Infiniti QX4 (R50). Manual — part 133

Measurement Points

NBBT0021S0202

SBT361

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BODY (ALIGNMENT)

Alignment (Cont’d)

BT-61

NOTES

ENGINE CONTROL SYSTEM

SECTION

EC

CONTENTS

TROUBLE DIAGNOSIS - INDEX . . . . . . . . . 8

Alphabetical & P No. Index for DTC . . . . . . ...8

PRECAUTIONS . . . . . . . . . . . . . . . .14

Supplemental Restraint System (SRS)

″

AIR

BAG

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and

″

SEAT BELT PRE-TENSIONER

″

. . . .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 . . . . . . . . . . ...57

ON 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 . . . . . . . . . . . ..190

DTC 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