Nissan March K13. Manual - part 140

COMPONENT PARTS

EC-21

< SYSTEM DESCRIPTION >

[HR12DE (TYPE 1)]

Ignition Coil With Power Transistor

INFOID:0000000005991042

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.

Accelerator Pedal Position Sensor

INFOID:0000000005991043

The accelerator pedal position sensor is installed on the accelerator
pedal assembly. The sensor detects the accelerator position and
sends a signal to the ECM.
Accelerator pedal position sensor has two sensors. These sensors
are a kind of potentiometer which transform the accelerator pedal
position into output voltage, and emit the voltage signals to the ECM.
The ECM judges the current opening angle of the accelerator pedal
from these signals and controls the throttle control motor based on
these signals.
Idle position of the accelerator pedal is determined by the ECM
receiving the signal from the accelerator pedal position sensor. The
ECM uses this signal for engine operations such as fuel cut.

Mass Air Flow Sensor

INFOID:0000000005991044

MASS AIR FLOW SENSOR

The mass air flow sensor (1) is placed in the stream of intake air. It
measures the intake flow rate by measuring a part of the entire
intake flow. The mass air flow sensor controls the temperature of the
hot wire to a certain amount. The heat generated by the hot wire is
reduced as the intake air flows around it. The greater air flow, the
greater the heat loss.
Therefore, the electric current supplied to hot wire is changed to
maintain the temperature of the hot wire as air flow increases. The
ECM detects the air flow by means of this current change.

INTAKE AIR TEMPERATURE SENSOR

The intake air temperature sensor is built-into the mass air flow sensor. The sensor detects intake air temper-
ature and transmits a signal to the ECM.
The temperature sensing unit uses a thermistor which is sensitive to the change in temperature. Electrical
resistance of the thermistor decreases in response to the rise in temperature.
<Reference data>

*: These data are reference values and are measured between ECM terminals 46
(Intake air temperature sensor) and 55 (Sensor ground).

PBID0206J

PBIB1741E

PBIA9559J

Intake air temperature

[

C (

F)]

Voltage*

(V)

Resistance

Ω

)

25 (77)

3.3

1.800 - 2.200

80 (176)

1.2

0.283 - 0.359

SEF012P

EC-22

< SYSTEM DESCRIPTION >

[HR12DE (TYPE 1)]

COMPONENT PARTS

Electric Throttle Control Actuator

INFOID:0000000005991045

OUTLINE

Electric throttle control actuator consists of throttle body, throttle valve, throttle control motor and throttle posi-
tion sensor.

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. The throttle position
sensor provides feedback to the ECM, when opens/closes the throttle valve in response to driving conditions
via the throttle control motor.
ECM inhibits THROTTLE VALVE CLOSED POSITION LEARNING under clogging-prone conditions to reduce
the clogging in the throttle valve closed position. When detecting a clogging in the throttle valve closed posi-
tion, ECM maximizes the motor driving torque of the electronic throttle to eliminate the clogging.

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 potentiometer which transform the throttle valve position into
output voltage, and emit the voltage signal to the ECM. The ECM
judges the current opening angle of the throttle valve from these sig-
nals and controls the throttle valve opening angle in response to
driving conditions via the throttle control motor.

Crankshaft Position Sensor (POS)

INFOID:0000000005991046

The crankshaft position sensor (POS) is located on the transmission
housing 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.

JSBIA0270GB

PBIB0145E

PBIA9209J

COMPONENT PARTS

EC-23

< SYSTEM DESCRIPTION >

[HR12DE (TYPE 1)]

ECM receives the signals as shown in the figure.

Camshaft Position Sensor (PHASE)

INFOID:0000000005991047

The camshaft position sensor (PHASE) senses the protrution of the
signal plate installed to the camshaft (INT) rear end to identify a par-
ticular 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.
ECM receives the signals as shown in the figure.

Engine Coolant Temperature Sensor

INFOID:0000000005991048

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.

JSBIA0394GB

PBIA9209J

JSBIA0394GB

SEF594K

EC-24

< SYSTEM DESCRIPTION >

[HR12DE (TYPE 1)]

COMPONENT PARTS

<Reference data>

*: These data are reference values and are measured between ECM terminals 38
(Engine coolant temperature sensor) and 44 (Sensor ground).

Fuel Injector

INFOID:0000000005991049

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 Pump

INFOID:0000000005991050

The ECM activates the fuel pump for 1 second after the ignition
switch is turned ON to improve engine startability. 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.

Engine coolant temperature

[

C (

F)]

Voltage* (V)

Resistance (k

Ω

)

−

10 (14)

4.4

7.0 - 11.4

20 (68)

3.5

2.35 - 2.73

50 (122)

2.2

0.68 - 1.00

90 (194)

0.9

0.236 - 0.260

SEF012P

PBIA9664J

JSBIA0498ZZ

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.

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