Emission Control System; Crankcase Emission Control System; Evaporative Emission Control System Including Onboard Refueling Vapor Recovery (Orvr) - Hyundai Sonata Hybrid 2021 Owner's Manual

EMISSION CONTROL SYSTEM

The emission control system of your
vehicle is covered by a written limited
warranty. Please see the warranty
information contained in the Owner's
Handbook & Warranty Information
booklet in your vehicle.
Your vehicle is equipped with an
emission control system to meet all
applicable emission regulations. There
are three emission control systems, as
follows.

(1) Crankcase emission control system

(2) Evaporative emission control system
(3) Exhaust emission control system
In order to ensure the proper function
of the emission control systems, it
is recommended that you have your
vehicle inspected and maintained
by an authorized HYUNDAI dealer in
accordance with the maintenance
schedule in this manual.
NOTICE
For the Inspection and Maintenance
Test (with Electronic Stability Control
(ESC) system)
• To prevent the vehicle from misfiring
during dynamometer testing, turn
the Electronic Stability Control
(ESC) system off by pressing the ESC
switch (ESC OFF light illuminated).
• After dynamometer testing is
completed, turn the ESC system back
on by pressing the ESC switch again.
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 crankcase. This system supplies
fresh 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
into the induction system.
2. Evaporative Emission Control
System Including Onboard
Refueling Vapor Recovery
(ORVR)
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 surge tank
through the purge control solenoid 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.
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