2001 NISSAN X-TRAIL OBD port

DTC U1000 CAN COMMUNICATION LINE
EC-515
[QR25(WITHOUT EURO-OBD)]
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Diagnostic ProcedureEBS00ODV
1.INSPECTION START
1. Turn ignition switch “ON”.
2. Select “CAN DIAG SUPPORT MNTR” in “DATA MONITOR” mode with CONSULT-II.
3. Print out the CONSULT-II screen.
A/T models
>> Go to LAN-5, "
CAN SYSTEM (FOR A/T MODELS)" or LAN-12, "CAN SYSTEM (FOR M/T MOD-
ELS)" .
PBIB0538E

EC-714
[QR25(WITHOUT EURO-OBD)]
VIAS
VIAS
PFP:14956
DescriptionEBS00NKK
SYSTEM DESCRIPTION
When the engine is running at low or medium speed, the power valve is fully closed. Under this condition, the
effective suction port length is equivalent to the total length of the intake manifold collector's suction port
including the intake valve. This long suction port provides increased air intake which results in improved suc-
tion efficiency and higher torque generation.
The surge tank and one-way valve are provided. When engine is running at high speed, the ECM sends the
signal to the VIAS control solenoid valve. This signal introduces the intake manifold vacuum into the power
valve actuator and therefore opens the power valve to two suction passages together in the collector.
Under this condition, the effective port length is equivalent to the length of the suction port provided indepen-
dently for each cylinder. This shortened port length results in enhanced engine output with reduced suction
resistance under high speeds.
COMPONENT DESCRIPTION
Power Valve
The power valve is installed in intake manifold collector and used to
control the suction passage of the variable induction air control sys-
tem. It is set in the fully closed or fully opened position by the power
valve actuator operated by the vacuum stored in the surge tank. The
vacuum in the surge tank is controlled by the VIAS control solenoid
valve.
Sensor Input Signal to ECM ECM function Actuator
Mass air flow sensor Amount of intake air
VIAS control VIAS control solenoid valve Throttle position sensor Throttle position
Accelerator pedal position sensor Accelerator pedal position
Ignition switch Start signal
Crankshaft position sensor (POS)
Camshaft position sensor (PHASE)Engine speed
Engine coolant temperature sensor Engine coolant temperature
PBIB0843E
PBIB0946E

EC-720
[QR25(WITHOUT EURO-OBD)]
VIAS
9. CHECK VIAS CONTROL SOLENOID VALVE
Refer to EC-720, "
Component Inspection" .
OK or NG
OK >> GO TO 10.
NG >> Replace VIAS control solenoid valve.
10. CHECK INTERMITTENT INCIDENT
Refer to EC-506, "
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT" .
>>INSPECTION END
Component InspectionEBS00NKP
VIAS CONTROL SOLENOID VALVE
With CONSULT-II
1. Reconnect harness connectors disconnected.
2. Turn ignition switch ON.
3. Perform “VIAS SOL VALVE” in “ACTIVE TEST” mode.
4. Check air passage continuity and operation delay time under the
following conditions.
Operation takes less than 1 second.
Without CONSULT-II
Check air passage continuity and operation delay time under the fol-
lowing conditions.
Operation takes less than 1 second.
VACUUM TANK
1. Disconnect vacuum hose connected to vacuum tank.
2. Connect a vacuum pump to the port A of vacuum pump.
3. Apply vacuum and make sure that vacuum exists at the port B .
Condition
VIAS SOL VALVEAir passage continuity
between A and BAir passage continuity
between A and C
ON Yes No
OFF No Yes
PBIB0177E
ConditionAir passage continuity
between A and BAir passage continuity
between A and C
12V direct current supply
between terminals 1 and 2Ye s N o
No supply No Yes
MEC488B
PBIB0846E

EC-746
[QR25(WITHOUT EURO-OBD)]
EVAPORATIVE EMISSION SYSTEM
EVAPORATIVE EMISSION SYSTEM
PFP:14950
DescriptionEBS00NLC
SYSTEM DESCRIPTION
The evaporative emission system is used to reduce hydrocarbons emitted into the atmosphere from the fuel
system. This reduction of hydrocarbons is accomplished by activated charcoals in the EVAP canister.
The fuel vapor in the sealed fuel tank is led into the EVAP canister which contains activated carbon and the
vapor is stored there when the engine is not operating or when refueling to the fuel tank.
The vapor in the EVAP canister is purged by the air through the purge line to the intake manifold when the
engine is operating. EVAP canister purge volume control solenoid valve is controlled by ECM. When the
engine operates, the flow rate of vapor controlled by EVAP canister purge volume control solenoid valve is
proportionally regulated as the air flow increases.
EVAP canister purge volume control solenoid valve also shuts off the vapor purge line during decelerating and
idling.
PBIB0491E

EC-748
[QR25(WITHOUT EURO-OBD)]
EVAPORATIVE EMISSION SYSTEM
Component Inspection
EBS00NLD
EVAP CANISTER
Check EVAP canister as follows:
1. Block port B . Orally blow air through port A .
Check that air flows freely through port C .
2. Block port A . Orally blow air through port B .
Check that air flows freely through port C .
FUEL CHECK VALVE
1. Blow air through connector on fuel tank side.
A considerable resistance should be felt and a portion of air flow
should be directed toward the EVAP canister side.
2. Blow air through connector on EVAP canister side.
Air flow should be smoothly directed toward fuel tank side.
3. If fuel check valve is suspected of not properly functioning in
steps 1 and 2 above, replace it.
FUEL TANK VACUUM RELIEF VALVE (BUILT INTO FUEL FILLER CAP)
1. Wipe clean valve housing.
2. Check valve opening pressure and vacuum.
3. If out of specification, replace fuel filler cap as an assembly.
EVAP CANISTER PURGE VOLUME CONTROL SOLENOID VALVE
Refer to EC-248, "Component Inspection" .
PBIB0663E
SEF552Y
SEF989X
Pres-
sure:15.3 - 20.0 kPa (0.153 - 0.200 bar,
0.156 - 0.204 kg/cm
2 , 2.22 - 2.90 psi)
Va c u u m :−6.0 to −3.3 kPa (−0.060 to −0.033 bar,
−0.061 to −0.034 kg/cm
2 , −0.87 to −0.48 psi)
SEF943S

ENGINE CONTROL SYSTEM
EC-765
[QR20(WITH EURO-OBD)]
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EC
System ChartEBS00MSA
*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) SystemEBS00MSB
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)
●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
●ESP/TCS/ABS control unit *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
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-767
[QR20(WITH EURO-OBD)]
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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-769
[QR20(WITH EURO-OBD)]
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EC
●When the accelerator pedal is fully depressed.
●When cranking the engine.
●At high engine speeds.
●When the engine coolant temperature becomes excessively high.
●When operating power steering during low engine speed or low vehicle speed.
●When engine speed is excessively low.
●When refrigerant pressure is excessively low or high.
Fuel Cut Control (at No Load and High Engine Speed)EBS00MSE
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-765
.
CAN CommunicationEBS00NBG
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 coolant temperature signal T R
Accelerator pedal position signal T R
A/T self-diagnosis signal R T