List Of Important Abbreviations (Glossary) - Bosch Denoxtronic-Set 2 Handbuch

12. List of important abbreviations (glossary)

AdBlue / DEF
A common term for AdBlue is also DEF (DEF is the same as AdBlue)
AdBlue (DIN 70070/AUS32) is the trade name for a clear, synthetically manufactured 32.5 %
solution of super pure urea in demineralized water which is used for the treatment of exhaust
gases in an SCR catalytic converter.
The vehicle is fitted with an additional tank for the AdBlue. The AdBlue consumption rate is
approx. 4-6 % of the diesel fuel consumption. At low temperatures AdBlue is heated to prevent
it from freezing or to preheat it. This is necessary as its high water content means that AdBlue
freezes at approx. –11 °C.
Ammonia
Ammonia may escape if too much AdBlue is metered into the catalytic converter.
Ammonia is a chemical compound of nitrogen and hydrogen. Its empirical formula is NH
Ammonia is an extremely pungent, colourless, toxic gas which causes irritation on damp areas
of the skin and has an asphyxiating effect if inhaled in large quantities. Even low concentrations
cause serious irritation of the respiratory system and eyes.
Ammonia dissolved in water is known as ammonium hydroxide. The solution exhibits an
alkaline reaction. Mixtures of ammonia and air are explosive in the 15.5 to 30% by volume
ammonia range. Decomposition into nitrogen and hydrogen may occur on hot surfaces as of
630 °C; metals act as catalysts for this decomposition reaction, with the result that the
conversion of nitrogen oxide may already take place at surface temperatures as of 180 °C in
modern SCR vehicle catalytic converters.
CAN
Abbreviation for "Controller Area Network" (standardized motor vehicle data bus developed by
BOSCH). A CAN permits the interlinkage of the many electronic control units in motor vehicles
and thus the efficient exchange of information and data.
All stations are connected to the CAN bus with equal priority. A header in the data transmission
protocol (CAN protocol) enables each recipient to determine whether or not a message is of
relevance. This also specifies the hierarchy of the messages. Test bits show the recipient
whether or not a message is complete.
CCA or CCV
The cooling/return quantity in the AdBlue circuit is influenced by a control valve/restrictor
located in the return of the AdBlue circuit. One of the three following versions may be fitted
depending on the series status and vehicle manufacturer:
- In the first years of production, the delivery module was always fitted with an electrically
actuated cooling circuit control valve (CCV, Cooling Control Valve).
- In a later version, the cooling circuit control valve was replaced by a fixed restrictor in the
metering module. The return pipe is still looped through the delivery module (CCA, Cooling
Circuit Adapter).
- In the most recent version the return is routed directly to the tank from the metering module
with fixed restrictor.
Note: Older versions may still be fitted in new vehicles. The version fitted in the vehicle
concerned is shown by the Identification in the diagnostic tester.
DEF (Diesel Exhaust Fluid)
Is the same as AdBlue (A common term for AdBlue is also DEF)
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