Nissan Pathfinder. Manual — part 434

EC-42

< SYSTEM DESCRIPTION >

[VQ35DE]

SYSTEM

THROTTLE CONTROL : System Description

INFOID:0000000009178044

SYSTEM DIAGRAM

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

SYSTEM DESCRIPTION

ECM calculates the value of signal transmitted from the accelerator pedal and activates the throttle valve by

transmitting a control signal to the electric throttle control actuator. This allows the optimum throttle angle and

improves drivability and fuel consumption. In addition, ECM learns the fully closed position every time when

the ignition switch is turned OFF to improve the accuracy in throttle valve position.

When a malfunction occurs in the throttle control system, the throttle valve is closed by the return spring and

maintains the minimum engine speed by holding a slightly opened condition which is close to the fully opened

condition. This allows the securing of brake system, power steering system, and electric system and the

ensuring of the safety.

INTAKE VALVE TIMING CONTROL
INTAKE VALVE TIMING CONTROL : System Description

INFOID:0000000009178045

SYSTEM DIAGRAM

JSBIA3066GB

JMBIA1830GB

SYSTEM

EC-43

< SYSTEM DESCRIPTION >

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SYSTEM DESCRIPTION

This mechanism hydraulically controls cam phases continuously with the fixed operating angle of the intake

valve.

The ECM receives signals such as crankshaft position, camshaft position, engine speed, and engine coolant

temperature. Then, the ECM sends ON/OFF pulse duty signals to the intake valve timing (IVT) control sole-

noid valve depending on driving status. This makes it possible to control the shut/open timing of the intake

valve to increase engine torque in low/mid speed range and output in high-speed range.

ENGINE PROTECTION CONTROL AT LOW ENGINE OIL PRESSURE
ENGINE PROTECTION CONTROL AT LOW ENGINE OIL PRESSURE : System De-
scription

INFOID:0000000009178046

SYSTEM DIAGRAM

SYSTEM DESCRIPTION

• The engine protection control at low engine oil pressure warns the driver of a decrease in engine oil pres-

sure by the oil pressure warning lamp before the engine becomes damaged.

• When detecting a decrease in engine oil pressure at an engine speed less than 1,000 rpm, ECM transmits

an oil pressure warning lamp signal to the combination meter. The combination meter turns ON the oil pres-

sure warning lamp, according to the signal.

• When detecting a decrease in engine oil pressure at an engine speed 1,000 rpm or more, ECM transmits an

oil pressure warning lamp signal to the combination meter.

The combination meter turns ON the oil pressure warning lamp, according to the signals. When detecting a

decrease in engine oil pressure, ECM cuts fuel if the engine speed exceeds the specified value.

*: When detecting a normal engine oil pressure, ECM turns OFF the oil pressure warning lamp.

JMBIA0060GB

JSBIA1588GB

Decrease in engine oil pressure

Engine speed

Combination meter

Fuel cut

Oil pressure warning lamp

Detection

Less than 1,000 rpm

ON*

NO

1,000 rpm or more

ON

YES

EC-44

< SYSTEM DESCRIPTION >

[VQ35DE]

SYSTEM

FUEL FILLER CAP WARNING SYSTEM
FUEL FILLER CAP WARNING SYSTEM : System Description

INFOID:0000000009178047

SYSTEM DIAGRAM

SYSTEM DESCRIPTION

The fuel filler cap warning system alerts the driver to the prevention of the fuel filler being left uncapped and

malfunction occurrences after refueling, by turning ON the fuel filler cap warning display on the combination

meter.

ECM judges a refueled state, based on a fuel level signal transmitted from the combination meter.

When a very small leak is detected through the EVAP leak diagnosis performed after judging the refueled

state, ECM transmits a fuel filler cap warning display signal (request for display ON) to the combination meter

via CAN communication.

When receiving the signal, the combination meter turns ON the fuel filler cap warning display.

CAUTION:

Check fuel filler cap installation condition when the fuel filler cap warning display turns ON.

Reset Operation

The fuel filler cap warning lamp tunes OFF, according to any condition listed below:

• Reset operation is performed by operating the meter control switch on the combination meter.

- When the reset operation is performed, the combination meter transmits a fuel filler cap warning reset signal

to ECM via CAN communication. ECM transmits a fuel filler cap warning display signal (request for display

OFF) to the combination meter via CAN communication. When receiving the signal, the combination meter

turns OFF the fuel filler cap warning display.

• EVAP leak diagnosis result is normal.

• Fuel refilled.

• DTC erased by using CONSULT.

NOTE:

MIL turns ON if a malfunction is detected in leak diagnosis results again at the trip after the fuel filler cap warn-

ing display turns ON/OFF.

VARIABLE INDUCTION AIR SYSTEM

JSBIA1456GB

SYSTEM

EC-45

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VARIABLE INDUCTION AIR SYSTEM : System Description

INFOID:0000000009178048

SYSTEM DIAGRAM

SYSTEM DESCRIPTION

In the medium speed range, the ECM sends the ON signal to the VIAS control solenoid valve. This signal

introduces the intake manifold vacuum into the power valve actuator and therefore closes the power valve.

Under this condition, the pressure waves of the exhaust stroke do not disturb the pressure waves of the intake

stroke of each opposite bank. Therefore, charging efficiency is increased together with the effect of the long

intake passage.

However, in the high speed range, the ECM sends the OFF signal to the VIAS control solenoid valve and the

power valve is opened. Under this condition, the pressure waves of intake stroke are resonant with those of

each opposite bank exhaust stroke. Therefore, charging efficiency is also increased.

In addition, both valves 1 and 2 are opened or closed in other ranges mentioned above. Thus maximum

charging efficiency is obtained for the various driving conditions.

VACUUM HOSE DRAWING

JMBIA1831GB

JMBIA0181GB