2001 NISSAN X-TRAIL ECM

PRECAUTIONS
GI-5
C
D
E
F
G
H
I
J
K
L
MB
GI
●Use approved bonding agent, sealants or their equivalents when required.
●Use tools and recommended special tools where specified for safe and efficient service repairs.
●When repairing the fuel, oil, water, vacuum or exhaust systems, check all affected lines for leaks.
●Before servicing the vehicle:
Protect fenders, upholstery and carpeting with appropriate cov-
ers.
Take caution that keys, buckles or buttons do not scratch paint.
WARNING:
To prevent ECM from storing the diagnostic trouble codes, do not carelessly disconnect the harness
connectors which are related to the engine control system and TCM (transmission control module)
system. The connectors should be disconnected only when working according to the WORK FLOW of
TROUBLE DIAGNOSES in EC and AT sections.
Precautions for All Mode 4 × 4 SystemEAS000GQ
Even if the 2WD mode is selected, the All mode 4 × 4 system occasionally changes from 2WD to 4WD auto-
matically depending on the driving conditions.
When spinning the front wheels by running the engine with the front wheels jacked up or mounted on the free
rollers / or a chassis dynamometer, be careful because the vehicle may suddenly move due to the driving
force from the rear wheels.
To avoid personal injury and vehicle damage, use one of the following methods when working with the front
wheels drive force and spinning freely.
● Remove the propeller shaft.
● Use free rollers / chassis dynamometer designed for 4WD vehicles.
Precautions for Three Way CatalystEAS000FR
If a large amount of unburned fuel flows into the catalyst, the catalyst temperature will be excessively high. To
prevent this, follow the instructions.
●Use unleaded gasoline only. Leaded gasoline will seriously damage the three way catalyst.
●When checking for ignition spark or measuring engine compression, make tests quickly and only when
necessary.
●Do not run engine when the fuel tank level is low, otherwise the engine may misfire, causing damage to
the catalyst.
Do not place the vehicle on flammable material. Keep flammable material off the exhaust pipe and the three
way catalyst.
Precautions for FuelEAS000P9
GASOLINE ENGINE
Use unleaded gasoline with an octane rating of at least 95 (RON).
CAUTION:
Do not use leaded gasoline. Using leaded gasoline will damage the three way catalyst. Using a fuel
other than that specified could adversely affect the emission control devices and systems, and could
also affect the warranty coverage validity.
DIESEL ENGINE
Diesel fuel of at least 50 cetane.
If two types of diesel fuel are available, use summer or winter fuel properly according to the following temper-
ature conditions.
●Above –7°C (20°F) ... Summer type diesel fuel.
●Below –7°C (20°F) ... Winter type diesel fuel.
SGI234

GI-6
PRECAUTIONS
CAUTION:
●Do not use home heating oil, gasoline or other alternate fuels in your diesel engine. The use of
those can cause engine damage.
●Do not use summer fuel at temperatures below –7°C (20°F). The cold temperatures will cause wax
to form in the fuel. As a result, it may prevent the engine from running smoothly.
●Do not add gasoline or other alternate fuels to diesel fuel.
Precautions for Multiport Fuel Injection System or Engine Control SystemEAS000FT
●Before connecting or disconnecting any harness connector for
the multiport fuel injection system or ECM:
Turn ignition switch to “OFF” position.
Disconnect negative battery terminal.
Otherwise, there may be damage to ECM.
●Before disconnecting pressurized fuel line from fuel pump to
injectors, be sure to release fuel pressure.
●Be careful not to jar components such as ECM and mass air
flow sensor.
Precautions for Turbocharger (If Equipped)EAS000FU
The turbocharger turbine revolves at extremely high speeds and
becomes very hot. Therefore, it is essential to maintain a clean sup-
ply of oil flowing through the turbocharger and to follow all required
maintenance instructions and operating procedures.
●Always use the recommended oil. Follow the instructions for
proper time to change the oil and proper oil level.
●Avoid accelerating engine to a high rpm immediately after start-
ing.
●If engine had been operating at high rpm for an extended period
of time, let it idle for a few minutes prior to shutting if off.
Precautions for HosesEAS000FV
HOSE REMOVAL AND INSTALLATION
●To prevent damage to rubber hose, do not pry off rubber hose
with tapered tool or screwdriver.
●To reinstall the rubber hose securely, make sure that hose inser-
tion length and orientation is correct. (If tube is equipped with
hose stopper, insert rubber hose into tube until it butts up
against hose stopper.)
SGI787
SGI292
SMA019D
SMA020D

HOW TO USE THIS MANUAL
GI-13
C
D
E
F
G
H
I
J
K
L
MB
GITurn ignition switch from “OFF” to
“ON” position.Drive vehicle.
Turn ignition switch from “ON” to
“OFF” position.Disconnect battery negative cable.
Do not start engine, or check with
engine stopped.Depress brake pedal.
Start engine, or check with engine run-
ning.Release brake pedal.
Apply parking brake. Depress accelerator pedal.
Release parking brake. Release accelerator pedal.
Check after engine is warmed up suffi-
ciently.Pin terminal check for SMJ type ECM
and TCM connectors.
For details regarding the terminal
arrangement, refer to the “ELEC-
TRICAL UNITS” electrical reference
page at the end of the manual. Voltage should be measured with a
voltmeter.
Circuit resistance should be measured
with an ohmmeter.
Current should be measured with an
ammeter.
Procedure with CONSULT-II
Procedure without CONSULT-II Symbol Symbol explanation Symbol Symbol explanation

HOW TO USE THIS MANUAL
GI-19
C
D
E
F
G
H
I
J
K
L
MB
GI
Detectable Lines and Non-Detectable Lines
In some wiring diagrams, two kinds of lines, representing wires, with different weight are used.
●A line with regular weight (wider line) represents a “detectable
line for DTC (Diagnostic Trouble Code)”. A “detectable line for
DTC” is a circuit in which ECM can detect its malfunctions with
the on board diagnostic system.
●A line with less weight (thinner line) represents a “non-detect-
able line for DTC”. A “non-detectable line for DTC” is a circuit in
which ECM cannot detect its malfunctions with the on board
diagnostic system.
Multiple Switch
The continuity of multiple switch is described in two ways as shown below.
●The switch chart is used in schematic diagrams.
SGI862-B

CONSULT-II CHECKING SYSTEM
GI-33
C
D
E
F
G
H
I
J
K
L
MB
GI
CONSULT-II CHECKING SYSTEMPFP:00000
DescriptionEAS000G8
●CONSULT-II is a hand-held type tester. When it is connected with a diagnostic connector equipped on the
vehicle side, it will communicate with the control unit equipped in the vehicle and then enable various
kinds of diagnostic tests.
●Refer to “CONSULT-II Software Operation Manual” for more information.
Function and System Application EAS000G9
x:Applicable
*1: Nissan Anti-Theft System
Nickel Metal Hydride Battery Replacement EAS000GA
CONSULT-II contains a nickel metal hydride battery. When replacing the battery obey the following:
WARNING:
Replace the nickel metal hydride battery with Genuine CONSULT-II battery only. Use of another bat-
tery may present a risk of fire or explosion. The battery may present a fire or chemical burn hazard if
mistreated. Do not recharge, disassemble or dispose of in fire.
Keep the battery out of reach of children and discard used battery conforming to the local regulations.
Diagnostic test
modeFunction
ENGINE
A/T
AIR BAG
ABS
ABS (Including ESP)
ALL MODE 4WD
NATS*1
Work supportThis mode enables a technician to adjust some devices faster and more accu-
rately by following the indications on CONSULT-II.x- -- x- -
Self-diagnostic
resultsSelf-diagnostic results can be read and erased quickly. x x x x x x x
Trouble diagnos-
tic recordCurrent self-diagnostic results and all trouble diagnostic records previously
stored can be read.--x----
Data monitor Input/Output data in the ECM can be read. x x - x x x -
Active testDiagnostic Test Mode in which CONSULT-II drives some actuators apart from the
ECMs and also shifts some parameters in a specified range.x- -xx- -
DTC confirmationThe results of SRT (System Readiness Test) and the self-diagnosis status/result
can be confirmed.x------
DTC work sup-
portSelect the operating condition to confirm Diagnosis Trouble Codes. -x-----
ECM part number ECM part number can be read. x x - x x x -
ECU discrimi-
nated No.Classification number of a replacement ECU can be read to prevent an incorrect
ECU from being installed.--x----
Function testConducted by CONSULT-II instead of a technician to determine whether each
system is “OK” or “NG”.xxxxx - -
Control unit ini-
tializationAll registered ignition key IDs in NATS components can be initialized and new
IDs can be registered.------x
Self-function
checkECM checks its own NATS communication interface. - - - - - - x

TERMINOLOGY
GI-45
C
D
E
F
G
H
I
J
K
L
MB
GI
TERMINOLOGYPFP:00011
SAE J1930 Terminology List EAS000GH
All emission related terms used in this publication in accordance with SAE J1930 are listed. Accordingly, new
terms, new acronyms/abbreviations and old terms are listed in the following chart.
NEW TERMNEW ACRONYM /
ABBREVIATIONOLD TERM
Air cleaner ACL Air cleaner
Barometric pressure BARO ***
Barometric pressure sensor-BCDD BAROS-BCDD BCDD
Camshaft position CMP ***
Camshaft position sensor CMPS Crank angle sensor
Canister *** Canister
Carburetor CARB Carburetor
Charge air cooler CAC Intercooler
Closed loop CL Closed loop
Closed throttle position switch CTP switch Idle switch
Clutch pedal position switch CPP switch Clutch switch
Continuous fuel injection system CFI system ***
Continuous trap oxidizer system CTOX system ***
Crankshaft position CKP ***
Crankshaft position sensor CKPS ***
Data link connector DLC ***
Data link connector for CONSULT-II DLC for CONSULT-II Diagnostic connector for CONSULT-II
Diagnostic test mode DTM Diagnostic mode
Diagnostic test mode selector DTM selector Diagnostic mode selector
Diagnostic test mode I DTM I Mode I
Diagnostic test mode II DTM II Mode II
Diagnostic trouble code DTC Malfunction code
Direct fuel injection system DFI system ***
Distributor ignition system DI system Ignition timing control
Early fuel evaporation-mixture heater EFE-mixture heater Mixture heater
Early fuel evaporation system EFE system Mixture heater control
Electrically erasable programmable read
only memoryEEPROM ***
Electronic ignition system EI system Ignition timing control
Engine control EC ***
Engine control module ECM ECCS control unit
Engine coolant temperature ECT Engine temperature
Engine coolant temperature sensor ECTS Engine temperature sensor
Engine modification EM ***
Engine speed RPM Engine speed
Erasable programmable read only memory EPROM ***
Evaporative emission canister EVAP canister Canister
Evaporative emission system EVAP system Canister control solenoid valve
Exhaust gas recirculation valve EGR valve EGR valve

EC-1
ENGINE CONTROL SYSTEM
B ENGINE
CONTENTS
C
D
E
F
G
H
I
J
K
L
M
SECTION
A
EC
ENGINE CONTROL SYSTEM
QR25(WITH EURO-OBD)
INDEX FOR DTC ...................................................... 20
Alphabetical Index .................................................. 20
DTC No. Index ....................................................... 22
PRECAUTIONS ........................................................ 25
Precautions for Supplemental Restraint System
(SRS) “AIR BAG” and “SEAT BELT PRE-TEN-
SIONER” ................................................................ 25
On Board Diagnostic (OBD) System of Engine and
A/T .......................................................................... 25
Precaution .............................................................. 25
Wiring Diagrams and Trouble Diagnosis ................ 28
PREPARATION ......................................................... 29
Special Service Tools ............................................. 29
Commercial Service Tools ...................................... 29
ENGINE CONTROL SYSTEM .................................. 31
System Diagram ..................................................... 31
Vacuum Hose Drawing ........................................... 32
System Chart ......................................................... 33
Multiport Fuel Injection (MFI) System .................... 33
Electronic Ignition (EI) System ............................... 35
Air Conditioning Cut Control ................................... 36
Fuel Cut Control (at No Load and High Engine
Speed) .................................................................... 37
CAN Communication .............................................. 37
BASIC SERVICE PROCEDURE .............................. 38
Idle Speed and Ignition Timing Check .................... 38
Accelerator Pedal Released Position Learning ...... 39
Throttle Valve Closed Position Learning ................ 39
Idle Air Volume Learning ........................................ 39
Fuel Pressure Check .............................................. 42
ON BOARD DIAGNOSTIC (OBD) SYSTEM ............ 44
Introduction ............................................................ 44
Two Trip Detection Logic ........................................ 44
Emission-related Diagnostic Information ................ 45
NATS (Nissan Anti-theft System) ........................... 58
Malfunction Indicator (MI) ....................................... 58
OBD System Operation Chart ................................ 61
TROUBLE DIAGNOSIS ............................................ 67
Trouble Diagnosis Introduction ............................... 67DTC Inspection Priority Chart ................................. 70
Fail-safe Chart ........................................................ 71
Basic Inspection ..................................................... 73
Symptom Matrix Chart ............................................ 77
Engine Control Component Parts Location ............ 81
Circuit Diagram ....................................................... 85
ECM Harness Connector Terminal Layout ............. 87
ECM Terminals and Reference Value ..................
... 87
CONSULT-II Function ............................................. 94
Generic Scan Tool (GST) Function .......................104
CONSULT-II Reference Value in Data Monitor .....106
Major Sensor Reference Graph in Data Monitor
Mode .....................................................................109
TROUBLE DIAGNOSIS - SPECIFICATION VALUE ..111
Description .............................................................111
Testing Condition ...................................................111
Inspection Procedure .............................................111
Diagnostic Procedure ...........................................112
TROUBLE DIAGNOSIS FOR INTERMITTENT INCI-
DENT .......................................................................115
Description ............................................................115
Diagnostic Procedure ...........................................115
POWER SUPPLY CIRCUIT FOR ECM ...................116
Wiring Diagram .....................................................116
ECM Terminals and Reference Value ...................117
Diagnostic Procedure ...........................................117
Component Inspection ..........................................121
DTC U1000 CAN COMMUNICATION LINE ............122
Description ............................................................122
On Board Diagnosis Logic ....................................122
DTC Confirmation Procedure ...............................122
Wiring Diagram .....................................................123
Diagnostic Procedure ...........................................124
DTC P0011 IVT CONTROL .....................................125
Description ............................................................125
CONSULT-II Reference Value in Data Monitor Mode
.125
ECM Terminals and Reference Value ...................125
On Board Diagnosis Logic ....................................126

EC-2
DTC Confirmation Procedure ...............................126
Diagnostic Procedure ...........................................127
DTC P0031, P0032 HO2S1 HEATER .....................128
Description ............................................................128
CONSULT-II Reference Value in Data Monitor Mode
.128
ECM Terminals and Reference Value ...................128
On Board Diagnosis Logic ....................................129
DTC Confirmation Procedure ...............................129
Wiring Diagram .....................................................130
Diagnostic Procedure ...........................................131
Component Inspection ..........................................132
Removal and Installation ......................................132
DTC P0037, P0038 HO2S2 HEATER .....................133
Description ............................................................133
CONSULT-II Reference Value in Data Monitor Mode
.133
ECM Terminals and Reference Value ...................133
On Board Diagnosis Logic ....................................134
DTC Confirmation Procedure ...............................134
Wiring Diagram .....................................................135
Diagnostic Procedure ...........................................136
Component Inspection ..........................................137
Removal and Installation ......................................137
DTC P0102, P0103 MAF SENSOR .........................138
Component Description ........................................138
CONSULT-II Reference Value in Data Monitor Mode
.138
ECM Terminals and Reference Value ...................138
On Board Diagnosis Logic ....................................138
DTC Confirmation Procedure ...............................139
Wiring Diagram .....................................................140
Diagnostic Procedure ...........................................141
Component Inspection ..........................................142
Removal and Installation ......................................143
DTC P0112, P0113 IAT SENSOR ...........................144
Component Description ........................................144
On Board Diagnosis Logic ....................................144
DTC Confirmation Procedure ...............................144
Wiring Diagram .....................................................146
Diagnostic Procedure ...........................................147
Component Inspection ..........................................148
Removal and Installation ......................................148
DTC P0117, P0118 ECT SENSOR ..........................149
Component Description ........................................149
On Board Diagnosis Logic ....................................149
DTC Confirmation Procedure ...............................150
Wiring Diagram .....................................................151
Diagnostic Procedure ...........................................152
Component Inspection ..........................................153
Removal and Installation ......................................153
DTC P0122, P0123 TP SENSOR ............................154
Component Description ........................................154
CONSULT-II Reference Value in Data Monitor Mode
.154
On Board Diagnosis Logic ....................................154
DTC Confirmation Procedure ...............................154
Wiring Diagram .....................................................156
Diagnostic Procedure ...........................................157Component Inspection ..........................................159
Remove and Installation .......................................159
DTC P0127 IAT SENSOR ........................................160
Component Description ........................................160
On Board Diagnosis Logic ....................................160
DTC Confirmation Procedure ................................160
Diagnostic Procedure ............................................161
Component Inspection ..........................................161
Removal and Installation .......................................162
DTC P0132 HO2S1 ................................................ .163
Component Description ........................................163
CONSULT-II Reference Value in Data Monitor Mode
.163
ECM Terminals and Reference Value ...................163
On Board Diagnosis Logic ....................................164
DTC Confirmation Procedure ................................164
Wiring Diagram .....................................................165
Diagnostic Procedure ............................................166
Component Inspection ..........................................167
Removal and Installation .......................................168
DTC P0133 HO2S1 ................................................ .169
Component Description ........................................169
CONSULT-II Reference Value in Data Monitor Mode
.169
ECM Terminals and Reference Value ...................169
On Board Diagnosis Logic ....................................170
DTC Confirmation Procedure ................................170
Overall Function Check .........................................171
Wiring Diagram .....................................................172
Diagnostic Procedure ............................................173
Component Inspection ..........................................175
Removal and Installation .......................................177
DTC P0134 HO2S1 ................................................ .178
Component Description ........................................178
CONSULT-II Reference Value in Data Monitor Mode
.178
ECM Terminals and Reference Value ...................178
On Board Diagnosis Logic ....................................179
DTC Confirmation Procedure ................................179
Overall Function Check .........................................180
Wiring Diagram ....................................................
.181
Diagnostic Procedure ............................................182
Component Inspection ..........................................183
Removal and Installation .......................................184
DTC P0138 HO2S2 ................................................ .185
Component Description ........................................185
CONSULT-II Reference Value in Data Monitor Mode
.185
ECM Terminals and Reference Value ...................185
On Board Diagnosis Logic ....................................185
DTC Confirmation Procedure ................................186
Wiring Diagram .....................................................187
Diagnostic Procedure ............................................188
Component Inspection ..........................................189
Removal and Installation .......................................191
DTC P0139 HO2S2 ................................................ .192
Component Description ........................................192
CONSULT-II Reference Value in Data Monitor Mode
.192