 17 U
SEF 2 00 U