DI-38
WARNING LAMPS
Revision: August 20072004 QX56
Oil Pressure Warning Lamp Stays Off (Ignition Switch ON)EKS007EA
1. CHECK OIL PRESSURE SENSOR SIGNAL
1. Turn ignition switch ON.
2. Check voltage between combination meter harness connector
M24 terminal 20 (Y) and ground.
OK or NG
OK >> GO TO 2.
NG >> GO TO 3.
2. CHECK OIL PRESSURE SENSOR GROUND CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect combination meter connector M24 and oil pressure
sensor connector F4.
3. Check continuity between combination meter harness connector
M24 terminal 16 (B/P) and oil pressure sensor harness connec-
tor F4 terminal 3 (B/P).
OK or NG
OK >> Replace the combination meter. Refer to IP-13, "Combi-
nation Meter" .
NG >> Repair harness or connector.
3. CHECK OIL PRESSURE SENSOR REFERENCE VOLTAGE
1. Turn ignition switch OFF.
2. Disconnect oil pressure sensor connector F4.
3. Turn ignition switch ON.
4. Check voltage between combination meter harness connector
M24 terminal 22 (GR/L) and ground.
OK or NG
OK >> GO TO 4.
NG >> Replace the combination meter. Refer to IP-13, "
Combi-
nation Meter" .
Terminals
Condition Voltage (V) (+)
(–)
ConnectorTe r m i n a l
(Wire color)
M24 20 (Y) GroundWhen ignition switch is in ON
position. (Engine stopped)Ye s
Engine running. (Idle speed) Yes
WKIA1833E
Continuity should exist.
WKIA1837E
Voltage : Approx. 5V
WKIA1834E
EC-1
ENGINE CONTROL SYSTEM
B ENGINE
CONTENTS
C
D
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F
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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-6Revision: August 20072004 QX56 Component Inspection ..........................................503
Removal and Installation ......................................503
DTC P1446 EVAP CANISTER VENT CONTROL
VALVE .....................................................................504
Component Description ........................................504
CONSULT-II Reference Value in Data Monitor Mode
.504
On Board Diagnosis Logic ....................................504
DTC Confirmation Procedure ...............................505
Wiring Diagram .....................................................506
Diagnostic Procedure ...........................................507
Component Inspection ..........................................508
DTC P1564 ICC STEERING SWITCH ....................510
Component Description ........................................510
CONSULT-II Reference Value in Data Monitor Mode
.510
On Board Diagnosis Logic ....................................510
DTC Confirmation Procedure ...............................510
Wiring Diagram .....................................................512
Diagnostic Procedure ...........................................514
Component Inspection ..........................................516
DTC P1564 ASCD STEERING SWITCH ................517
Component Description ........................................517
CONSULT-II Reference Value in Data Monitor Mode
.517
On Board Diagnosis Logic ....................................517
DTC Confirmation Procedure ...............................518
Wiring Diagram .....................................................519
Diagnostic Procedure ...........................................521
Component Inspection ..........................................522
DTC P1568 ICC FUNCTION ...................................524
On Board Diagnosis Logic ....................................524
DTC Confirmation Procedure ...............................524
Diagnostic Procedure ...........................................524
DTC P1572 ICC BRAKE SWITCH ..........................525
Component Description ........................................525
CONSULT-II Reference Value in Data Monitor Mode
.525
On Board Diagnosis Logic ....................................525
DTC Confirmation Procedure ...............................525
Wiring Diagram .....................................................527
Diagnostic Procedure ...........................................528
Component Inspection ..........................................532
DTC P1572 ASCD BRAKE SWITCH ......................534
Component Description ........................................534
CONSULT-II Reference Value in Data Monitor Mode
.534
On Board Diagnosis Logic ....................................534
DTC Confirmation Procedure ...............................535
Wiring Diagram .....................................................536
Diagnostic Procedure ...........................................537
Component Inspection ..........................................541
DTC P1574 ICC VEHICLE SPEED SENSOR .........542
Component Description ........................................542
On Board Diagnosis Logic ....................................542
DTC Confirmation Procedure ...............................542
Diagnostic Procedure ...........................................543
DTC P1574 ASCD VEHICLE SPEED SENSOR .....544
Component Description ........................................544On Board Diagnosis Logic .................................... 544
DTC Confirmation Procedure ................................ 544
Diagnostic Procedure ............................................ 545
DTC P1706 PNP SWITCH ....................................... 546
Component Description ........................................ 546
CONSULT-II Reference Value in Data Monitor Mode
. 546
On Board Diagnosis Logic .................................... 546
DTC Confirmation Procedure ................................ 546
Overall Function Check ......................................... 547
Wiring Diagram ..................................................... 548
Diagnostic Procedure ............................................ 549
DTC P1805 BRAKE SWITCH ................................. 551
Description ............................................................ 551
CONSULT-II Reference Value in Data Monitor Mode
. 551
On Board Diagnosis Logic .................................... 551
DTC Confirmation Procedure ................................ 551
Wiring Diagram ..................................................... 552
Diagnostic Procedure ............................................ 553
Component Inspection .......................................... 555
DTC P2122, P2123 APP SENSOR ......................... 556
Component Description ........................................ 556
CONSULT-II Reference Value in Data Monitor Mode
. 556
On Board Diagnosis Logic .................................... 556
DTC Confirmation Procedure ................................ 557
Wiring Diagram ..................................................... 558
Diagnostic Procedure ............................................ 559
Component Inspection .......................................... 561
Removal and Installation ....................................... 561
DTC P2127, P2128 APP SENSOR ......................... 562
Component Description ........................................ 562
CONSULT-II Reference Value in Data Monitor Mode
. 562
On Board Diagnosis Logic .................................... 562
DTC Confirmation Procedure ................................ 563
Wiring Diagram ..................................................... 564
Diagnostic Procedure ............................................ 565
Component Inspection .......................................... 568
Removal and Installation ....................................... 568
DTC P2135 TP SENSOR ........................................ 569
Component Description ........................................ 569
CONSULT-II Reference Value in Data Monitor Mode
. 569
On Board Diagnosis Logic .................................... 569
DTC Confirmation Procedure ................................ 570
Wiring Diagram ..................................................... 571
Diagnostic Procedure ............................................ 572
Component Inspection .......................................... 575
Removal and Installation ....................................... 575
DTC P2138 APP SENSOR ...................................... 576
Component Description ........................................ 576
CONSULT-II Reference Value in Data Monitor Mode
. 576
On Board Diagnosis Logic .................................... 576
DTC Confirmation Procedure ................................ 577
Wiring Diagram ..................................................... 578
Diagnostic Procedure ............................................ 579
EC-7
C
D
E
F
G
H
I
J
K
L
M
ECA
Revision: August 20072004 QX56 Component Inspection ......................................... 582
Removal and Installation ...................................... 582
IGNITION SIGNAL .................................................. 583
Component Description ........................................ 583
Wiring Diagram .................................................... 584
Diagnostic Procedure ........................................... 589
Component Inspection ......................................... 593
Removal and Installation ...................................... 594
INJECTOR CIRCUIT ............................................... 595
Component Description ........................................ 595
CONSULT-II Reference Value in Data Monitor Mode
. 595
Wiring Diagram .................................................... 596
Diagnostic Procedure ........................................... 597
Component Inspection ......................................... 600
Removal and Installation ...................................... 600
FUEL PUMP CIRCUIT ............................................ 601
Description ........................................................... 601
CONSULT-II Reference Value in Data Monitor Mode
. 601
Wiring Diagram .................................................... 602
Diagnostic Procedure ........................................... 603
Component Inspection ......................................... 606
Removal and Installation ...................................... 606
REFRIGERANT PRESSURE SENSOR ................. 607
Component Description ........................................ 607
Wiring Diagram .................................................... 608
Diagnostic Procedure ........................................... 609
Removal and Installation ....................................... 611
ELECTRICAL LOAD SIGNAL ................................ 612
Description ........................................................... 612
CONSULT-II Reference Value in Data Monitor Mode
. 612
Diagnostic Procedure ........................................... 612
ICC BRAKE SWITCH ............................................. 613
Component Description ........................................ 613
CONSULT-II Reference Value in Data Monitor Mode
. 613
Wiring Diagram .................................................... 614
Diagnostic Procedure ........................................... 615
Component Inspection ......................................... 619
ASCD BRAKE SWITCH ......................................... 621
Component Description ........................................ 621CONSULT-II Reference Value in Data Monitor Mode
.621
Wiring Diagram .....................................................622
Diagnostic Procedure ...........................................623
Component Inspection ..........................................627
ASCD INDICATOR ..................................................628
Component Description ........................................628
CONSULT-II Reference Value in Data Monitor Mode
.628
Wiring Diagram .....................................................629
Diagnostic Procedure ...........................................630
MIL AND DATA LINK CONNECTOR ......................631
Wiring Diagram .....................................................631
EVAPORATIVE EMISSION SYSTEM .....................633
Description ............................................................633
Component Inspection ..........................................636
Removal and Installation ......................................637
How to Detect Fuel Vapor Leakage ......................637
ON BOARD REFUELING VAPOR RECOVERY
(ORVR) ....................................................................640
System Description ...............................................640
Diagnostic Procedure ...........................................641
Component Inspection ..........................................643
POSITIVE CRANKCASE VENTILATION ...............645
Description ............................................................645
Component Inspection ..........................................645
AUTOMATIC SPEED CONTROL DEVICE (ASCD) .647
System Description ...............................................647
Component Description ........................................648
SERVICE DATA AND SPECIFICATIONS (SDS) ....649
Fuel Pressure .......................................................649
Idle Speed and Ignition Timing .............................649
Calculated Load Value ..........................................649
Mass Air Flow Sensor ...........................................649
Intake Air Temperature Sensor .............................649
Engine Coolant Temperature Sensor ...................649
A/F Sensor 1 Heater .............................................649
Heated Oxygen sensor 2 Heater ..........................649
Crankshaft Position Sensor (POS) .......................649
Camshaft Position Sensor (PHASE) ....................649
Throttle Control Motor ...........................................649
Injector ..................................................................650
Fuel Pump ............................................................650
INDEX FOR DTC
EC-11
C
D
E
F
G
H
I
J
K
L
MA
EC
Revision: August 20072004 QX56
*1: 1st trip DTC No. is the same as DTC No.
*2: This number is prescribed by SAE J2012.
*3: In Diagnostic Test Mode II (Self-diagnostic results). This number is controlled by NISSAN.
*4: The troubleshooting for this DTC needs CONSULT-II.
*5: When the fail-safe operations for both self-diagnoses occur at the same time, the MIL illuminates.
*6: 2WD models
*7: Models with ICC systemPW ST P SEN/CIRC P0550 0550 2 —EC-346
SENSOR POWER/CIRC P1229 1229 1×EC-424
TCC SOLENOID/CIRC P0740 0740 2×AT - 11 8
TCM P0700 0700 1×AT- 1 0 8
TCS C/U FUNCTN P1211 1211 2 —EC-408
TCS/CIRC P1212 1212 2 —EC-409
THERMSTAT FNCTN P0128 0128 2×EC-184
TP SEN 1/CIRC P0222 0222 1×EC-236
TP SEN 1/CIRC P0223 0223 1×EC-236
TP SEN 2/CIRC P0122 0122 1×EC-171
TP SEN 2/CIRC P0123 0123 1×EC-171
TP SENSOR P2135 2135 1×EC-569
TURBINE REV S/CIRC P1716 1716 2×AT- 1 3 4
TW CATALYST SYS-B1 P0420 0420 2×EC-267
TW CATALYST SYS-B2 P0430 0430 2×EC-267
VEH SPD SEN/CIR AT*5P0720 0720 2×AT - 11 2
VEH SPEED SEN/CIRC*5P0500 0500 2×EC-340
VENT CONTROL VALVE P0447 0447 2×EC-292
VENT CONTROL VALVE P1446 1446 2×EC-504
Items
(CONSULT-II screen terms)DTC*
1
TripMIL lighting
upReference page
CONSULT-II
GST*
2ECM*3
INDEX FOR DTC
EC-13
C
D
E
F
G
H
I
J
K
L
MA
EC
Revision: August 20072004 QX56P0304 0304 CYL 4 MISFIRE 2×EC-243
P0305 0305 CYL 5 MISFIRE 2×EC-243
P0306 0306 CYL 6 MISFIRE 2×EC-243
P0307 0307 CYL 7 MISFIRE 2×EC-243
P0308 0308 CYL 8 MISFIRE 2×EC-243
P0327 0327 KNOCK SEN/CIRC-B1 2 —EC-250
P0328 0328 KNOCK SEN/CIRC-B1 2 —EC-250
P0332 0332 KNOCK SEN/CIRC-B2 2 —EC-250
P0333 0333 KNOCK SEN/CIRC-B2 2 —EC-250
P0335 0335 CKP SEN/CIRCUIT 2×EC-255
P0340 0340 CMP SEN/CIRC-B1 2×EC-261
P0420 0420 TW CATALYST SYS-B1 2×EC-267
P0430 0430 TW CATALYST SYS-B2 2×EC-267
P0441 0441 EVAP PURG FLOW/MON 2×EC-271
P0442 0442 EVAP SMALL LEAK 2×EC-276
P0444 0444 PURG VOLUME CONT/V 2×EC-285
P0445 0445 PURG VOLUME CONT/V 2×EC-285
P0447 0447 VENT CONTROL VALVE 2×EC-292
P0451 0451 EVAP SYS PRES SEN 2×EC-299
P0452 0452 EVAP SYS PRES SEN 2×EC-302
P0453 0453 EVAP SYS PRES SEN 2×EC-308
P0455 0455 EVAP GROSS LEAK 2×EC-316
P0456 0456 EVAP VERY SML LEAK 2×EC-324
P0460 0460 FUEL LEV SEN SLOSH 2×EC-334
P0461 0461 FUEL LEVEL SENSOR 2×EC-336
P0462 0462 FUEL LEVL SEN/CIRC 2×EC-338
P0463 0463 FUEL LEVL SEN/CIRC 2×EC-338
P0500 0500
VEH SPEED SEN/CIRC*52×EC-340
P0506 0506 ISC SYSTEM 2×EC-342
P0507 0507 ISC SYSTEM 2×EC-344
P0550 0550 PW ST P SEN/CIRC 2 —EC-346
P0605 0605 ECM 1 or 2× or —EC-351
P0700 0700 TCM 1×AT- 1 0 8
P0705 0705 PNP SW/CIRC 2×AT- 1 0 9
P0710 0710 ATF TEMP SEN/CIRC 2×AT- 1 3 1
P0720 0720
VEH SPD SEN/CIR AT*52×AT - 11 2
P0740 0740 TCC SOLENOID/CIRC 2×AT - 11 8
P0744 0744 A/T TCC S/V FNCTN 2×AT- 1 2 1
P0745 0745 L/PRESS SOL/CIRC 2×AT- 1 2 4
P1031 1031 A/F SEN1 HTR (B1) 2×EC-354
P1032 1032 A/F SEN1 HTR (B1) 2×EC-354
P1051 1051 A/F SEN1 HTR (B2) 2×EC-354
DTC*1
Items
(CONSULT-II screen terms)TripMIL lighting
upReference page
CONSULT-II
GST*
2ECM*3
ENGINE CONTROL SYSTEM
EC-25
C
D
E
F
G
H
I
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K
L
MA
EC
Revision: August 20072004 QX56
System ChartUBS00GZD
*1: This sensor is not used to control the engine system. This is used only for the on board diagnosis.
*2: This sensor is not used to control the engine system under normal conditions.
*3: This input signal is sent to the ECM through CAN communication line.
*4: This output signal is sent from the ECM through CAN communication line.Input (Sensor) ECM Function Output (Actuator)
Camshaft position sensor (PHASE)
Crankshaft position sensor (POS)
Mass air flow sensor
Engine coolant temperature sensor
A/F sensor 1
Throttle position sensor
Accelerator pedal position sensor
Park/neutral position (PNP) switch
Intake air temperature sensor
Power steering pressure sensor
Ignition switch
Battery voltage
Knock sensor
Refrigerant pressure sensor
Stop lamp switch
ASCD steering switch
ASCD brake switch
Fuel level sensor*1 *3
EVAP control system pressure sensor
Fuel tank temperature sensor*1
Heated oxygen sensor 2*2
TCM (Transmission control module)*3
ABS actuator and electric unit (control unit)*3
Air conditioner switch*3
Wheel sensor*3
Electrical load signal*3
Fuel injection & mixture ratio control Fuel injector
Electronic ignition system Power transistor
Nissan torque demand control system
Electric throttle control actuator
Fuel injector
Fuel pump control Fuel pump relay
ASCD vehicle speed control Electric throttle control actuator
On board diagnostic system
MIL (On the instrument panel)*
4
A/F sensor 1 heater control A/F sensor 1 heater
Heated oxygen sensor 2 heater control Heated oxygen sensor 2 heater
EVAP canister purge flow controlEVAP canister purge volume control
solenoid valve
Air conditioning cut control
Air conditioner relay*
4
Cooling fan control
Cooling fan relay*4
ON BOARD DIAGNOSIS for EVAP system EVAP canister vent control valve
EC-26Revision: August 2007
ENGINE CONTROL SYSTEM
2004 QX56
Multiport Fuel Injection (MFI) SystemUBS00GZE
INPUT/OUTPUT SIGNAL CHART
*1: This sensor is not used to control the engine system under normal conditions.
*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 (POS), camshaft
position sensor (PHASE) 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
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