Jeep Wrangler: Diesel Exhaust Fluid / Adding Diesel Exhaust Fluid

The DEF gauge (located on the instrument cluster display) will display the level of DEF remaining in the tank.


Driving conditions (altitude, vehicle speed, load, etc.) will affect the amount of DEF that is used in your vehicle.

DEF Fill Procedure


For the correct DEF fluid type.

  1. Remove cap from DEF fill inlet (located in fuel door).

    Jeep Wrangler. Adding Diesel Exhaust Fluid

    Fuel and Diesel Exhaust Fluid Fill Location

    1. Diesel Fuel Filler

    2. Diesel Exhaust Fluid Filler

  2. Insert DEF fill adapter/nozzle into DEF fill inlet.


    • The DEF gauge may take up to five seconds to update after adding a gallon or more of Diesel Exhaust Fluid (DEF) to the DEF tank. If you have a fault related to the DEF system, the gauge may not update to the new level. See an authorized dealer for service.
    • The DEF gauge may also not immediately update after a refill if the temperature of the DEF fluid is below 12°F (-11°C). The DEF tank heater will possibly warm up the DEF fluid and allow the gauge to update after a period of run time. Under very cold conditions, it is possible that the gauge may not reflect the new fill level for several drives.
    • Excessive overfilling of the DEF tank can result in a MIL lamp/fault code and inaccurate level readings.

    Refilling With Nozzles

    You can fill up at any DEF distributor.

    Proceed as follows:

    • Insert the DEF nozzle in the filler, start refilling and stop refilling at the first shut-off (the shut-off indicates that the DEF tank is full). Do not proceed with the refilling, to prevent spillage of DEF.
    • Extract the nozzle.

    Refilling With Containers

    Proceed as follows:

    • Check the expiration date.
    • Read the advice for use on the label before pouring the content of the bottle into the DEF tank.
    • If systems which cannot be screwed in (e.g. tanks) are used for refilling, after the indication appears on the instrument panel display Ú page 110 fill the DEF tank with no more than 2 Gallons (8 liters).
    • If containers which can be screwed to the filler are used, the reservoir is full when the DEF level in the container stops pouring out. Do not proceed further.


    • To avoid DEF spillage, and possible damage to the DEF tank from overfilling, do not “top off” the DEF tank after filling.
    • DO NOT OVERFILL. DEF will freeze below 12ºF (-11ºC). The DEF system is designed to work in temperatures below the DEF freezing point, however, if the tank is overfilled and freezes, the system could be damaged.
    • When DEF is spilled, clean the area immediately with water and use an absorbent material to soak up the spills on the ground.
    • Do not attempt to start your engine if DEF is accidentally added to the diesel fuel tank as it can result in severe damage to your engine, including but not limited to failure of the fuel pump and injectors.
    • Never add anything other than DEF to the tank – especially any form of hydrocarbon such as diesel fuel, fuel system additives, gasoline, or any other petroleum-based product. Even a very small amount of these, less than 100 parts per million or less than 1 oz. per 78 gallons (295 liters) will contaminate the entire DEF system and will require replacement. If owners use a container, funnel or nozzle when refilling the tank, it should either be new or one that is has only been used for adding DEF. Mopar® provides an attachable nozzle with its DEF for this purpose.
  3. Stop filling the DEF tank immediately when any of the following happen: DEF stops flowing from the fill bottle into the DEF fill inlet, DEF splashes out the fill inlet, or a DEF pump nozzle automatically shuts off.
  4. Reinstall cap onto DEF fill inlet.

    Diesel Exhaust Fluid Storage

    Diesel Exhaust Fluid (DEF) is considered a very stable product with a long shelf life. If DEF is kept in temperatures between 10° and 90°F (-12° and 32°C), it will last a minimum of one year...


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    Jeep Wrangler. Manual Seat Height Adjustment

    Seat Height Adjustment

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