Nissan Sentra. Manual - part 332

EC-24

< SYSTEM DESCRIPTION >

[MRA8DE]

COMPONENT PARTS

Engine Oil Temperature Sensor

INFOID:0000000009758339

The engine oil temperature sensor is used to detect the engine oil

temperature. The sensor modifies a voltage signal from the ECM.

The modified signal returns to the ECM as the engine oil tempera-

ture input. The sensor uses a thermistor which is sensitive to the

change in temperature. The electrical resistance of the thermistor

decreases as temperature increases.

<Reference data>

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

EVAP Canister Purge Volume Control Solenoid Valve

INFOID:0000000009758340

The EVAP canister purge volume control solenoid valve uses a ON/

OFF duty to control the flow rate of fuel vapor from the EVAP canis-

ter. The EVAP canister purge volume control solenoid valve is

moved by ON/OFF pulses from the ECM. The longer the ON pulse,

the greater the amount of fuel vapor that will flow through the valve.

EVAP Canister Vent Control Valve

INFOID:0000000009758341

The EVAP canister vent control valve is located on the EVAP canis-

ter and is used to seal the canister vent.

This solenoid valve responds to signals from the ECM. When the

ECM sends an ON signal, the coil in the solenoid valve is energized.

A plunger will then move to seal the canister vent. The ability to seal

the vent is necessary for the on board diagnosis of other evaporative

emission control system components.

This solenoid valve is used only for diagnosis, and usually remains

opened.

When the vent is closed, under normal purge conditions, the evapo-

rative emission control system is depressurized and allows “EVAP

Control System” diagnosis.

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Engine oil 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)

0.9

0.236 - 0.260

110 (230)

0.6

0.143 - 0.153

SEF012P

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COMPONENT PARTS

EC-25

< SYSTEM DESCRIPTION >

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EVAP Control System Pressure Sensor

INFOID:0000000009758342

The EVAP control system pressure sensor detects pressure in the

purge line. The sensor output voltage to the ECM increases as pres-

sure increases.

Exhaust Valve Timing Control Position Sensor

INFOID:0000000009758343

Exhaust valve timing control position sensor detects the protrusion of

the signal plate installed to the exhaust camshaft front end. 

This sensor signal is used for sensing a position of the exhaust cam-

shaft.

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. 

Exhaust Valve Timing Control Solenoid Valve

INFOID:0000000009758344

Exhaust valve timing control solenoid valve is activated by ON/OFF

pulse duty (ratio) signals from the ECM.

The exhaust valve timing control solenoid valve changes the oil

amount and direction of flow through exhaust valve timing control

unit or stops oil flow.

The longer pulse width retards valve angle.

The shorter pulse width advances valve angle.

When ON and OFF pulse widths become equal, the solenoid valve

stops oil pressure flow to fix the exhaust valve angle at the control

position.

Fuel Injector

INFOID:0000000009758345

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.

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EC-26

< SYSTEM DESCRIPTION >

[MRA8DE]

COMPONENT PARTS

Fuel Level Sensor Unit, Fuel Filter and Fuel Pump Assembly

INFOID:0000000009758346

*: ECM determines the start signal status by the signals of engine speed and battery voltage.

The ECM activates the fuel pump for a few seconds after the ignition switch is turned ON to improve engine

start ability. If the ECM receives a engine speed signal from the crankshaft position sensor (POS) and cam-

shaft 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 ignition 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 controls the ON/OFF fuel pump relay, which in turn controls the fuel pump.

Heated Oxygen Sensor 2

INFOID:0000000009758347

DESCRIPTION

The heated oxygen sensor 2, after three way catalyst (manifold),

monitors the oxygen level in the exhaust gas.

Even if switching characteristics of the air fuel ratio (A/F) sensor 1

are shifted, the air fuel ratio is controlled to stoichiometric, by the sig-

nal from the heated oxygen sensor 2.

This sensor is made of ceramic zirconia. The zirconia generates volt-

age from approximately 1 V in richer conditions to 0 V in leaner con-

ditions.

Under normal conditions the heated oxygen sensor 2 is not used for

engine control operation.

HEATED OXYGEN SENSOR 2 HEATER

Heated oxygen sensor 2 heater is integrated in the sensor.

The ECM performs ON/OFF control of the heated oxygen sensor 2 heater corresponding to the engine speed,

amount of intake air and engine coolant temperature. 

Sensor

Input signal to ECM

ECM function

Actuator

Crankshaft position sensor (POS)
Camshaft position sensor (PHASE)

Engine speed*

Fuel pump control

Fuel pump relay
↓
Fuel pump

Battery

Battery voltage*

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.

SEF327R

Engine speed

Heated oxygen sensor 2 heater

Above 3,600 rpm

OFF

Below 3,600 rpm after the following conditions are met.
• Engine: After warming up
• Keeping the engine speed between 3,500 and 4,000 rpm for 1 

minute and at idle for 1 minute under no load

ON

COMPONENT PARTS

EC-27

< SYSTEM DESCRIPTION >

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Ignition Coil with Power Transistor

INFOID:0000000009758348

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.

Intake Valve Timing Control Solenoid Valve

INFOID:0000000009758349

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 Manifold Runner Control Valve

INFOID:0000000009758350

Intake manifold runner control valve  is integrated to intake mani-

fold.

Intake manifold runner control valve is mounted each port of the

intake manifold and opened/closed by the intake manifold runner

control valve motor.

ECM controls the intake manifold runner control valve motor, accord-

ing to signals of engine speed, water temperature, etc. and stabilizes

combustion by generating a strong tunmble flow.

INTAKE MANIFOLD RUNNER CONTROL VALVE MOTOR

Intake manifold runner control valve motor is connected to the rear end of the valve shaft.

The motor opens or closes the valve by the output signal of the ECM.

INTAKE MANIFOLD RUNNER CONTROL VALVE POSITION SENSOR

Intake manifold runner control valve position sensor is connected to the front end of the valve shaft.

The sensor consists of valiable resister. It senses the valve shaft movement and feeds the voltage signals to

the ECM.

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