1

2

FE02-0081b

1.

Release  fuel  system  pressure.  Refer  to 

2.3.8.1

 

Fuel

Pressure Release Procedure

.

2.

Disconnect  the  battery  negative  cable.  Refer  to

2.11.8.1

 

Battery Disconnection

.

3.

Remove  the  rear  seat  cushion.  Refer  to 

12.7.3.4

 

Rear

Seat Cushion Replacement

.

4.

Remove fuel pump assembly. Refer to 

2.3.8.3

 

Fuel Pump

Assembly Replacement

.

5.

Disconnect the fuel level sensor wires (1) and (2).

FE02-0082b

6.

Disconnect the fuel level sensor wiring harness cable tie.

7.

Hold the fuel level sensor buckle upward and remove the
fuel level sensor.

Installation Procedure:

FE02-0083b

1.

Install the fuel level sensor to the fuel pump assembly.

Engine

Fuel System JL4G18-D

2-255

FE02-0084b

2.

Connect the black wires to the fuel level sensor.

FE02-0085b

3.

Connect the black wires to the fuel level sensor.

4.

Fix the fuel gage wiring harness with a cable tie.

5.

Install the fuel pump.

6.

Install the rear seat cushion.

7.

Connect the battery negative cable.

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2.4 Auxiliary Emission Control JL4G18-
D

2.4.1 Specifications
2.4.1.1 Fastener Tightening Specifications

Applications

Model

Specifications

Metric (Nm)

US English (lb-ft)

Canister Ventilation Filter
Mounting Bracket Retaining
Bolt

M6 × 1.25 × 20

7-9

5.2-6.7

Canister Solenoid Valve
Bracket Retaining Bolts

M6 × 1.25 × 20

7-9

5.2-6.7

Canister Assembly Retaining
Bolts

M6 × 1.25 × 20

8-10

6.0-7.4

Engine

Auxiliary Emission Control JL4G18-D

2-257

2.4.2 Description and Operation
2.4.2.1 Heated Oxygen Sensor (HO

2

S)

Heated Oxygen Sensors (HO

2

S) are installed before and after

the three-way catalytic converter. Heated oxygen sensor sends
signals to the engine control module (ECM) indicating oxygen
content in the exhaust. the engine control module controls the
fuel injectors to change the engine Air-Fuel ratio. The ideal Air-
Fuel ratio is 14.7:1, at this time the catalytic converters is most
efficient. As the fuel injection system continuously measures
and adjusts Air-Fuel ratio, it is called "closed loop" control.

1. Open-loop

When the engine has just started and the speed is higher than
400 rpm, the system enter "open loop" operation. In the open-
loop mode, the engine control module (ECM) ignores the signal
from the heated oxygen (HO

2

S) signal and according to signals

from the engine coolant temperature sensor (ECT) and intake
pressure  temperature  sensor  to  calculate  the  Air-Fuel  ratio.
Sensors will remain in the "open loop" mode, until the following
conditions are met:

–

Heated  oxygen  sensor  voltage  output  changes,  showing
that the temperature is high enough and the system can
enter the normal operation.

–

Engine  coolant  temperature  sensor  in  higher  than  the
specified temperature.

–

The  engine  has  been  started  for  the  specified  period  of
time.

2. Closed-loop

In the above mentioned situation, the specific values depend
on  different  engines  and  are  stored  in  electrically  erasable
programmable  read-only  memory  (EEPROM).  When  these
conditions  are  met,  the  system  enters  into  "closed  loop"
operation.  In  the  "closed  loop",  the  engine  control  module
calculates Air-Fuel ratio according to oxygen sensor signals (ie,
fuel  injector  connected  timing),  so  that  the  Air-Fuel  ratio  is
always very close to 14.7:1.

Note

Once the engine control module confirms oxygen sensor
faulty,  the  system  will  be  immediately  in  "open  loop"
control,  that  is  the  Air-Fuel  ratio  is  no  longer  adjusted
according to the oxygen sensor signals.

2.4.2.2 Evaporative Emission Control System

Evaporative emission control system uses the basic principle
of Canister storage method. This method transfers fuel vapor
from fuel tank to the carbon storage devices in order to save
the steam when the vehicle is not running. When the engine is
running,  the  fuel  vapor  is  sucked  out  from  the  Canister  and
burnt in the normal combustion process. Gasoline vapor from
the fuel tank flows into the fuel vapor recovery pipe. The vapor
is absorbed by the Canister. After the engine runs the required
time, the engine control module provides a ground circuit, so
that evaporative Canister clean-up solenoid valve is turned on
and the air is drawn into the Canister and mixed with vapor.
The  mixture  is  then  sucked  into  the  intake  manifold.  The
evaporative canister clean-up is controlled by the pulse-width
modulated  solenoid  valve  (PWM)  signal  to  open  or  close.
According to the operating conditions determined by air flow,
fuel  adjustment  and  intake  air  temperature,  evaporative
Canister PWM duty cycle changes.

The  following  conditions  can  cause  poor  idling,  stalling  and
poor performance:

–

Canister Solenoid Valve Inoperative

–

Canister Damage

–

Hose  Disconnected,  Cracking,  Improperly  Connected  To
The Pipeline

Evaporative canister is an emission control device containing
active carbon particles. Evaporative Canister is used to store
fuel vapor from fuel tank. When certain conditions are met, the
engine control module will provide the Canister solenoid valve
power, so that the fuel will be sucked into the engine cylinder
and burnt off.

2.4.2.3  Purged  Crankcase  Ventilation  (PCV)
System

Compressed  combustion  gases  fleeing  into  the  crankcase
through  the  piston  rings  is  known  as  channeling  gas.
Channeling  gas  contains  nitrogen  oxides,  carbon  monoxide
and hydrocarbons. Crankcase ventilation system prevents the
channeling  gas  entering  into  the  atmosphere.  Crankcase
ventilation  system  will  force  the  channeling  gas  crankshaft
back  into  the  intake  system  and  the  combustion  chamber.
Crankcase  ventilation  system  consists  of  the  following
components:

–

Purged Crankcase Ventilation Valve

–

Crankcase Ventilation Tube

–

Hose and Connectors

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Engine