Geely EC718, EC718RV, EC715, EC715RV. Manual part — 86

1. Operation

The main control device is the crankcase ventilation (PCV)
valve. purged crankcase ventilation valve calculate the
channeling air flow according to manifold vacuum signal. Lower
crankcase ventilation valve parts below the O-ring are exposed
to a vacuum in the intake manifold, parts located between the
lower and upper O-ring are exposed to the crankcase gases.
Purged crankcase ventilation valve allows some internal
vacuum pressure through the valve orifice, and form the low-
pressure condition inside the crankcase. The channeling
crankcase gas is then sucked into intake system and burnt in
the normal combustion process. the channeling gas entering
into the intake manifold must be accurately controlled in order
to maintain idle quality. Must use the correct and proper
calibration of the crankcase ventilation valve. Relationship
between the Channeling air flow and engine manifold vacuum
is shown in the table below:

Manifold

Vacuum

Purged

Crankcase

Ventilation Valve

Opening

Channeling Air

Flow

Low

Large

High

High

Small

Low

2. The Consequences Of Abnormal Operation

Valve or hose blockage may lead to the following conditions:

–

Poor engine idling.

–

Engine stalls or engine idle speed is too low.

–

Engine crankcase pressure is too high.

–

Engine oil leaks.

–

Engine oil enters into the air filter.

–

Engine has sludge.

–

Engine oil consumption is high.

–

Excessive exhaust emissions.

Engine

Auxiliary Emission Control JL4G18-D

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2.4.3 System Working Principle
2.4.3.1 Heated Type Oxygen Sensor Working
Principle

–

Oxygen sensor's sensing element is a porous ceramic tube,
the outer wall surrounded by the engine exhaust and inside
exposed to atmosphere. Sensing ceramic wall is a solid
electrolyte containing an electric heating tube. When the
sensor ceramic tube temperature reaches 350°C (662 ºF ),
it will have a solid electrolyte properties.

–

Oxygen sensor's senses ceramic oxygen ion concentration
inside and outside difference and sends it out as a voltage
signal.

–

The output voltage level is due to internal electronic
ceramic tubes movement.

–

Meet EOBD vehicles self inspect whether the sensor
information is accurate.

–

Heated resistor resistance at room temperature is 2.5-4.9
Ω.

Note

–

During the oxygen sensor repair procedure, it is
prohibited to use cleaning agent, oily liquids or
volatile solids.

–

After the replacement of oxygen sensor, apply a layer
of anti-rust oil to oxygen sensor threads to prevent
rust. Oxygen sensors have electrical cables. The
other end of electrical cable is a connector. The
external packaging is anti-fire sleeve. A new oxygen
sensor will be coated with anti-rust oil on the threads,
during installation do not remove these anti-rust oil.

2.4.3.2 Canister Solenoid Valve Working
Principle

1. Canister solenoid valve consists of the electromagnetic

coil, armature and valves so on. Inlet port has a filter.

2. On one hand, air flow through the Canister solenoid valve

is related to ECM output to the Canister solenoid valve
electrical pulse duty cycle; on the other hand, it is related
to the pressure difference between the Canister solenoid
valve inlet port and outlet port. When there is no electrical
pulses, the Canister solenoid valve will be turned off.

3. ECM provides signals to control the Canister solenoid valve

power according to various engine sensor signals, and
indirectly controls the flow of the clean air.

4. When the engine coolant temperature, engine running time

and engine load etc. meet the preset requirements, ECM
will instruct Canister solenoid valve to start working. In the
following situations canister solenoid valve will not work:

•

Engine cold start.

•

Engine coolant temperature is relatively low.

•

Engine idle.

•

Engine load is high.

•

Important sensor system faults.

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Auxiliary Emission Control JL4G18-D

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2.4.4 Component Locator
2.4.4.1 Canister Location

2

1

FE11-2025b

Legend

1. Canister Assembly

2. Canister Ventilation Filter

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Auxiliary Emission Control JL4G18-D

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2.4.4.2 Canister Solenoid Valve Location

FE02-2026b

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Auxiliary Emission Control JL4G18-D

Engine