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Diesel Exhaust Fluid (DEF) must be kept out of children's reach, to avoid serious injury or death.


Read the label for safety precautions when using DEF, to avoid injury.


DEF must be stored in the original container, in a cool, dry, and well-ventilated area. Observe the manufacturer's storage and handling recommendations.


DEF has a strong odor and can stain clothing or upholstery. Take care not to spill the fluid when performing a top-up procedure. In the event of spillage, rinse immediately with clean water.


When refilling, make sure that the correct specification of DEF is used. Use of the incorrect fluid can result in serious damage to the vehicle. In this situation, do not start the engine. Contact a retailer/authorized repairer immediately.


Do not overfill the DEF tank, as damage to the DEF system may occur.


Do not use commercial vehicle DEF dispensing nozzles. The vehicle's DEF system is not designed to be refilled under these higher pressures. The flow-rate of these pumps can result in serious damage to the vehicle.

Vehicles with a diesel engine have a tank containing Diesel Exhaust Fluid (DEF). DEF is used to make sure that correct exhaust emissions are achieved. DEF is also known as AdBlue®, AUS 32, and ARLA 32. AdBlue® is a registered trademark of the Verband der Automobilindustrie e.V. (VDA).

Dependent on the current geographical location, correct use of the DEF system may be a legal requirement. Running the vehicle without the correct specification of DEF may be a criminal offense. Always use the correct DEF specification, and the correct quantity of DEF. See LUBRICANTS AND FLUIDS, and also see CAPACITIES.

The consumption of DEF can vary greatly. An average of 6 US pints (2.8 L) of DEF is used per 1 000 miles (1 600 km), but this consumption rate can be significantly affected by driving style, road and weather conditions.

The distance until the DEF tank is empty can be viewed in the vehicle's instrument panel:

  1. Switch on the ignition. See SWITCHING ON THE IGNITION.

  2. Press the OK button repeatedly on the steering wheel control until Driver Assistance is displayed.

  3. Using the down arrow button on the steering wheel control, scroll down to highlight Vehicle Information.

  4. Press the OK button to confirm selection.

  5. Scroll down to highlight Next Service.

  6. Press the OK button to confirm selection. The Diesel Exhaust Fluid range is then displayed.

The instrument panel displays a series of messages when the DEF level becomes low:

  • The first message states that the DEF level is at a level where a top up is advised.

  • The second message is accompanied by an AMBER warning icon and states to refill the DEF tank.

  • The third message starts a countdown of the distance remaining until the DEF tank is empty, after which the vehicle will fail to start.

  • The final message is accompanied by a RED warning icon and is displayed when the distance remaining is zero and states that no further restarts are possible until DEF is added to the tank.


When the DEF level becomes low, a notification message displays in the instrument panel. Refill the DEF tank at the earliest opportunity. A retailer/authorized repairer can be contacted to arrange a full DEF refill.

To perform a full DEF system refill, it is recommended to contact a retailer/authorized repairer. If required, DEF can be added to the tank by following the top-up procedure.

Two standard-sized, non-drip refill bottles, each containing 4 US pints (1.9 L) of DEF, is the minimum amount required to restart the engine. Refill bottles are available from a retailer/authorized repairer.

To perform a DEF top-up procedure:


Turn the tank filler cap counter-clockwise to remove.

  1. Place the refill bottle over the tank filler cap aperture and turn clockwise, until locked into position.

  2. Press the base of the refill bottle, until all of the fluid has completely drained into the tank.

  3. Turn the refill bottle counter-clockwise and remove.

  4. Repeat the procedure with the second refill bottle.

  5. Replace the tank filler cap and continually turn clockwise until hand tight.

If a DEF warning lamp, or a message, illuminates with a red warning icon, seek qualified assistance at the earliest opportunity. The possible events for this include DEF system malfunctions, incorrect fluid, and fluid quality. See DIESEL EXHAUST FLUID (DEF) (RED), and DIESEL EXHAUST FLUID (DEF) (AMBER).


In extremely low temperatures below 14°F (-10°C), DEF may freeze in the tank, making refilling difficult. Move the vehicle into a warmer environment, e.g., a garage. Raise the ambient temperature, in order to thaw the DEF, before attempting to top up. In these conditions, it may take up to 1 hour of driving before the low DEF message extinguishes.


When starting and stopping the engine, operation of the DEF pumps may be heard, but this is no cause for concern.


The check engine (amber) warning lamp may illuminate after a refill. In this event, start the engine, run for approximately 30 seconds, and then switch off the engine. Do this three times in succession.