DEF System Parts
John Deere DEF (Diesel Exhaust Fluid) system parts are essential for meeting environmental standards by reducing harmful nitrogen oxide (NOx) emissions in diesel engines. The DEF system employs a specialized fluid that is injected into the exhaust stream, converting toxic NOx into harmless nitrogen and water vapor.
Operate Efficiently with A Proper DEF System
A properly functioning DEF system from Koenig Equipment allows equipment to operate efficiently. Supporting cleaner machine operation, improved fuel efficiency, and reduced downtime by alerting operators to issues.
Keeping Your DEF System Healthy
The diesel exhaust fluid (DEF) system includes the tank, pump or supply module, dosing unit, lines, heaters and sensors. When any of them has a problem, the machine will warn you and may reduce power until it is fixed.
Most DEF problems start with the fluid. Use only fresh DEF, keep containers sealed and clean, and store it out of direct sun. Never put anything else in the DEF tank, and do not add anything to keep it from freezing because the system is built to thaw it.
DEF parts are specific to your machine and engine, so have your model and serial number ready, along with any warning code the display shows.
Order online through John Deere's parts store with Koenig as your dealer, then pick it up at your Koenig store or have it shipped. If you are not sure you have the right part, call or stop by our parts counter with your model and serial number and we will look it up for you.
DEF System Parts FAQ
My machine shows a DEF warning. What should I do?
Check the DEF level and quality first. If the warning stays on, write down the code on the display and call our service department. Do not ignore it, because the machine may reduce power.
Can DEF go bad?
Yes. Heat and contamination break it down over time, so buy what you will use and keep it sealed and out of the sun.
How do I find the right part number?
Look up your machine by model and serial number in the John Deere Parts Catalog, or give our parts counter your serial number and we will find it for you.
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