Engine control INFINITI QX4 2001 Factory Repair Manual

SBR665E
CONSULT-II Inspection Procedure=NBBR0097SELF-DIAGNOSIS PROCEDURENBBR0097S011. Turn ignition switch OFF.
2. Connect CONSULT-II to data link connector.
3. Start engine.
4. Drive vehicle over 30 km/h (19 MPH) for at least one minute.
PBR455D
5. Stop vehicle with engine running and touch ªSTARTº on CON-
SULT-II screen.
SBR670E
6. Touch ªABSº.
SBR636E
7. Touch ªSELF-DIAG RESULTSº.
IThe screen shows the detected malfunction and how many
times the ignition switch has been turned ON since the mal-
function.
8. Make the necessary repairs following the diagnostic proce-
dures.
PBR950C
9. After the malfunctions are repaired, erase the self-diagnostic
results stored in the control unit by touching ªERASEº.
10. Check warning lamp for deactivation after driving vehicle over
30 km/h (19 MPH) for at least one minute.
11. Test the ABS in a safe area to verify that it functions properly.
NOTE:
ªSELF-DIAG RESULTSº screen shows the detected malfunction
and how many times the ignition switch has been turned since the
malfunction.
ON BOARD DIAGNOSTIC SYSTEM DESCRIPTIONABS
CONSULT-II Inspection Procedure
BR-44

DATA MONITOR MODENBBR0097S05
MONITOR ITEM CONDITION SPECIFICATION
FR RH SENSOR
FR LH SENSOR
RR RH SENSOR
RR LH SENSORDrive vehicle.
(Each wheel is rotating.)Wheel speed signal
(Almost the same speed as speedometer.)
STOP LAMP SW Brake is depressed.Depress the pedal: ON
Release the pedal: OFF
G-SWITCHHVehicle is driven.
Vehicle is stopped.
Brake is applied.During sudden braking while driving on high  roads (asphalt
roads, etc.): OFF
While vehicle is stopped or during constant-speed driving: ON
FR RH IN SOL
FR RH OUT SOL
FR LH IN SOL
FR LH OUT SOL
RR IN SOL
RR OUT SOL1. Drive vehicle at speeds
over 30 km/h (19 MPH) for at
least 1 minute.
2. Engine is running.Operating conditions for each solenoid valve are indicated. ABS
is not operating: OFF
MOTOR RELAYABS is not operating: OFF
ABS is operating: ON
ACTUATOR RELAY
Ignition switch is ON or
engine is running.Ignition switch ON (Engine stops): OFF
Engine running: ON
WARNING LAMPABS warning lamp is turned on: ON
ABS warning lamp is turned off: OFF
BATTERY VOLT Power supply voltage for control unit
ABS OPER SIGABS is not operating: OFF
ABS is operating: ON
H: 4WD model only
ACTIVE TEST MODENBBR0097S06
TEST ITEM CONDITION JUDGEMENT
FR RH SOLENOID
FR LH SOLENOID
RR SOLENOID
Engine is running.Brake fluid pressure control operation
IN SOL OUT SOL
UP (Increase): OFF OFF
KEEP (Hold): ON OFF
DOWN (Decrease): ON ON
ABS MOTORABS actuator motor
ON: Motor runs (ABS motor relay ON)
OFF: Motor stops (ABS motor relay OFF)
ABS OPER SIGIgnition switch is ON or
engine is running.ON: Set ABS OPER SIG ªONº (ABS is operating.)
OFF: Set ABS OPER SIG ªOFFº (ABS is not operating.)
G SWITCHHIgnition switch is ON.G SWITCH (G SENSOR)
ON: Set G SWITCH MONITOR ªONº (G switch circuit is
closed.)
OFF: Set G SWITCH MONITOR ªOFFº (G switch circuit is
open.)
H: 4WD models only
NOTE:
Active test will automatically stop ten seconds after the test starts. (TEST IS STOPPED monitor shows ON.)
ON BOARD DIAGNOSTIC SYSTEM DESCRIPTIONABS
CONSULT-II Inspection Procedure (Cont'd)
BR-48

General SpecificationsNBBR0118Unit: mm (in)
Applied model2WD 4WD
Front brakeBrake model AD31VC
Cylinder bore diameter´number of pistons 44.45 (1.7500)´2
Pad
Length´width´thickness132.0´52.5´11
(5.20´2.067´0.43)
Rotor outer diameter´thickness 300´28 (11.81´1.10)
Rear brakeBrake model LT30C
Cylinder bore diameter 22.23 (7/8)
Lining length´width´thickness296´50´6.1
(11.65´1.97´0.240)
Drum inner diameter 295.0 (11.61)
Master cylinder Bore diameter 25.40 (1)
Control valveValve modelProportioning valve
within master cylinderLinkage type load
sensing valve
Split point
kPa (kg/cm
2, psi)´reducing ratio2,942 (30, 427)´0.2 (Variable)´0.18
Brake boosterBooster model M235T
Diaphragm diameterPri: 252 (9.92)
Sec: 205 (8.07)
Recommended brake fluidDOT 3
Disc BrakeNBBR0119Unit: mm (in)
Brake modelAD31VC
Pad wear limit Minimum thickness 2.0 (0.079)
Rotor repair limit Minimum thickness 26.0 (1.024)
Drum BrakeNBBR0120Unit: mm (in)
Brake modelLT30C
Lining wear limit Minimum thickness 1.5 (0.059)
Drum repair limitMaximum inner diameter 296.5 (11.67)
Out-of-round limit 0.03 (0.0012)
Brake PedalNBBR0121Unit: mm (in)
TransmissionA/T
Free height ªHº*175 - 185
(6.89 - 7.28)
Depressed height ªDº*
[under force of 490 N (50 kg, 110 lb) with engine running]70 (2.76)
Clearance ªCº between pedal stopper and threaded end of stop lamp switch or ASCD switch 0.3 - 1.0 (0.012 - 0.039)
Pedal free playAt clevis 1.0 - 3.0 (0.039 - 0.118)
At pedal pad1 - 3 (0.04 - 0.12)
*: Measured from surface of metal panel to pedal pad
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SERVICE DATA AND SPECIFICATIONS (SDS)
General Specifications
BR-83

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 ........................................................................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)
EC-7

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

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

SEF034Z
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ENGINE AND EMISSION CONTROL OVERALL SYSTEM
Engine Control Component Parts Location (Cont'd)
EC-21