engine INFINITI QX4 2001 Factory Service Manual

ENGINE COMPARTMENTNBBT0021S01MeasurementNBBT0021S0101
SBT194
BODY (ALIGNMENT)
Alignment (Cont'd)
BT-58

ENGINE CONTROL SYSTEM
SECTION
EC
CONTENTS
TROUBLE DIAGNOSIS - INDEX....................................8
Alphabetical & P No. Index for DTC ...........................8
PRECAUTIONS.............................................................14
Supplemental Restraint System (SRS)²AIR
BAG²and²SEAT BELT PRE-TENSIONER².............14
Precautions for On Board Diagnostic (OBD)
System of Engine and A/T.........................................14
Engine Fuel & Emission Control System ..................15
Precautions ................................................................16
Wiring Diagrams and Trouble Diagnosis ...................17
PREPARATION.............................................................18
Special Service Tools ................................................18
Commercial Service Tools .........................................18
ENGINE AND EMISSION CONTROL OVERALL
SYSTEM.........................................................................20
Engine Control Component Parts Location ...............20
Circuit Diagram ..........................................................24
System Diagram ........................................................25
Vacuum Hose Drawing ..............................................26
System Chart .............................................................27
ENGINE AND EMISSION BASIC CONTROL
SYSTEM DESCRIPTION...............................................28
Multiport Fuel Injection (MFI) System .......................28
Electronic Ignition (EI) System ..................................30
Air Conditioning Cut Control ......................................31
Fuel Cut Control (at no load & high engine
speed) ........................................................................32
Evaporative Emission System ...................................32
Positive Crankcase Ventilation ..................................38
BASIC SERVICE PROCEDURE...................................39
Fuel Pressure Release ..............................................39
Fuel Pressure Check .................................................39
Fuel Pressure Regulator Check ................................40
Injector .......................................................................41
How to Check Idle Speed and Ignition Timing ..........42
Idle Speed/Ignition Timing/Idle Mixture Ratio
Adjustment .................................................................43
Idle Air Volume Learning ...........................................57ON BOARD DIAGNOSTIC SYSTEM
DESCRIPTION...............................................................59
Introduction ................................................................59
Two Trip Detection Logic ...........................................59
Emission-related Diagnostic Information ...................60
Malfunction Indicator Lamp (MIL) ..............................74
OBD System Operation Chart ...................................75
CONSULT-II ...............................................................81
Generic Scan Tool (GST) ..........................................95
TROUBLE DIAGNOSIS - INTRODUCTION..................97
Introduction ................................................................97
Work Flow ..................................................................99
TROUBLE DIAGNOSIS - BASIC INSPECTION.........101
Basic Inspection.......................................................101
TROUBLE DIAGNOSIS - GENERAL
DESCRIPTION............................................................. 116
DTC Inspection Priority Chart.................................. 116
Fail-safe Chart ......................................................... 117
Symptom Matrix Chart ............................................. 118
CONSULT-II Reference Value in Data Monitor
Mode ........................................................................122
Major Sensor Reference Graph in Data Monitor
Mode ........................................................................124
ECM Terminals and Reference Value .....................127
TROUBLE DIAGNOSIS - SPECIFICATION VALUE..136
Description ...............................................................136
Testing Condition .....................................................136
Inspection Procedure ...............................................136
Diagnostic Procedure ..............................................137
TROUBLE DIAGNOSIS FOR INTERMITTENT
INCIDENT.....................................................................140
Description ...............................................................140
Diagnostic Procedure ..............................................140
TROUBLE DIAGNOSIS FOR POWER SUPPLY........141
ECM Terminals and Reference Value .....................141
Main Power Supply and Ground Circuit ..................142
DTC P0100 MASS AIR FLOW SENSOR (MAFS)......150
Component Description ...........................................150
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CONSULT-II Reference Value in Data Monitor
Mode ........................................................................150
ECM Terminals and Reference Value .....................150
On Board Diagnosis Logic.......................................151
Possible Cause ........................................................151
DTC Confirmation Procedure ..................................151
Overall Function Check ...........................................153
Wiring Diagram ........................................................154
Diagnostic Procedure ..............................................155
DTC P0105 ABSOLUTE PRESSURE SENSOR........158
Component Description ...........................................158
ECM Terminals and Reference Value .....................158
On Board Diagnosis Logic.......................................158
Possible Cause ........................................................159
DTC Confirmation Procedure ..................................159
Wiring Diagram ........................................................160
Diagnostic Procedure ..............................................161
DTC P0110 INTAKE AIR TEMPERATURE
SENSOR......................................................................164
Component Description ...........................................164
On Board Diagnosis Logic.......................................164
Possible Cause ........................................................164
DTC Confirmation Procedure ..................................164
Wiring Diagram ........................................................166
Diagnostic Procedure ..............................................167
DTC P0115 ENGINE COOLANT TEMPERATURE
SENSOR (ECTS) (CIRCUIT).......................................169
Component Description ...........................................169
On Board Diagnosis Logic.......................................169
Possible Cause ........................................................170
DTC Confirmation Procedure ..................................170
Wiring Diagram ........................................................171
Diagnostic Procedure ..............................................172
DTC P0120 THROTTLE POSITION SENSOR...........174
Description ...............................................................174
CONSULT-II Reference Value in Data Monitor
Mode ........................................................................174
ECM Terminals and Reference Value .....................175
On Board Diagnosis Logic.......................................175
Possible Cause ........................................................175
DTC Confirmation Procedure ..................................176
Wiring Diagram ........................................................180
Diagnostic Procedure ..............................................181
DTC P0125 ENGINE COOLANT TEMPERATURE
SENSOR (ECTS).........................................................187
Description ...............................................................187
On Board Diagnosis Logic.......................................187
Possible Cause ........................................................188
DTC Confirmation Procedure ..................................188
Wiring Diagram ........................................................189
Diagnostic Procedure ..............................................190DTC P0130, P0150 HEATED OXYGEN SENSOR 1
(FRONT) (BANK 1)/(BANK 2) (CIRCUIT)..................192
Component Description ...........................................192
CONSULT-II Reference Value in Data Monitor
Mode ........................................................................192
ECM Terminals and Reference Value .....................192
On Board Diagnosis Logic.......................................193
Possible Cause ........................................................193
DTC Confirmation Procedure ..................................194
Overall Function Check ...........................................194
Wiring Diagram ........................................................196
Diagnostic Procedure ..............................................198
DTC P0131, P0151 HEATED OXYGEN SENSOR 1
(FRONT) (BANK 1)/(BANK 2) (LEAN SHIFT
MONITORING).............................................................202
Component Description ...........................................202
CONSULT-II Reference Value in Data Monitor
Mode ........................................................................202
ECM Terminals and Reference Value .....................202
On Board Diagnosis Logic.......................................203
Possible Cause ........................................................203
DTC Confirmation Procedure ..................................203
Overall Function Check ...........................................204
Diagnostic Procedure ..............................................205
DTC P0132, P0152 HEATED OXYGEN SENSOR 1
(FRONT) (BANK 1)/(BANK 2) (RICH SHIFT
MONITORING).............................................................210
Component Description ...........................................210
CONSULT-II Reference Value in Data Monitor
Mode ........................................................................210
ECM Terminals and Reference Value .....................210
On Board Diagnosis Logic....................................... 211
Possible Cause ........................................................ 211
DTC Confirmation Procedure .................................. 211
Overall Function Check ...........................................212
Diagnostic Procedure ..............................................213
DTC P0133, P0153 HEATED OXYGEN SENSOR 1
(FRONT) (BANK 1)/(BANK 2) (RESPONSE
MONITORING).............................................................218
Component Description ...........................................218
CONSULT-II Reference Value in Data Monitor
Mode ........................................................................218
ECM Terminals and Reference Value .....................218
On Board Diagnosis Logic.......................................219
Possible Cause ........................................................219
DTC Confirmation Procedure ..................................220
Overall Function Check ...........................................221
Wiring Diagram ........................................................222
Diagnostic Procedure ..............................................224
DTC P0134, P0154 HEATED OXYGEN SENSOR 1
(FRONT) (BANK 1)/(BANK 2) (HIGH VOLTAGE)......231
Component Description ...........................................231
CONTENTS(Cont'd)
EC-2

CONSULT-II Reference Value in Data Monitor
Mode ........................................................................585
ECM Terminals and Reference Value .....................585
On Board Diagnosis Logic.......................................586
Possible Cause ........................................................586
DTC Confirmation Procedure ..................................586
Wiring Diagram ........................................................587
Diagnostic Procedure ..............................................588
DTC P1491 VACUUM CUT VALVE BYPASS
VALVE..........................................................................591
Description ...............................................................591
CONSULT-II Reference Value in Data Monitor
Mode ........................................................................591
ECM Terminals and Reference Value .....................591
On Board Diagnosis Logic.......................................592
Possible Cause ........................................................592
DTC Confirmation Procedure ..................................592
Overall Function Check ...........................................593
Wiring Diagram ........................................................594
Diagnostic Procedure ..............................................595
DTC P1605 A/T DIAGNOSIS COMMUNICATION
LINE.............................................................................603
Component Description ...........................................603
On Board Diagnosis Logic.......................................603
Possible Cause ........................................................603
DTC Confirmation Procedure ..................................603
DTC P1706 PARK/NEUTRAL POSITION (PNP)
SWITCH.......................................................................604
Component Description ...........................................604
CONSULT-II Reference Value in Data Monitor
Mode ........................................................................604
ECM Terminals and Reference Value .....................604
On Board Diagnosis Logic.......................................604
Possible Cause ........................................................604
DTC Confirmation Procedure ..................................605
Overall Function Check ...........................................606
Wiring Diagram ........................................................607
Diagnostic Procedure ..............................................608
VARIABLE INDUCTION AIR CONTROL SYSTEM
(VIAS)...........................................................................610
Description ...............................................................610
ECM Terminals and Reference Value ..................... 611
Wiring Diagram ........................................................612
Diagnostic Procedure ..............................................613
INJECTOR...................................................................616
Component Description ...........................................616
CONSULT-II Reference Value in Data Monitor
Mode ........................................................................616
ECM Terminals and Reference Value .....................616
Wiring Diagram ........................................................617Diagnostic Procedure ..............................................618
START SIGNAL...........................................................621
CONSULT-II Reference Value in Data Monitor
Mode ........................................................................621
ECM Terminals and Reference Value .....................621
Wiring Diagram ........................................................622
Diagnostic Procedure ..............................................623
FUEL PUMP.................................................................625
System Description ..................................................625
Component Description ...........................................625
CONSULT-II Reference Value in Data Monitor
Mode ........................................................................625
ECM Terminals and Reference Value .....................626
Wiring Diagram ........................................................627
Diagnostic Procedure ..............................................628
POWER STEERING OIL PRESSURE SWITCH.........634
Component Description ...........................................634
CONSULT-II Reference Value in Data Monitor
Mode ........................................................................634
ECM Terminals and Reference Value .....................634
Wiring Diagram ........................................................635
Diagnostic Procedure ..............................................636
REFRIGERANT PRESSURE SENSOR......................639
Description ...............................................................639
ECM Terminals and Reference Value .....................639
Wiring Diagram ........................................................640
Diagnostic Procedure ..............................................641
ELECTRICAL LOAD SIGNAL.....................................643
ECM Terminals and Reference Value .....................643
Wiring Diagram ........................................................644
Diagnostic Procedure ..............................................645
MIL & DATA LINK CONNECTORS............................648
Wiring Diagram ........................................................648
SERVICE DATA AND SPECIFICATIONS (SDS).......649
Fuel Pressure Regulator..........................................649
Idle Speed and Ignition Timing ................................649
Mass Air Flow Sensor..............................................649
Engine Coolant Temperature Sensor ......................649
Heated Oxygen Sensor 1 Heater (Front) ................649
Fuel Pump ...............................................................649
IACV-AAC Valve ......................................................649
Injector .....................................................................649
Resistor ....................................................................649
Throttle Position Sensor ..........................................650
Calculated Load Value.............................................650
Intake Air Temperature Sensor ................................650
Heated Oxygen Sensor 2 Heater (Rear).................650
Crankshaft Position Sensor (REF) ..........................650
Fuel Tank Temperature Sensor ...............................650
Camshaft Position Sensor (PHASE) .......................650GI
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CONTENTS(Cont'd)
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Alphabetical & P No. Index for DTCNBEC0001ALPHABETICAL INDEX FOR DTCNBEC0001S01
Items
(CONSULT-II screen terms)DTC*1 Reference page
Unable to access ECM Ð EC-117
ABSL PRES SEN/CIRC P0105 EC-158
AIR TEMP SEN/CIRC P0110 EC-164
A/T 1ST GR FNCTN P0731 AT-136
A/T 2ND GR FNCTN P0732 AT-143
A/T 3RD GR FNCTN P0733 AT-151
A/T 4TH GR FNCTN P0734 AT-157
A/T COMM LINE P0600*2 EC-440
A/T DIAG COMM LINE P1605 EC-603
A/T TCC S/V FNCTN P0744 AT-170
ATF TEMP SEN/CIRC P0710 AT-116
CAM PS/CIRC (PHS) P0340 EC-342
CLOSED LOOP-B1 P1148 EC-491
CLOSED LOOP-B2 P1168 EC-491
CLOSED TP SW/CIRC P0510 EC-431
COOLANT T SEN/CIRC*3 P0115 EC-169
*COOLANT T SEN/CIRC P0125 EC-187
CPS/CIRC (POS) COG P1336 EC-517
CPS/CIRCUIT (POS) P0335 EC-334
CPS/CIRCUIT (REF) P1335 EC-510
CYL 1 MISFIRE P0301 EC-320
CYL 2 MISFIRE P0302 EC-320
CYL 3 MISFIRE P0303 EC-320
CYL 4 MISFIRE P0304 EC-320
CYL 5 MISFIRE P0305 EC-320
CYL 6 MISFIRE P0306 EC-320
ECMP0605 EC-444
ENGINE SPEED SIG P0725 AT-130
ENG OVER TEMP P0217 EC-314
ENG OVER TEMP P1217 LC-24
EVAP GROSS LEAK P0455 EC-394
EVAP PURG FLOW/MON P1447 EC-561
EVAP SYS PRES SEN P0450 EC-381
EVAP SMALL LEAK P0440 EC-352
EVAP VERY SMALL LEAK P1441 EC-526
TROUBLE DIAGNOSIS Ð INDEX
Alphabetical & P No. Index for DTC
EC-8

DTC*1Items
(CONSULT-II screen terms)Reference page
P0217 ENG OVER TEMP EC-314
P0300 MULTI CYL MISFIRE EC-320
P0301 CYL 1 MISFIRE EC-320
P0302 CYL 2 MISFIRE EC-320
P0303 CYL 3 MISFIRE EC-320
P0304 CYL 4 MISFIRE EC-320
P0305 CYL 5 MISFIRE EC-320
P0306 CYL 6 MISFIRE EC-320
P0325*2 KNOCK SEN/CIRC-B1 EC-328
P0335 CPS/CIRCUIT (POS) EC-334
P0340 CAM PS/CIRC (PHS) EC-342
P0420 TW CATALYST SYS-B1 EC-347
P0430 TW CATALYST SYS-B2 EC-347
P0440 EVAP SMALL LEAK EC-352
P0443 PURG VOLUME CONT/V EC-367
P0446 VENT CONTROL VALVE EC-374
P0450 EVAP SYS PRES SEN EC-381
P0455 EVAP GROSS LEAK EC-394
P0460 FUEL LV SE (SLOSH) EC-407
P0461 FUEL LEVEL SENSOR EC-411
P0464 FUEL LEVL SEN/CIRC EC-413
P0500 VEH SPEED SEN/CIRC*4 EC-417
P0505 IACV/AAC VLV/CIRC EC-422
P0510 CLOSED TP SW/CIRC EC-431
P0600*2 A/T COMM LINE EC-440
P0605 ECMEC-444
P0705 PNP SW/CIRC AT-111
P0710 ATF TEMP SEN/CIRC AT-116
P0720 VEH SPD SEN/CIR A/T*4 AT-124
P0725 ENGINE SPEED SIG AT-130
P0731 A/T 1ST GR FNCTN AT-136
P0732 A/T 2ND GR FNCTN AT-143
P0733 A/T 3RD GR FNCTN AT-151
P0734 A/T 4TH GR FNCTN AT-157
P0740 TCC SOLENOID/CIRC AT-165
P0744 A/T TCC S/V FNCTN AT-170
P0745 L/PRESS SOL/CIRC AT-174
TROUBLE DIAGNOSIS Ð INDEX
Alphabetical & P No. Index for DTC (Cont'd)
EC-12

Supplemental Restraint System (SRS) ªAIR
BAGº and ªSEAT BELT PRE-TENSIONERº
NBEC0002The Supplemental Restraint System such as ªAIR BAGº and ªSEAT BELT PRE-TENSIONERº used along with
a seat belt, helps to reduce the risk or severity of injury to the driver and front passenger for certain types of
collision. The SRS system composition which is available to INFINITI QX4 is as follows:
IFor a frontal collision
The Supplemental Restraint System consists of driver air bag module (located in the center of the steer-
ing wheel), front passenger air bag module (located on the instrument panel on passenger side), seat belt
pre-tensioners, a diagnosis sensor unit, warning lamp, wiring harness and spiral cable.
IFor a side collision
The Supplemental Restraint System consists of front side air bag module (located in the outer side of front
seat), satellite sensor, diagnosis sensor unit (one of components of air bags for a frontal collision), wiring
harness, warning lamp (one of components of air bags for a frontal collision).
Information necessary to service the system safely is included in theRS sectionof this Service Manual.
WARNING:
ITo avoid rendering the SRS inoperative, which could increase the risk of personal injury or death
in the event of a collision which would result in air bag inflation, all maintenance must be performed
by an authorized INFINITI dealer.
IImproper maintenance, including incorrect removal and installation of the SRS, can lead to per-
sonal injury caused by unintentional activation of the system. For removal of Spiral Cable and Air
Bag Module, see the RS section.
IDo not use electrical test equipment on any circuit related to the SRS unless instructed to in this
Service Manual. Spiral cable and wiring harnesses covered with yellow insulation tape either just
before the harness connectors or for the complete harness are related to the SRS.
Precautions for On Board Diagnostic (OBD)
System of Engine and A/T
NBEC0003The ECM has an on board diagnostic system. It will light up the malfunction indicator lamp (MIL) to warn the
driver of a malfunction causing emission deterioration.
CAUTION:
IBe sure to turn the ignition switch OFF and disconnect the negative battery terminal before any
repair or inspection work. The open/short circuit of related switches, sensors, solenoid valves, etc.
will cause the MIL to light up.
IBe sure to connect and lock the connectors securely after work. A loose (unlocked) connector will
cause the MIL to light up due to the open circuit. (Be sure the connector is free from water, grease,
dirt, bent terminals, etc.)
ICertain systems and components, especially those related to OBD, may use a new style slide-
locking type harness connector. For description and how to disconnect, refer to EL-6, ªHARNESS
CONNECTOR (SLIDE-LOCKING TYPE)º.
IBe sure to route and secure the harnesses properly after work. The interference of the harness with
a bracket, etc. may cause the MIL to light up due to the short circuit.
IBe sure to connect rubber tubes properly after work. A misconnected or disconnected rubber tube
may cause the MIL to light up due to the malfunction of the fuel injection system, etc.
IBe sure to erase the unnecessary malfunction information (repairs completed) from the ECM and
TCM (Transmission control module) before returning the vehicle to the customer.
PRECAUTIONS
Supplemental Restraint System (SRS) ªAIR BAGº and ªSEAT BELT PRE-TENSIONERº
EC-14

Engine Fuel & Emission Control SystemNBEC0004
SEF952RE
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PRECAUTIONS
Engine Fuel & Emission Control System
EC-15

Tool name
(Kent-Moore No.)Description
Socket wrench
NT705
Removing and installing engine coolant tempera-
ture sensor
Oxygen sensor thread
cleaner
(J-43897-18)
(J-43897-12)
NT828
Reconditioning the exhaust system threads before
installing a new oxygen sensor. Use with anti-seize
lubricant shown below.
a: J-43897-18 18 mm diameter with pitch 1.5
mm, for Zirconia Oxygen Sensor
b: J-43897-12 12 mm diameter with pitch 1.25
mm, for Titania Oxygen Sensor
Anti-seize lubricant
(Permatex
TM133AR or
equivalent meeting MIL
specification MIL-A-907)
NT779
Lubricating oxygen sensor thread cleaning tool
when reconditioning exhaust system threads.
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PREPARATION
Commercial Service Tools (Cont'd)
EC-19

Engine Control Component Parts LocationNBEC0009
SEF929Y
ENGINE AND EMISSION CONTROL OVERALL SYSTEM
Engine Control Component Parts Location
EC-20