fuel NISSAN X-TRAIL 2003 Electronic Service Manual

EC-18
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PRECAUTIONS
lAfter performing each TROUBLE DIAGNOSIS, perform
“DTC Confirmation Procedure” or “Overall Function
Check”.
The DTC should not be displayed in the “DTC Confirmation
Procedure” if the repair is completed. The “Overall Func-
tion Check” should be a good result if the repair is com-
pleted.
lWhen measuring ECM signals with a circuit tester, never
allow the two tester probes to contact.
Accidental contact of probes will cause a short circuit and
damage the ECM power transistor.
lDo not use ECM ground terminals when measuring input/
output voltage. Doing so may result in damage to the ECM's
transistor. Use a ground other than ECM terminals, such as
the ground.
lDo not operate fuel pump when there is no fuel in lines.
lTighten fuel hose clamps to the specified torque.
SAT652J
SEF348N
PBIB0513E

EC-20
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PREPARATION
PREPARATION
PFP:00002
Special Service ToolsEBS00B0M
The actual shapes of Kent-Moore tools may differ from those of special service tools illustrated here.
Commercial Service ToolsEBS00B0N
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 (Kent-
Moore No.)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-24
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ENGINE CONTROL SYSTEM
System Chart
EBS00B0Q
*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) SystemEBS00B0R
INPUT/OUTPUT SIGNAL CHART
*1: Under normal conditions, this sensor is not for engine control operation.
*2: This signal is sent to the ECM through CAN communication line.Input (Sensor) ECM Function Output (Actuator)
lCamshaft position sensor (PHASE)
lCrankshaft position sensor (POS)
lMass air flow sensor
lEngine coolant temperature sensor
lHeated oxygen sensor 1
lThrottle position sensor
lAccelerator pedal position sensor
lPark/neutral position (PNP) switch
lIntake air temperature sensor
lPower steering pressure sensor
lIgnition switch
lBattery voltage
lKnock sensor
lRefrigerant pressure sensor
lHeated oxygen sensor 2 *1
lTCM (Transmission control module) *2
lESP/TCS/ABS control unit *2
lWheel sensor
lAir conditioner switch
lElectrical 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
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 *1 Density of oxygen in exhaust gas
ESP/TCS/ABS control unit *2 ESP/TCS operation command
Wheel sensor Vehicle speed
Air conditioner switch Air conditioner operation

ENGINE CONTROL SYSTEM
EC-25
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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
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.

lDuring warm-up
lWhen starting the engine
lDuring acceleration
lHot-engine operation
lWhen selector lever is changed from “N” to “D”
lHigh-load, high-speed operation

lDuring deceleration
lDuring 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 toEC-160
. 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.
lDeceleration and acceleration
lHigh-load, high-speed operation
lMalfunction of heated oxygen sensor 1 or its circuit
lInsufficient activation of heated oxygen sensor 1 at low engine coolant temperature
lHigh engine coolant temperature
lDuring warm-up
lAfter shifting from “N” to “D”
lWhen starting the engine
PBIB0121E

EC-26
[QR (WITH EURO-OBD)]
ENGINE CONTROL SYSTEM
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-
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.
SEF337W

ENGINE CONTROL SYSTEM
EC-27
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Electronic Ignition (EI) SystemEBS00B0S
INPUT/OUTPUT SIGNAL CHART
SYSTEM DESCRIPTION
The ignition timing is controlled by the ECM to maintain the best air-
fuel ratio for every running condition of the engine. The ignition tim-
ing data is stored in the ECM. This data forms the map shown.
The ECM receives information such as the injection pulse width and
camshaft position sensor signal. Computing this information, ignition
signals are transmitted to the power transistor.
e.g.,N:1,800rpm,Tp:1.50msec
A°BTDC
During the following conditions, the ignition timing is revised by the
ECM according to the other data stored in the ECM.
lAt starting
lDuring warm-up
lAt idle
lAt low battery voltage
lDuring acceleration
The knock sensor retard system is designed only for emergencies. The basic ignition timing is programmed
within the anti-knocking zone, if recommended fuel is used under dry conditions. The retard system does not
operate under normal driving conditions. If engine knocking occurs, the knock sensor monitors the condition.
The signal is transmitted to the ECM. The ECM retards the ignition timing to eliminate the knocking condition.
Air Conditioning Cut ControlEBS00B0T
INPUT/OUTPUT SIGNAL CHART
SYSTEM DESCRIPTION
This system improves engine operation when the air conditioner is used.
Under the following conditions, the air conditioner is turned off.
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
SEF742M
Sensor Input Signal to ECM ECM function Actuator
Air conditioner switch Air conditioner “ON” signal
Air conditioner
cut controlAir conditioner relay Throttle position sensor Throttle valve opening angle
Crankshaft position sensor (POS) Engine speed
Engine coolant temperature sensor Engine coolant temperature
Ignition switch Start signal
Refrigerant pressure sensor Refrigerant pressure
Power steering pressure sensor Power steering operation
Wheel sensor Vehicle speed

EC-28
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ENGINE CONTROL SYSTEM
lWhen the accelerator pedal is fully depressed.
lWhen cranking the engine.
lAt high engine speeds.
lWhen the engine coolant temperature becomes excessively high.
lWhen operating power steering during low engine speed or low vehicle speed.
lWhen engine speed is excessively low.
lWhen refrigerant pressure is excessively low or high.
Fuel Cut Control (at No Load and High Engine Speed)EBS00B0U
INPUT/OUTPUT SIGNAL CHART
SYSTEM DESCRIPTION
If the engine speed is above 1,800 rpm with no load (for example, in neutral and engine speed over 1,800
rpm) fuel will be cut off after some time. The exact time when the fuel is cut off varies based on engine speed.
Fuel cut will operate until the engine speed reaches 1,500 rpm, then fuel cut is cancelled.
NOTE:
This function is different from deceleration control listed under “Multiport Fuel Injection (MFI) System”,EC-24
.
CAN communicationEBS00B0V
SYSTEM DESCRIPTION
CAN (Controller Area Network) is a serial communication line for real time application. It is an on-vehicle mul-
tiplex communication line with high data communication speed and excellent error detection ability. Many elec-
tronic control units are equipped onto a vehicle, and each control unit shares information and links with other
control units during operation (not independent). In CAN communication, control units are connected with 2
communication lines (CAN H line, CAN L line) allowing a high rate of information transmission with less wiring.
Each control unit transmits/receives data but selectively reads required data only.
FOR A/T MODELS
System Diagram
Input/Output Signal Chart
T: Transmit R: Receive Sensor Input Signal to ECMECM func-
tionActuator
Park/neutral position (PNP) switch Neutral position
Fuel cut
controlFuel injectors Throttle position sensor Throttle position
Accelerator pedal position sensor Accelerator pedal position
Engine coolant temperature sensor Engine coolant temperature
Crankshaft position sensor (POS) Engine speed
Wheel sensor Vehicle speed
SKIA0884E
Signals ECM TCM
Engine speed signal T R
Engine coolant temperature signal T R

EC-34
[QR (WITH EURO-OBD)]
BASIC SERVICE PROCEDURE
DIAGNOSTIC PROCEDURE
If idle air volume learning cannot be performed successfully, proceed as follows:
1.Check that throttle valve is fully closed.
2.Check PCV valve operation.
3.Check that downstream of throttle valve is free from air leakage.
4.When the above three items check out OK, engine component parts and their installation condi-
tion are questionable. Check and eliminate the cause of the problem.
It is useful to performEC-103, "
TROUBLE DIAGNOSIS - SPECIFICATION VALUE".
5.If any of the following conditions occur after the engine has started, eliminate the cause of the
problem and perform “Idle air volume learning” all over again:
–Engine stalls.
–Erroneous idle.
Fuel Pressure CheckEBS00B0Z
FUEL PRESSURE RELEASE
Before disconnecting fuel line, release fuel pressure from fuel line to eliminate danger.
NOTE:
Prepare pans or saucers under the disconnected fuel line because the fuel may spill out. The fuel pres-
sure cannot be completely released because QR engine models do not have fuel return system.
With CONSULT-II
1. Turn ignition switch “ON”.
2. Perform “FUEL PRESSURE RELEASE” in “WORK SUPPORT”
mode with CONSULT-II.
3. Start engine.
4. After engine stalls, crank it two or three times to release all fuel
pressure.
5. Turn ignition switch “OFF”.
Without CONSULT-II
1. Remove fuel pump fuse located in fuse box.
2. Start engine.
3. After engine stalls, crank it two or three times to release all fuel
pressure.
4. Turn ignition switch “OFF”.
5. Reinstall fuel pump fuse after servicing fuel system.
FUEL PRESSURE CHECK
CAUTION:
lThe fuel hose connection method used when taking fuel pressure check must not be used for
other purposes.
lTake care for not to scratch and not to put debris around connection area when servicing, so that
the quick connector keeps sealability with O-rings inside.
1. Release fuel pressure to zero. Refer toEC-34, "
FUEL PRESSURE RELEASE".
2. Prepare fuel hose for fuel pressure check, and connect fuel pressure gauge.
lUse suitable fuel hose for fuel pressure check (genuine NISSAN fuel hose without quick connector).
SEF214Y
PBIB0508E

BASIC SERVICE PROCEDURE
EC-35
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lTo avoid unnecessary force or tension to hose, use moderately long fuel hose for fuel pressure check.
lDo not use the fuel hose for checking fuel pressure with damage or cracks on it.
lUse Pressure Gauge to check fuel pressure.
3. Remove fuel hose. Refer toEM-17, "
INTAKE MANIFOLD".
lDo not twist or kink fuel hose because it is plastic hose.
lDo not remove fuel hose from quick connector.
lKeep the original fuel hose to be free from intrusion of dust or foreign substances with a suitable cover.
4. Install the fuel pressure gauge as shown in the figure.
lWipe off oil or dirt from hose insertion part using cloth moist-
ened with gasoline.
lApply proper amount of gasoline between top of the fuel tube
and No.1 spool.
lInsert fuel hose for fuel pressure check until it touches the
No.1 spool on fuel tube.
lUse NISSAN genuine hose clamp (part number: 16439
N4710 or 16439 40U00).
lWhen reconnecting fuel line, always use new clamps.
lWhen reconnecting fuel hose, check the original fuel hose for
damage and abnormality.
lUse a torque driver to tighten clamps.
lInstall hose clamp to the position within 1 - 2 mm (0.04 - 0.08
in).
lMake sure that clamp screw does not contact adjacent parts.
5. After connecting fuel hose for fuel pressure check, pull the hose
with a force of approximately 98 N (10 kg, 22 lb) to confirm fuel
tube does not come off.
6. Turn ignition switch "ON", and check for fuel leakage.
7. Start engine and check for fuel leakage.
8. Read the indication of fuel pressure gauge.
lDo not perform fuel pressure check with system operating. Fuel pressure gauge may indicate false
readings.
lDuring fuel pressure check, confirm for fuel leakage from fuel connection every 3 minutes.
9. If result is unsatisfactory, go to next step.
10. Check the following.
lFuel hoses and fuel tubes for clogging
lFuel filter for clogging
lFuel pump
lFuel pressure regulator for clogging
If OK, replace fuel pressure regulator.
If NG, repair or replace.Tightening torque: 1 - 1.5 N·m (0.1 - 0.15 kg-m,
9-13in-lb)
At idling:
Approximately 350 kPa (3.5 bar, 3.7 kg/cm
2,51psi)
PBIB0669E
PBIB0670E

ON BOARD DIAGNOSTIC (OBD) SYSTEM
EC-37
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Emission-related Diagnostic InformationEBS00BM7
EMISSION-RELATED DIAGNOSTIC INFORMATION ITEMS
´: Applicable —: Not applicable
DTC*1
Items
(CONSULT-II screen terms)SRT codeTest value/
Te s t l i m i t
(GST only)1st trip
DTC*1Reference page
CONSULT-II
GST*2ECM*3
U1000 1000*6 CAN COMM CIRCUIT*7 — —EC-114
P0000 0000NO DTC IS DETECTED.
FURTHER TESTING
MAY BE REQUIRED.————
P0011 0011 INT/V TIM CONT-B1 — —´EC-117
P0031 0031 HO2S1 HTR (B1)´´´*4EC-120
P0032 0032 HO2S1 HTR (B1)´´´*4EC-120
P0037 0037 HO2S2 HTR (B1)´´´*4EC-125
P0038 0038 HO2S2 HTR (B1)´´´*4EC-125
P0102 0102 MAF SEN/CIRCUIT*5 — —´EC-130
P0103 0103 MAF SEN/CIRCUIT*5 — —´EC-130
P0112 0112 IAT SEN/CIRCUIT — —´EC-136
P0113 0113 IAT SEN/CIRCUIT — —´EC-136
P0117 0117 ECT SEN/CIRCUIT*5 — —´EC-141
P0118 0118 ECT SEN/CIRCUIT*5 — —´EC-141
P0120 0120 THRTL POS SEN/CIRC*5 — —´EC-146
P0121 0121 APP SEN/CIRCUIT — —´EC-154
P0132 0132 HO2S1 (B1)´´´*4EC-160
P0133 0133 HO2S1 (B1)´´´*4EC-166
P0134 0134 HO2S1 (B1)´´´*4EC-174
P0138 0138 HO2S2 (B1)´´´*4EC-181
P0139 0139 HO2S2 (B1)´´´*4EC-187
P0171 0171 FUEL SYS-LEAN-B1 — —´EC-194
P0172 0172 FUEL SYS-RICH-B1 — —´EC-200
P0300 0300 MULTI CYL MISFIRE — —´EC-206
P0301 0301 CYL 1 MISFIRE — —´EC-206
P0302 0302 CYL 2 MISFIRE — —´EC-206
P0303 0303 CYL 3 MISFIRE — —´EC-206
P0304 0304 CYL 4 MISFIRE — —´EC-206
P0327 0327 KNOCK SEN/CIRC-B1 — —´EC-212
P0328 0328 KNOCK SEN/CIRC-B1 — —´EC-212
P0335 0335 CKP SEN/CIRCUIT — —´EC-217
P0340 0340 CMP SEN/CIRCUIT — —´EC-223
P0420 0420 TW CATALYST SYS-B1´´´*4EC-229
P0444 0444 PURG VOLUME CONT/V — —´EC-233
P0445 0445 PURG VOLUME CONT/V — —´EC-233
P0500 0500 VEH SPEED SEN/CIRC*9 — —´EC-239
P0550 0550 PW ST P SEN/CIRC — —´EC-244
P0605 0605 ECM — —´EC-249
P0650 0650 MIL/CIRC — —´EC-252