2005 NISSAN X-TRAIL Starting

EC-36
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ENGINE CONTROL SYSTEM

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 whether 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-179, "
DTC P0132 HO2S1" . 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 (A/T models)

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-
inally designed. Both manufacturing differences (i.e., mass air flow sensor hot wire) 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.
PBIB0121E

ENGINE CONTROL SYSTEM
EC-37
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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) SystemEBS010LA
INPUT/OUTPUT SIGNAL CHART
*1: This signal is sent to the ECM through CAN communication line.
*2: ECM determines the start signal status by the signals of engine speed and battery voltage.
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: 1,800 rpm, Tp: 1.50 msec
A °BTDC
During the following conditions, the ignition timing is revised by the
ECM according to the other data stored in the ECM.

At starting

During warm-up
SEF337W
Sensor Input Signal to ECMECM func-
tionActuator
Crankshaft position sensor (POS)
Engine speed*
2
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
Knock sensor Engine knocking
Park/neutral position (PNP) switch Gear position
Battery
Battery voltage*
2
Wheel sensor*1Vehicle speed
SEF742M

ON BOARD DIAGNOSTIC (OBD) SYSTEM
EC-67
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codes can be identified by using the CONSULT-II or GST. A DTC will be used as an example for how to read a
code.
A particular trouble code can be identified by the number of four-digit numeral flashes. The “zero” is indicated
by the number of ten flashes. The length of time the 1,000th-digit numeral flashes on and off is 1.2 seconds
consisting of an ON (0.6-second) - OFF (0.6-second) cycle.
The 100th-digit numeral and lower digit numerals consist of a 0.3-second ON and 0.3-second OFF cycle.
A change from one digit numeral to another occurs at an interval of 1.0-second OFF. In other words, the later
numeral appears on the display 1.3 seconds after the former numeral has disappeared.
A change from one trouble code to another occurs at an interval of 1.8-second OFF.
In this way, all the detected malfunctions are classified by their DTC numbers. The DTC 0000 refers to no mal-
function. (See EC-19, "
INDEX FOR DTC" )
How to Erase Diagnostic Test Mode II (Self-diagnostic Results)
The DTC can be erased from the back up memory in the ECM by depressing accelerator pedal. Refer to EC-
66, "HOW TO SWITCH DIAGNOSTIC TEST MODE" .

If the battery is disconnected, the DTC will be lost from the backup memory within 24 hours.

Be careful not to erase the stored memory before starting trouble diagnoses.
DIAGNOSTIC TEST MODE II — HEATED OXYGEN SENSOR 1 MONITOR
In this mode, the MI displays the condition of the fuel mixture (lean or rich) which is monitored by the heated
oxygen sensor 1.
*: Maintains conditions just before switching to open loop.
To check the heated oxygen sensor 1 function, start engine in the Diagnostic Test Mode II and warm it up until
engine coolant temperature indicator points to the middle of the gauge.
Next run engine at about 2,000 rpm for about 2 minutes under no-load conditions. Then make sure that the MI
comes ON more than 5 times within 10 seconds with engine running at 2,000 rpm under no-load.
OBD System Operation ChartEBS010LO
RELATIONSHIP BETWEEN MI, 1ST TRIP DTC, DTC, AND DETECTABLE ITEMS

When a malfunction is detected for the first time, the 1st trip DTC and the 1st trip freeze frame data are
stored in the ECM memory.

When the same malfunction is detected in two consecutive trips, the DTC and the freeze frame data are
stored in the ECM memory, and the MI will come on. For details, refer to EC-52, "
Tw o Tr i p D e t e c t i o n
Logic" .
PBIA3905E
MI Fuel mixture condition in the exhaust gas Air fuel ratio feedback control condition
ON Lean
Closed loop system
OFF Rich
*Remains ON or OFF Any condition Open loop system

EC-98
[QR (WITH EURO-OBD)]
TROUBLE DIAGNOSIS

19 PEVAP canister purge vol-
ume control solenoid valve[Engine is running]

Idle speedBATTERY VOLTAGE
(11 - 14V)
[Engine is running]

Engine speed is about 2,000 rpm (More than
100 seconds after starting engine)Approximately 10V
22
23
41
42G/B
R/B
L/B
Y/BInjector No. 3
Injector No. 1
Injector No. 4
Injector No. 2[Engine is running]

Warm-up condition

Idle speed
NOTE:
The pulse cycle changes depending on rpm
at idleBATTERY VOLTAGE
(11 - 14V)
[Engine is running]

Warm-up condition

Engine speed is 2,000 rpmBATTERY VOLTAGE
(11 - 14V)
24 G/WHeated oxygen sensor 1
heater[Engine is running]

Warm-up condition

Engine speed is below 3,600 rpmApproximately 7.0V
[Engine is running]

Engine speed is above 3,600 rpmBATTERY VOLTAGE
(11 - 14V)
29 BSensor ground
(Camshaft position sen-
sor)[Engine is running]

Warm-up condition

Idle speedApproximately 0V
30 BSensor ground
(Crankshaft position sen-
sor)[Engine is running]

Warm-up condition

Idle speedApproximately 0V
34 Y/GIntake air temperature
sensor[Engine is running]Approximately 0 - 4.8V
Output voltage varies with intake
air temperature. TERMI-
NAL
NO.WIRE
COLORITEM CONDITION DATA (DC Voltage)
PBIB0050E
PBIB0520E
PBIB0529E
PBIB0530E
PBIB0519E

EC-108
[QR (WITH EURO-OBD)]
TROUBLE DIAGNOSIS

INT/A TEMP SE [°C]
or [°F]××
The intake air temperature (determined by the
signal voltage of the intake air temperature
sensor) is indicated.
START SIGNAL
[ON/OFF]××

Indicates start signal status [ON/OFF] com-
puted by the ECM according to the signals of
engine speed and battery voltage.
After starting the engine, [OFF] is
displayed regardless of the
starter signal.
CLSD THL POS
[ON/OFF]××

Indicates idle position [ON/OFF] computed by
the ECM according to the accelerator pedal
position sensor signal.
AIR COND SIG
[ON/OFF]××

Indicates [ON/OFF] condition of the air condi-
tioner switch as determined by the air condi-
tioner signal.
P/N POSI SW
[ON/OFF]××

Indicates [ON/OFF] condition from the park/
neutral position (PNP) switch signal.
PW/ST SIGNAL
[ON/OFF]××

[ON/OFF] condition of the power steering
pressure sensor as determined by the power
steering pressure sensor is indicated.
LOAD SIGNAL [ON/
OFF]××

Indicates [ON/OFF] condition from the electri-
cal load signal.
ON: Rear window defogger switch is ON and/
or lighting switch is in 2nd position (placed in
LOW position for models with Xenon head-
lamp).
OFF: Both rear window defogger switch and
lighting switch are OFF.
IGNITION SW
[ON/OFF]×

Indicates [ON/OFF] condition from ignition
switch.
HEATER FAN SW
[ON/OFF]×

Indicates [ON/OFF] condition from the heater
fan switch signal.
BRAKE SW
[ON/OFF]×

Indicates [ON/OFF] condition from the stop
lamp switch signal.
INJ PULSE-B1
[msec]×

Indicates the actual fuel injection pulse width
compensated by ECM according to the input
signals.
When the engine is stopped, a
certain computed value is indi-
cated.
IGN TIMING [BTDC]×

Indicates the ignition timing computed by ECM
according to the input signals.
When the engine is stopped, a
certain value is indicated.
CAL/LD VALUE [%]

“Calculated load value” indicates the value of
the current airflow divided by peak airflow.
MASS AIRFLOW
[g·m/s]

Indicates the mass airflow computed by ECM
according to the signal voltage of the mass air
flow sensor.
PURG VOL C/V [%]

Indicates the EVAP canister purge volume
control solenoid valve control value computed
by the ECM according to the input signals.

The opening becomes larger as the value
increases.
INT/V TIM (B1)
[°CA]

Indicates [°CA] of intake camshaft advanced
angle.
INT/V SOL (B1) [%]

The control value of the intake valve timing
control solenoid valve (determined by ECM
according to the input signal) is indicated.

The advance angle becomes larger as the
value increases Monitored item
[Unit]ECM
INPUT
SIGNALSMAIN
SIG-
NALSDescription Remarks

DTC P0340 CMP SENSOR (PHASE)
EC-257
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DTC P0340 CMP SENSOR (PHASE)PFP:23731
Component DescriptionEBS010Q1
The camshaft position sensor (PHASE) senses the retraction of
intake valve camshaft to identify a particular cylinder. The camshaft
position sensor (PHASE) senses the piston position.
When the crankshaft position sensor (POS) system becomes inoper-
ative, the camshaft position sensor (PHASE) provides various con-
trols of engine parts instead, utilizing timing of cylinder identification
signals.
The sensor consists of a permanent magnet and Hall IC.
When engine is running, the high and low parts of the teeth cause
the gap with the sensor to change.
The changing gap causes the magnetic field near the sensor to
change.
Due to the changing magnetic field, the voltage from the sensor changes.
On Board Diagnosis LogicEBS010Q2
DTC Confirmation ProcedureEBS010Q3
NOTE:
If DTC Confirmation Procedure has been previously conducted, always turn ignition switch OFF and wait at
least 10 seconds before conducting the next test.
TESTING CONDITION:
Before performing the following procedure, confirm that battery voltage is more than 10.5V with igni-
tion switch ON.
WITH CONSULT-II
1. Turn ignition switch ON.
2. Select “DATA MONITOR” mode with CONSULT-II.
3. Crank engine for at least 2 seconds and run it for at least 5 sec-
onds at idle speed.
4. If 1st trip DTC is detected, go to EC-259, "
Diagnostic Procedure"
.
If 1st trip DTC is not detected, go to next step.
5. Maintain engine speed at more than 800 rpm for at least 5 sec-
onds.
6. If 1st trip DTC is detected, go to EC-259, "
Diagnostic Procedure"
.
WITH GST
Follow the procedure “WITH CONSULT-II” above.
PBIB0562E
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0340
0340Camshaft position sensor
(PHASE) circuit

The cylinder No. signal is not sent to ECM
for the first few seconds during engine
cranking.

The cylinder No. signal is not set to ECM
during engine running.

The cylinder No. signal is not in the normal
pattern during engine running.

Harness or connectors
(The sensor circuit is open or shorted.)

Camshaft position sensor (PHASE)

Camshaft (Intake)

Starter motor (Refer to SC-23, "START-
ING SYSTEM" .)

Starting system circuit (Refer to SC-23,
"STARTING SYSTEM" .)

Dead (Weak) battery
SEF058Y

DTC P0340 CMP SENSOR (PHASE)
EC-259
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Specification data are reference values and are measured between each terminal and ground.
Pulse signal is measured by CONSULT-II.
CAUTION:
Do not use ECM ground terminals when measuring input/output voltage. Doing so may result in dam-
age to the ECM's transistor. Use a ground other than ECM terminals, such as the ground.
: Average voltage for pulse signal (Actual pulse signal can be confirmed by oscilloscope.)
Diagnostic ProcedureEBS010Q5
1. CHECK STARTING SYSTEM
Turn ignition switch to START position.
Ye s o r N o
Ye s > > G O T O 2 .
No >> Check starting system. (Refer to SC-23, "
STARTING SYSTEM" .)
TERMI-
NAL
NO.WIRE
COLORITEM CONDITION DATA (DC Voltage)
13 L/WCamshaft position sensor
(PHASE)[Engine is running]

Warm-up condition

Idle speed
NOTE:
The pulse cycle changes depending on rpm
at idle1.0 - 4.0V
[Engine is running]

Engine speed is 2,000 rpm1.0 - 4.0V
29 BSensor ground
(Camshaft position sen-
sor)[Engine is running]

Warm-up condition

Idle speedApproximately 0V
PBIB0525E
PBIB0526E
Does the engine turn over?
Does the starter motor operate?

EC-272
[QR (WITH EURO-OBD)]
DTC P0444 EVAP CANISTER PURGE VOLUME CONTROL SOLENOID VALVE

Specification data are reference values and are measured between each terminal and ground.
Pulse signal is measured by CONSULT-II.
CAUTION:
Do not use ECM ground terminals when measuring input/output voltage. Doing so may result in dam-
age to the ECM's transistor. Use a ground other than ECM terminals, such as the ground.
: Average voltage for pulse signal (Actual pulse signal can be confirmed by oscilloscope.) TERMI-
NAL
NO.WIRE
COLORITEM CONDITION DATA (DC Voltage)
19 PEVAP canister purge vol-
ume control solenoid valve[Engine is running]

Idle speedBATTERY VOLTAGE
(11 - 14V)
[Engine is running]

Engine speed is about 2,000 rpm (More than
100 seconds after starting engine)Approximately 10V
PBIB0050E
PBIB0520E