Nissan Sentra. Manual - part 333

EC-28

< SYSTEM DESCRIPTION >

[MRA8DE]

COMPONENT PARTS

Intake Manifold Tuning Valve

INFOID:0000000009758351

Intake manifold tuning (IMT) valve   is integrated to intake manifold.

Intake manifold tuning valve consists of valve and motor.

Intake manifold tuning valve is used to control the suction passage of

the intake manifold tuning system.

INTAKE MANIFOLD TUNING VALVE MOTOR

Intake manifold tuning valve motor is connected to the front end of the valve shaft.

The motor is operated by the ECM and it opens and closes the intake manifold tuning valve.

Knock Sensor

INFOID:0000000009758352

The knock sensor is attached to the cylinder block. It senses engine

knocking using a piezoelectric element. A knocking vibration from

the cylinder block is sensed as vibrational pressure. This pressure is

converted into a voltage signal and sent to the ECM.

Mass Air Flow Sensor (with Intake Air Temperature Sensor)

INFOID:0000000009758353

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 mass air flow 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 sen-

sor.

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.

JSBIA3183ZZ

JSBIA0284ZZ

PBIA9559J

Intake air temperature

[

°C (°F)]

Voltage

*

 (V)

25 (77)

1.9 – 2.1

80 (176)

3.2 – 3.4

COMPONENT PARTS

EC-29

< SYSTEM DESCRIPTION >

[MRA8DE]

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Park/Neutral Position Switch

INFOID:0000000009758354

Park/Neutral Position Switch is installed to manual transaxle. The switch detects the neutral position and

transmits a voltage signal.

Refrigerant Pressure Sensor

INFOID:0000000009758355

The refrigerant pressure sensor is installed at the condenser of the air conditioner system. The sensor uses an

electrostatic volume pressure transducer to convert refrigerant pressure to voltage. The voltage signal is sent

to ECM, and ECM controls cooling fan system.

Stop Lamp Switch & Brake Pedal Position Switch

INFOID:0000000009758356

Stop lamp switch and brake pedal position switch are installed to

brake pedal bracket.

ECM detects the state of the brake pedal by those two types of input

(ON/OFF signal).

Transmission Range Switch

INFOID:0000000009758357

Transmittion Range Switch is installed to automatic transmission and CVT transaxle. The switch detects the

state of the gear position (N range and P range) and transmits a voltage signal to ECM.

PBIB2657E

JSBIA0308ZZ

Brake pedal

Brake pedal position switch

Stop lamp switch

Released

ON

OFF

Depressed

OFF

ON

EC-30

< SYSTEM DESCRIPTION >

[MRA8DE]

STRUCTURE AND OPERATION

STRUCTURE AND OPERATION

Positive Crankcase Ventilation

INFOID:0000000009758358

This system returns blow-by gas to the intake manifold.

The positive crankcase ventilation (PCV) valve is provided to conduct crankcase blow-by gas to the intake

manifold.

During partial throttle operation of the engine, the intake manifold sucks the blow-by gas through the PCV

valve.

Normally, the capacity of the valve is sufficient to handle any blow-by and a small amount of ventilating air.

The ventilating air is then drawn from the air inlet tubes into the crankcase. In this process the air passes

through the hose connecting air inlet tubes to rocker cover.

Under full-throttle condition, the manifold vacuum is insufficient to draw the blow-by flow through the valve.

The flow goes through the hose connection in the reverse direction.

On vehicles with an excessively high blow-by, the valve does not

meet the requirement. This is because some of the flow will go

through the hose connection to the air inlet tubes under all condi-

tions.

PBIB0492E

PBIB1588E

STRUCTURE AND OPERATION

EC-31

< SYSTEM DESCRIPTION >

[MRA8DE]

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On Board Refueling Vapor Recovery (ORVR)

INFOID:0000000009758359

From the beginning of refueling, the air and vapor inside the fuel tank go through refueling EVAP vapor cut

valve and EVAP/ORVR line to the EVAP canister. The vapor is absorbed by the EVAP canister and the air is

released to the atmosphere.

When the refueling has reached the full level of the fuel tank, the refueling EVAP vapor cut valve is closed and

refueling is stopped because of auto shut-off. The vapor which was absorbed by the EVAP canister is purged

during driving.

WARNING:

When conducting inspections below, be sure to observe the following:

• Put a “CAUTION: FLAMMABLE” sign in workshop.

• Do not smoke while servicing fuel system. Keep open flames and sparks away from work area.

• Be sure to furnish the workshop with a CO

2

 fire extinguisher.

CAUTION:

• Before removing fuel line parts, carry out the following procedures:

- Put drained fuel in an explosion-proof container and put lid on securely.

- Release fuel pressure from fuel line. Refer to 

EC-481, "Inspection"

.

- Disconnect battery ground cable.

• Always replace O-ring when the fuel gauge retainer is removed.

• Do not kink or twist hose and tube when they are installed.

• Do not tighten hose and clamps excessively to avoid damaging hoses.

• After installation, run engine and check for fuel leaks at connection.

• Do not attempt to top off the fuel tank after the fuel pump nozzle shuts off automatically.

Continued refueling may cause fuel overflow, resulting in fuel spray and possibly a fire.

JMBIA1930GB