How To

Manage Your DEF

Did you know your diesel exhaust fluid needs to be monitored on a regular basis, just like your oil or windshield fluid? Check out our handy How-To video to learn how to manage your DEF fluid, where to buy it, and more.

If you have any questions about the procedures covered in this video, please reach out to our service and warranty department at

To learn more about taking care of your van, check out our How-To video series here.

*Outside Van is not responsible for damage resulting from improper winterization. This serves only as a guide to basic procedures.

DEF stands for Diesel Exhaust Fluid. During engine operation small quantities of the fluid are injected into the exhaust stream turning smog-inducing NOx into harmless oxygen, water, and nitrogen. Your diesel exhaust fluid needs to be monitored on a regular basis, just like your oil or windshield fluid. Maintenance regularity is tied to your fuel efficiency, which varies from van to van.

Even though DEF is classified as non-hazardous by the EPA, try to avoid contact. In case of a spill, rinse the area with clean water and consult a doctor if necessary. Also, do not open your DEF cap at high temperatures due to the release of potential ammonia vapors.

Now with all the warnings out of the way, filling your DEF is quick and easy.

To add more DEF

  1. Remove the key from the ignition.
  2. Pull the hood release latch located to the left of your brake pedal.
  3. Close all vehicle doors so ammonia vapors can’t enter the vehicle.
  4. Lift the lever under your hood gain access to your engine.
  5. Then locate the fill port. A majority of the time the cap is marked. Turn the cap counter-clockwise to remove.
  6. Fill the tank via the filler neck until the DEF level can be seen in the neck.
  7. Once finished, replace the filler cap and turn clockwise until tight.

Even if it doesn’t look like you’re running low, it’s always best to fill up before long trips. An amber warning light will appear when levels drop below 10%. Don’t rely solely on this system. Without proper maintenance your vehicle has the potential to go into limp mode and not operate correctly.

You can purchase DEF at most auto supply stores and gas stations. Some gas stations even have it at the pump.

DEF should not be stored in direct sunlight. Ideal storage is in a cool, dry ventilated location around 77°F. Extreme storage temperatures will not affect the quality of the DEF, but it will impact its shelf life. When stored between 12°F and 86°F, DEF has a shelf life of up to two years.