DIESEL EXHAUST FLUID
Diesel Exhaust Fluid (DEF) sometimes known simply by the name of its active
component, UREA – is a key component of selective catalytic reduction (SCR)
systems, which help diesel vehicles meet stringent emission regulations. DEF is a
liquid reducing agent that reacts with engine exhaust in the presence of a catalyst to
convert smog-forming nitrogen oxides (NOx) into harmless nitrogen and water vapor.
Your vehicle is equipped with a Selective Catalytic Reduction system in order to meet
the very stringent diesel emissions standards required by the Environmental Protec-
tion Agency. Selective Catalytic Reduction (SCR) is the first and only technology in
decades to be as good for the environment as it is good for business and vehicle
performance.
The purpose of the SCR system is to reduce levels of NOx (oxides of nitrogen emitted
from engines) that are harmful to our health and the environment to an almost
near-zero level. Small quantities of Diesel Exhaust Fluid (DEF) are injected into the
exhaust upstream of a catalyst where, when vaporized, convert smog-forming
nitrogen oxides (NOx) into harmless nitrogen (N2) and water vapor (H2O), two
natural components of the air we breathe. You can operate with the comfort that your
vehicle is contributing to a cleaner, healthier world environment for this and
generations to come.
System Overview
This vehicle is equipped with a Diesel Exhaust Fluid (DEF) injection system and a
Selective Catalytic Reduction (SCR) catalyst to meet the emission requirements.
The DEF injection system consists of the following components:
• DEF tank
• DEF pump
• DEF injector
• Electronically-heated DEF lines
• NOx sensors
• Temperature sensors
• SCR catalyst
The DEF injection system and SCR catalyst enable the achievement of diesel
emissions requirements; while maintaining outstanding fuel economy, drivability,
torque and power ratings.
NOTE:
• Your vehicle is equipped with a DEF injection system. You may occasionally hear
an audible clicking noise. This is normal operation.
• The DEF pump will run for a period of time after engine shutdown to purge the DEF
system. This is normal operation.
D I E S E L
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