Nissan X-Trail 32. Manual - part 829

COMPONENT PARTS

EC-445

< SYSTEM DESCRIPTION >

[QR25DE]

C

D

E

F

G

H

I

J

K

L

M

A

EC

N

P

O

THROTTLE CONTROL MOTOR RELAY

Power supply for the throttle control motor is provided to the ECM via throttle control motor relay. The throttle
control motor relay is ON/OFF controlled by the ECM. When the ignition switch is turned ON, the ECM sends
an ON signal to throttle control motor relay and battery voltage is provided to the ECM. When the ignition
switch is turned OFF, the ECM sends an OFF signal to throttle control motor relay and battery voltage is not
provided to the ECM.

THROTTLE CONTROL MOTOR

The throttle control motor is operated by the ECM and it opens and closes the throttle valve.
The current opening angle of the throttle valve is detected by the throttle position sensor and it provides feed-
back to the ECM to control the throttle control motor to make the throttle valve opening angle properly in
response to driving condition.

THROTTLE POSITION SENSOR

The throttle position sensor responds to the throttle valve movement.
The throttle position sensor has two sensors. These sensors are a
kind of potentiometers which transform the throttle valve position into
output voltage, and emit the voltage signal to the ECM. In addition,
these sensors detect the opening and closing speed of the throttle
valve and feed the voltage signals to the ECM. The ECM judges the
current opening angle of the throttle valve from these signals and the
ECM controls the throttle control motor to make the throttle valve
opening angle properly in response to driving condition.

Ignition Coil With Power Transistor

INFOID:0000000010986204

The ignition signal from the ECM is sent to and amplified by the
power transistor. The power transistor turns ON and OFF the ignition
coil primary circuit. This ON/OFF operation induces the proper high
voltage in the coil secondary circuit.

Fuel Injector

INFOID:0000000010986205

The fuel injector is a small, precise solenoid valve. When the ECM
supplies a ground to the fuel injector circuit, the coil in the fuel injec-
tor is energized. The energized coil pulls the ball valve back and
allows fuel to flow through the fuel injector into the intake manifold.
The amount of fuel injected depends upon the injection pulse dura-
tion. Pulse duration is the length of time the fuel injector remains
open. The ECM controls the injection pulse duration based on
engine fuel needs.

Fuel Level Sensor Unit and Fuel Pump

INFOID:0000000010986206

FUEL PUMP

PBIB0145E

JPBIA4613ZZ

JPBIA5845ZZ

EC-446

< SYSTEM DESCRIPTION >

[QR25DE]

COMPONENT PARTS

The ECM activates the fuel pump for 1 second after the ignition
switch is turned ON to improve engine start ability. If the ECM
receives a engine speed signal from the camshaft position sensor
(PHASE), it knows that the engine is rotating, and causes the pump
to operate. If the engine speed signal is not received when the igni-
tion switch is ON, the engine stalls. The ECM stops pump operation
and prevents battery discharging, thereby improving safety. The
ECM does not directly drive the fuel pump. It sends the control signal
to the fuel pump control module, which in turn controls the fuel
pump.

FUEL LEVEL SENSOR

The fuel level sensor is mounted in the fuel level sensor unit.
The sensor detects a fuel level in the fuel tank and transmits a signal to the combination meter. The combina-
tion meter sends the fuel level sensor signal to the ECM via the CAN communication line.
It consists of two parts, one is mechanical float and the other is variable resistor. Fuel level sensor output volt-
age changes depending on the movement of the fuel mechanical float.

Mass Air Flow Sensor (With Intake Air Temperature Sensor)

INFOID:0000000010986207

MASS AIR FLOW SENSOR

The mass air flow sensor

 is placed in the stream of intake air. It

measures the intake flow rate by measuring a part of the entire
intake flow. The MAF sensor controls the temperature of the heater
in sensing element to a certain amount. The temperature distribution
around the heater changes according to the increase in intake air
volume. The change is detected by a thermistor and the air volume
data is sent to ECM by the MAF sensor.

INTAKE AIR TEMPERATURE SENSOR

The intake air temperature sensor is built-into mass air flow sensor. The sensor detects intake air temperature
and transmits a signal to the ECM.
The temperature sensing unit uses a thermistor which is sensitive to the change in temperature.

<Reference data>

*: These data are reference values on the diagnosis tool.

JSBIA4496ZZ

Condition

Fuel pump operation

Ignition switch is turned to ON.

Operates for 1 second.

Engine running and cranking

Operates.

When engine is stopped

Stops in 1.5 seconds.

Except as shown above

Stops.

PBIA9559J

Intake air temperature

[

°

C (

°

F)]

Voltage

*

 (V)

25 (77)

1.9 – 2.1

80 (176)

3.2 – 3.4

COMPONENT PARTS

EC-447

< SYSTEM DESCRIPTION >

[QR25DE]

C

D

E

F

G

H

I

J

K

L

M

A

EC

N

P

O

Engine Coolant Temperature Sensor

INFOID:0000000010986208

The engine coolant temperature sensor is used to detect the engine
coolant temperature. The sensor modifies a voltage signal from the
ECM. The modified signal returns to the ECM as the engine coolant
temperature input. The sensor uses a thermistor which is sensitive to
the change in temperature. The electrical resistance of the ther-
mistor decreases as temperature increases.

<Reference data>

*: These data are reference values and are measured between ECM terminals.

Crankshaft Position Sensor (POS)

INFOID:0000000010986209

The crankshaft position sensor (POS) is located on the oil pan facing
the gear teeth (cogs) of the signal plate. It detects the fluctuation of
the engine revolution.
The sensor consists of a permanent magnet and Hall IC.
When the 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.
The ECM receives the voltage signal and detects the fluctuation of
the engine revolution.
ECM receives the signals as shown in the figure.

JPBIA5280ZZ

Engine coolant temperature

[

°

C (

°

F)]

Voltage

*

 (V)

Resistance (k

Ω

)

–10 (14)

4.4

7.0 - 11.4

20 (68)

3.5

2.37 - 2.63

50 (122)

2.2

0.68 - 1.00

90 (194)

1.0

0.236 - 0.260

SEF012P

JPBIA5848ZZ

JMBIA0714GB

EC-448

< SYSTEM DESCRIPTION >

[QR25DE]

COMPONENT PARTS

Camshaft Position Sensor (PHASE)

INFOID:0000000010986210

The camshaft position sensor (PHASE) senses the retraction of
intake camshaft to identify a particular cylinder. The camshaft posi-
tion 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. 
ECM receives the signals as shown in the figure.

Intake Valve Timing Control Solenoid Valve

INFOID:0000000010986211

Intake valve timing control solenoid valve is activated by ON/OFF
pulse duty (ratio) signals from the ECM.
The intake valve timing control solenoid valve changes the oil
amount and direction of flow through intake valve timing control unit
or stops oil flow.
The longer pulse width advances valve angle.
The shorter pulse width retards valve angle.
When ON and OFF pulse widths become equal, the solenoid valve
stops oil pressure flow to fix the intake valve angle at the control
position.

Intake Valve Timing Intermediate Lock Control Solenoid Valve

INFOID:0000000010986212

Intake valve timing intermediate lock control solenoid valve is acti-
vated by ON/OFF signals from the ECM.
The intake valve timing intermediate lock control solenoid valve
opens/closes the path of oil pressure acting on the lock key in the
camshaft sprocket (INT).
• When the solenoid valve becomes ON, oil pressure to the lock key

is trained to perform intermediate lock.

• When the solenoid valve becomes OFF, oil pressure is acted on

the lock key to release the intermediate lock.

JPBIA5846ZZ

JMBIA0714GB

PBIB1842E

PBIB1842E