Emission Control Systems - Hyundai 2001 Sonata Owner's Manual

7. EMISSION CON-
TROL SYSTEMS
H010A01L-AAT
EMISSION CONTROL SYSTEM
Your Hyundai is equipped with an emission
control system to meet all requirements of the
U.S. Environmental Protection Agency or Cali-
fornia Air Resources Board.
There are three emission control systems which
are as follows.
(1) Crankcase emission control system
(2) Evaporative emission control system
(3) Exhaust emission control system
In order to assure the proper function of the
emission control systems, it is recommended
that you have your car inspected and main-
tained by an authorized Hyundai dealer in ac-
cordance with the maintenance schedule in this
manual.
Caution for Inspection and Maintenance Test
(2.5 V6 Vehicle with Traction Control Sys-
tem)
o To prevent the vehicle from misfiring
during dynamometer testing, disconnect
the ABS connector located on the left
side of the engine compartment.
o For more information, see shop manual
(BRa-11, Wheel Speed Sensor)

EMISSION CONTROL SYSTEMS

H010B01A-AAT
1. Crankcase Emission Control
System
The positive crankcase ventilation system is
employed to prevent air pollution caused by
blow-by gases being emitted from the crank-
case. This system supplies filtered air to the
crankcase through the air intake hose. Inside
the crankcase, the fresh air mixes with blow-by
gases, which then pass through the PCV valve
and into the induction system.
H010C01S-AAT
2. Evaporative Emission Control (In-
cluding ORVR: Onboard Refueling
Vapor Recovery) System
The Evaporative Emission Control System is
designed to prevent fuel vapors from escaping
into the atmosphere.
(The ORVR system is designed to allow the
vapors from the fuel tank to be loaded into
a canister while refueling at the gas station,
preventing the escape of fuel vapors into
the atmosphere.)
Canister
Fuel vapors generated inside the fuel tank are
absorbed and stored in the onboard canister.
When the engine is running, the fuel vapors
absorbed in the canister are drawn into the
induction system through the purge control so-
lenoid valve.
Purge Control Solenoid Valve (PCSV)
The purge control solenoid valve is controlled
by the Engine Control Module (ECM); when the
engine coolant temperature is low during idling,
the PCSV closes so that evaporated fuel is not
taken into the engine. After the engine warms-
up during ordinary driving, the PCSV opens to
introduce evaporated fuel to the engine.
H010D01A-AAT
3. Exhaust Emission Control System
The Exhaust Emission Control System is a
highly effective system which controls exhaust
emissions while maintaining good vehicle per-
formance.
H010E01Y-AAT
EGR System (If installed)
This system helps reduce nitrogen oxides by
recirculating a part of the exhaust gas into the
engine, thereby reducing cylinder combustion
temperature, which results in lower output of
oxides of nitrogen.
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