Nissan Frontier. Manual - part 471

ON BOARD REFUELING VAPOR RECOVERY (ORVR)

EC-455

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d. Apply vacuum pressure to hose end [

−13.3 kPa (−100 mmHg, −3.94 inHg)] with fuel gauge retainer

remaining open and check that the pressure is applicable.

BBIA0568E

EC-456

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POSITIVE CRANKCASE VENTILATION

POSITIVE CRANKCASE VENTILATION

Description

INFOID:0000000009481161

SYSTEM DESCRIPTION

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 venti-

lating 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.

Component Inspection

INFOID:0000000009481162

PCV (POSITIVE CRANKCASE VENTILATION) VALVE

With engine running at idle, remove PCV valve from rocker cover. A

properly working valve makes a hissing noise as air passes through

it. A strong vacuum should be felt immediately when a finger is

placed over valve inlet.

PBIB0492E

PBIB1588E

PBIB1589E

POSITIVE CRANKCASE VENTILATION

EC-457

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PCV VALVE VENTILATION HOSE

1. Check hoses and hose connections for leaks.
2. Disconnect all hoses and clean with compressed air. If any hose

cannot be freed of obstructions, replace.

S-ET277

EC-458

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REFRIGERANT PRESSURE SENSOR

REFRIGERANT PRESSURE SENSOR

Component Description

INFOID:0000000009481163

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.

Diagnosis Procedure

INFOID:0000000009481164

1.

CHECK REFRIGERANT PRESSURE SENSOR OVERALL FUNCTION

1. Start engine and warm it up to normal operating temperature.

2. Turn A/C switch and blower fan switch ON.

3. Check voltage between ECM terminal 39 and ground with CONSULT or tester.

OK or NG

OK

>> INSPECTION END

NG

>> GO TO 2.

2.

CHECK GROUND CONNECTIONS

1. Turn A/C switch and blower fan switch OFF.

2. Stop engine.

3. Loosen and retighten two ground screws on the body. Refer to 

EC-149, "Ground Inspection"

.

OK or NG

OK

>> GO TO 3.

NG

>> Repair or replace ground connections.

3.

CHECK REFRIGERANT PRESSURE SENSOR POWER SUPPLY CIRCUIT

BBIA0627E

PBIB2657E

Voltage: 1.0 - 4.0V

BBIA0614E