2001 NISSAN X-TRAIL sensor oxygen

EC-14
Component Inspection .........................................1097
Removal and Installation .....................................1098
REFRIGERANT PRESSURE SENSOR .................1099
Component Description .......................................1099
ECM Terminals and Reference Value ..................1099
Wiring Diagram ....................................................11 0 0
Diagnostic Procedure ..........................................11 0 1
Removal and Installation .....................................11 0 2
ELECTRICAL LOAD SIGNAL ...............................110 3
CONSULT-II Reference Value in Data Monitor Mode
11 0 3
ECM Terminals and Reference Value ..................11 0 3
Wiring Diagram ....................................................11 0 4
Diagnostic Procedure ..........................................11 0 6
DATA LINK CONNECTOR .....................................1111
Wiring Diagram ....................................................1111
EVAPORATIVE EMISSION SYSTEM ....................111 2
Description ...........................................................111 2
Component Inspection .........................................111 4
POSITIVE CRANKCASE VENTILATION ..............111 5
Description ...........................................................111 5
Component Inspection .........................................111 5
SERVICE DATA AND SPECIFICATIONS (SDS) ...111 7
Fuel Pressure ......................................................111 7
Idle Speed and Ignition Timing ............................111 7
Calculated Load Value .........................................111 7
Mass Air Flow Sensor ..........................................111 7
Intake Air Temperature Sensor ............................111 7
Engine Coolant Temperature Sensor ..................111 7
Heated Oxygen Sensor 1 Heater ........................111 7
Heated Oxygen sensor 2 Heater .........................111 7
Crankshaft Position Sensor (POS) ......................111 7
Camshaft Position Sensor (PHASE) ...................111 7
Throttle Control Motor ..........................................111 8
Injector .................................................................111 8
Fuel Pump ...........................................................111 8
QR20(WITHOUT EURO-OBD)
INDEX FOR DTC ....................................................111 9
Alphabetical Index ...............................................111 9
DTC No. Index .....................................................11 2 0
PRECAUTIONS ......................................................112 1
Precautions for Supplemental Restraint System
(SRS) “AIR BAG” and “SEAT BELT PRE-TEN-
SIONER” ..............................................................11 2 1
On Board Diagnostic (OBD) System of Engine and
A/T .......................................................................11 2 1
Precaution ...........................................................11 2 1
Wiring Diagrams and Trouble Diagnosis .............11 2 4
PREPARATION ......................................................112 5
Special Service Tools .......................................... 11 2 5
Commercial Service Tools ...................................11 2 5
ENGINE CONTROL SYSTEM ...............................112 7
System Diagram ..................................................11 2 7
Vacuum Hose Drawing ........................................11 2 8
System Chart .......................................................11 2 9
Multiport Fuel Injection (MFI) System ..................11 2 9
Electronic Ignition (EI) System ............................11 3 2Air Conditioning Cut Control ................................11 3 2
Fuel Cut Control (at No Load and High Engine
Speed) .................................................................11 3 3
CAN Communication ...........................................11 3 3
BASIC SERVICE PROCEDURE ............................11 35
Idle Speed and Ignition Timing Check .................11 3 5
Accelerator Pedal Released Position Learning ....11 3 6
Throttle Valve Closed Position Learning ..............11 3 6
Idle Air Volume Learning ......................................11 3 7
Fuel Pressure Check ...........................................11 3 9
ON BOARD DIAGNOSTIC (OBD) SYSTEM ..........11 41
Introduction ..........................................................11 4 1
Two Trip Detection Logic ......................................11 4 1
Emission-related Diagnostic Information .............11 4 1
NATS (Nissan Anti-theft System) .........................11 4 3
Malfunction Indicator (MI) ....................................11 4 4
TROUBLE DIAGNOSIS .........................................11 47
Trouble Diagnosis Introduction ............................11 4 7
DTC Inspection Priority Chart ..............................11 5 0
Fail-safe Chart .....................................................11 5 1
Basic Inspection ...................................................11 5 2
Symptom Matrix Chart .........................................11 5 6
Engine Control Component Parts Location ..........11 6 0
Circuit Diagram ....................................................11 6 4
ECM Harness Connector Terminal Layout ...........11 6 6
ECM Terminals and Reference Value ..................11 6 6
CONSULT-II Function ..........................................
11 7 3
CONSULT-II Reference Value in Data Monitor ....11 8 2
Major Sensor Reference Graph in Data Monitor
Mode ....................................................................11 8 5
TROUBLE DIAGNOSIS - SPECIFICATION VALUE 11 88
Description ...........................................................11 8 8
Testing Condition .................................................11 8 8
Inspection Procedure ........................................... 11 8 8
Diagnostic Procedure ........................................... 11 8 9
TROUBLE DIAGNOSIS FOR INTERMITTENT INCI-
DENT ......................................................................11 92
Description ...........................................................11 9 2
Diagnostic Procedure ........................................... 11 9 2
POWER SUPPLY CIRCUIT FOR ECM ..................11 93
Wiring Diagram ....................................................11 9 3
ECM Terminals and Reference Value ..................11 9 4
Diagnostic Procedure ........................................... 11 9 4
Component Inspection .........................................11 9 8
DTC U1000 CAN COMMUNICATION LINE ...........11 99
Description ...........................................................11 9 9
On Board Diagnosis Logic ...................................11 9 9
DTC Confirmation Procedure ...............................11 9 9
Wiring Diagram ....................................................1200
Diagnostic Procedure ........................................... 1201
DTC P0102, P0103 MAF SENSOR ........................1202
Component Description .......................................1202
CONSULT-II Reference Value in Data Monitor Mode
1202
ECM Terminals and Reference Value ..................1202
On Board Diagnosis Logic ...................................1203
DTC Confirmation Procedure ...............................1203
Wiring Diagram ....................................................1205
Diagnostic Procedure ........................................... 1206

EC-17
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ECA INJECTOR CIRCUIT ..............................................1357
Component Description .......................................1357
CONSULT-II Reference Value in Data Monitor Mode
1357
ECM Terminals and Reference Value .................1357
Wiring Diagram ...................................................1358
Diagnostic Procedure ..........................................1359
Component Inspection ........................................1361
Removal and Installation .....................................1361
START SIGNAL .....................................................1362
CONSULT-II Reference Value in Data Monitor Mode
1362
ECM Terminals and Reference Value .................1362
Wiring Diagram ...................................................1363
Diagnostic Procedure ..........................................1364
FUEL PUMP CIRCUIT ...........................................1366
Description ..........................................................1366
CONSULT-II Reference Value in Data Monitor Mode
1366
ECM Terminals and Reference Value .................1366
Wiring Diagram ...................................................1368
Diagnostic Procedure ..........................................1369
Component Inspection ........................................1371
Removal and Installation .....................................1372
REFRIGERANT PRESSURE SENSOR ................1373
Component Description .......................................1373
ECM Terminals and Reference Value .................1373
Wiring Diagram ...................................................1374
Diagnostic Procedure ..........................................1375
Removal and Installation .....................................1376
ELECTRICAL LOAD SIGNAL ...............................1377
CONSULT-II Reference Value in Data Monitor Mode
1377
ECM Terminals and Reference Value .................1377
Wiring Diagram ...................................................1378
Diagnostic Procedure ..........................................1380
DATA LINK CONNECTOR ....................................1385
Wiring Diagram ...................................................1385
EVAPORATIVE EMISSION SYSTEM ....................1386
Description ..........................................................1386
Component Inspection ........................................1388
POSITIVE CRANKCASE VENTILATION ..............1389
Description ..........................................................1389
Component Inspection ........................................1389
SERVICE DATA AND SPECIFICATIONS (SDS) ...1391
Fuel Pressure ......................................................1391
Idle Speed and Ignition Timing ............................1391
Calculated Load Value ........................................1391
Mass Air Flow Sensor .........................................1391
Intake Air Temperature Sensor ...........................1391
Engine Coolant Temperature Sensor ..................1391
Heated Oxygen Sensor 1 Heater ........................1391
Heated Oxygen sensor 2 Heater .........................1391
Crankshaft Position Sensor (POS) ......................1391
Camshaft Position Sensor (PHASE) ...................1391
Throttle Control Motor ......................................... 1392
Injector ................................................................1392
Fuel Pump ...........................................................1392
YD
INDEX FOR DTC ....................................................1393
Alphabetical Index ...............................................1393
DTC No. Index .....................................................1393
PRECAUTIONS .....................................................1395
Precautions for Supplemental Restraint System
(SRS) “AIR BAG” and “SEAT BELT PRE-TEN-
SIONER” ..............................................................1395
Precautions ..........................................................1395
Wiring Diagrams and Trouble Diagnosis .............1397
ENGINE CONTROL SYSTEM ...............................1398
System Diagram ..................................................1398
System Chart .......................................................1399
Fuel Injection Control System ..............................1399
Fuel Injection Timing Control System ..................1401
Air Conditioning Cut Control ................................1401
F u e l C u t C o n t r o l ( A t N o L o a d & H i g h E n g i n e S p e e d ) 1401
Crankcase Ventilation System .............................1402
CAN Communication ...........................................1402
BASIC SERVICE PROCEDURE ............................1404
Fuel Filter .............................................................1404
Accelerator Pedal Released Position Learning ...1404
Fuel Pressure Relief Valve ..................................1405
ON BOARD DIAGNOSTIC (OBD) SYSTEM .........1406
DTC and MI Detection Logic ...............................1406
Diagnostic Trouble Code (DTC) ..........................1406
NATS (Nissan Anti-theft System) ........................1406
Malfunction Indicator (MI) ....................................1407
TROUBLE DIAGNOSIS .........................................1409
Trouble Diagnosis Introduction ............................1409
Basic Inspection ..................................................1412
Symptom Matrix Chart .........................................1416
Engine Control Component Parts Location .........1420
Circuit Diagram ....................................................1423
ECM Harness Connector Terminal Layout ..........1425
ECM Terminals And Reference Value .................1425
CONSULT-II Function ..........................................1431
CONSULT-II Reference Value in Data Monitor Mode
1437
Major Sensor Reference Graph in Data Monitor
Mode ....................................................................1440
TROUBLE DIAGNOSIS FOR INTERMITTENT INCI-
DENT ......................................................................1441
Description ...........................................................1441
Diagnostic Procedure ..........................................1441
POWER SUPPLY CIRCUIT FOR ECM ..................1442
ECM Terminals and Reference Value ..................1442
Wiring Diagram ....................................................1443
Diagnostic Procedure ..........................................1444
Component Inspection .........................................1447
DTC U1000 CAN COMMUNICATION LINE ...........1448
Description ...........................................................1448
On Board Diagnosis Logic ...................................1448
DTC Confirmation Procedure ..............................1448
Wiring Diagram ....................................................1449
Diagnostic Procedure ..........................................1450
DTC P0100 MASS AIR FLOW SENSOR (MAFS) .1451
Component Description .......................................1451

PREPARATION
EC-29
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PREPARATIONPFP:00002
Special Service ToolsEBS00M07
The actual shapes of Kent-Moore tools may differ from those of special service tools illustrated here.
Commercial Service ToolsEBS00M08
Tool number
Tool nameDescription
KV10117100
Heated oxygen
sensor wrenchLoosening or tightening heated oxygen sensors
with 22 mm (0.87 in) hexagon nut
KV10114400
Heated oxygen
sensor wrenchLoosening or tightening heated oxygen sensors
a: 22 mm (0.87 in)
S-NT379
S-NT636
Tool name Description
Quick connector
releaseRemoving fuel tube quick connectors in engine
room
(Available in SEC. 164 of PARTS CATALOG:
Part No. 16441 6N210)
Fuel filler cap adapter Checking fuel tank vacuum relief valve opening
pressure
Socket wrench Removing and installing engine coolant
temperature sensor
PBIC0198E
S-NT653
S-NT705

EC-30
[QR25(WITH EURO-OBD)]
PREPARATION
Oxygen sensor thread
cleanerReconditioning 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
Zirconia Oxygen Sensor
b: 12 mm diameter with pitch 1.25 mm for
Titania Oxygen Sensor
Anti-seize lubricant
i.e.: (Permatex
TM
133AR or equivalent
meeting MIL
specification MIL-A-
907)Lubricating oxygen sensor thread cleaning tool
when reconditioning exhaust system threads. Tool name Description
AEM488
S-NT779

ENGINE CONTROL SYSTEM
EC-33
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System ChartEBS00M0B
*1: This sensor is not used to control the engine system under normal conditions.
*2: These signals are sent to the ECM through CAN communication line.
Multiport Fuel Injection (MFI) SystemEBS00M0C
INPUT/OUTPUT SIGNAL CHART
*1: Under normal conditions, this sensor is not for engine control operation.
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
Input (Sensor) ECM Function Output (Actuator)
●Camshaft position sensor (PHASE)
●Crankshaft position sensor (POS)
●Mass air flow sensor
●Engine coolant temperature sensor
●Heated oxygen 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
●Heated oxygen sensor 2 *1
●TCM (Transmission control module) *2
●Wheel sensor
●Air conditioner switch
●Electrical loadFuel injection & mixture ratio control Fuel injectors
Electronic ignition system Power transistors
Fuel pump control Fuel pump relay
On board diagnostic system MI (On the instrument panel)
Heated oxygen sensor 1 heater control Heated oxygen sensor 1 heater
Heated oxygen sensor 2 heater control Heated oxygen sensor 2 heater
Power valve control VIAS control solenoid valve
EVAP canister purge flow controlEVAP canister purge volume control
solenoid valve
Air conditioning cut control Air conditioner relay
Cooling fan control Cooling fan relays
Sensor Input Signal to ECMECM func-
tionActuator
Crankshaft position sensor (POS)
Engine speed
Piston position
Fuel injec-
tion & mix-
ture ratio
controlFuel injectors Camshaft position sensor (PHASE)
Mass air flow sensor Amount of intake air
Engine coolant temperature sensor Engine coolant temperature
Heated oxygen 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
Ignition switch Start signal
Knock sensor Engine knocking condition
Battery Battery voltage
Power steering pressure sensor Power steering operation
Heated oxygen sensor 2 *
1Density of oxygen in exhaust gas
Wheel sensor Vehicle speed
Air conditioner switch Air conditioner operation

EC-34
[QR25(WITH EURO-OBD)]
ENGINE CONTROL SYSTEM
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
MIXTURE RATIO FEEDBACK CONTROL (CLOSED LOOP CONTROL)
The mixture ratio feedback system provides the best air-fuel mixture ratio for driveability and emission control.
The three way catalyst (manifold) can then better reduce CO, HC and NOx emissions. This system uses
heated oxygen sensor 1 in the exhaust manifold to monitor if the engine operation is rich or lean. The ECM
adjusts the injection pulse width according to the sensor voltage signal. For more information about heated
oxygen sensor 1, refer to EC-163
. This maintains the mixture ratio within the range of stoichiometric (ideal air-
fuel mixture).
This stage is referred to as the closed loop control condition.
Heated oxygen sensor 2 is located downstream of the three way catalyst (manifold). Even if the switching
characteristics of heated oxygen sensor 1 shift, the air-fuel ratio is controlled to stoichiometric by the signal
from heated oxygen sensor 2.
Open Loop Control
The open loop system condition refers to when the ECM detects any of the following conditions. Feedback
control stops in order to maintain stabilized fuel combustion.
●Deceleration and acceleration
●High-load, high-speed operation
●Malfunction of heated oxygen sensor 1 or its circuit
●Insufficient activation of heated oxygen sensor 1 at low engine coolant temperature
●High engine coolant temperature
●During warm-up
●After shifting from “N” to “D”
●When starting the engine
MIXTURE RATIO SELF-LEARNING CONTROL
The mixture ratio feedback control system monitors the mixture ratio signal transmitted from heated oxygen
sensor 1. This feedback signal is then sent to the ECM. The ECM controls the basic mixture ratio as close to
the theoretical mixture ratio as possible. However, the basic mixture ratio is not necessarily controlled as orig-
PBIB0121E

ENGINE CONTROL SYSTEM
EC-35
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inally designed. Both manufacturing differences (i.e., mass air flow sensor hot film) and characteristic changes
during operation (i.e., injector clogging) directly affect mixture ratio.
Accordingly, the difference between the basic and theoretical mixture ratios is monitored in this system. This is
then computed in terms of “injection pulse duration” to automatically compensate for the difference between
the two ratios.
“Fuel trim” refers to the feedback compensation value compared against the basic injection duration. Fuel trim
includes short term fuel trim and long term fuel trim.
“Short term fuel trim” is the short-term fuel compensation used to maintain the mixture ratio at its theoretical
value. The signal from heated oxygen sensor 1 indicates whether the mixture ratio is RICH or LEAN compared
to the theoretical value. The signal then triggers a reduction in fuel volume if the mixture ratio is rich, and an
increase in fuel volume if it is lean.
“Long term fuel trim” is overall fuel compensation carried out long-term to compensate for continual deviation
of the short term fuel trim from the central value. Such deviation will occur due to individual engine differences,
wear over time and changes in the usage environment.
FUEL INJECTION TIMING
Two types of systems are used.
Sequential Multiport Fuel Injection System
Fuel is injected into each cylinder during each engine cycle according to the firing order. This system is used
when the engine is running.
Simultaneous Multiport Fuel Injection System
Fuel is injected simultaneously into all four cylinders twice each engine cycle. In other words, pulse signals of
the same width are simultaneously transmitted from the ECM.
The four injectors will then receive the signals two times for each engine cycle.
This system is used when the engine is being started and/or if the fail-safe system (CPU) is operating.
FUEL SHUT-OFF
Fuel to each cylinder is cut off during deceleration or operation of the engine at excessively high speeds.
Electronic Ignition (EI) SystemEBS00M0D
INPUT/OUTPUT SIGNAL CHART
SEF337W
Sensor Input Signal to ECMECM func-
tionActuator
Crankshaft position sensor (POS)
Engine speed
Piston position
Ignition
timing con-
trolPower transistor Camshaft position sensor (PHASE)
Mass air flow sensor Amount of intake air
Engine coolant temperature sensor Engine coolant temperature
Throttle position sensor Throttle position
Accelerator pedal position sensor Accelerator pedal position
Ignition switch Start signal
Knock sensor Engine knocking
Park/neutral position (PNP) switch Gear position
Battery Battery voltage
Wheel sensor Vehicle speed

EC-50
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ON BOARD DIAGNOSTIC (OBD) SYSTEM
SRT Item
The table below shows required self-diagnostic items to set the SRT to “CMPLT”.
*1: If completion of several SRTs is required, perform driving patterns (DTC confirmation procedure), one by one based on the priority for
models with CONSULT-II.
SRT Set Timing
SRT is set as “CMPLT” after self-diagnosis has been performed one or more times. Completion of SRT is
done regardless of whether the result is OK or NG. The set timing is different between OK and NG results and
is shown in the table below.
OK: Self-diagnosis is carried out and the result is OK.
NG: Self-diagnosis is carried out and the result is NG.
—: Self-diagnosis is not carried out.
When all SRT related self-diagnoses showed OK results in a single cycle (Ignition OFF-ON-OFF), the SRT will
indicate “CMPLT”. → Case 1 above
When all SRT related self-diagnoses showed OK results through several different cycles, the SRT will indicate
“CMPLT” at the time the respective self-diagnoses have at least one OK result. → Case 2 above
SRT item
(CONSULT-II
indication)Performance
Priority*1Required self-diagnostic items to set the SRT to “CMPLT” Corresponding DTC No.
CATALYST 2 Three way catalyst function P0420
HO2S 1 Heated oxygen sensor 1 P0132
Heated oxygen sensor 1 P0133
Heated oxygen sensor 1 P0134
Heated oxygen sensor 1 P1143
Heated oxygen sensor 1 P1144
Heated oxygen sensor 2 P0138
Heated oxygen sensor 2 P0139
Heated oxygen sensor 2 P1146
Heated oxygen sensor 2 P1147
HO2S HTR 1 Heated oxygen sensor 1 heater P0031, P0032
Heated oxygen sensor 2 heater P0037, P0038
Self-diagnosis resultExample
DiagnosisIgnition cycle
← ON → OFF ← ON → OFF ← ON → OFF ← ON →
All OK Case 1 P0400 OK (1) — (1) OK (2) — (2)
P0402 OK (1) — (1) — (1) OK (2)
P1402 OK (1) OK (2) — (2) — (2)
SRT of EGR “CMPLT” “CMPLT” “CMPLT” “CMPLT”
Case 2 P0400 OK (1) — (1) — (1) — (1)
P0402 — (0) — (0) OK (1) — (1)
P1402 OK (1) OK (2) — (2) — (2)
SRT of EGR “INCMP” “INCMP” “CMPLT” “CMPLT”
NG exists Case 3 P0400 OK OK — —
P0402 — — — —
P1402 NG — NGNG
(Consecutive
NG)
(1st trip)
DTC1st trip DTC — 1st trip DTCDTC
(= MI “ON”)
SRT of EGR “INCMP” “INCMP” “INCMP” “CMPLT”