Audi A6 Typ 4G: Selective catalytic reduction (AdBlue/DEF)

General information

Applies to: vehicles with selective catalytic reduction

In vehicles with selective catalytic reduction, a urea solution (AdBlue/DEF) is injected into the exhaust system before a nitrogen oxide catalytic converter to reduce nitrogen emissions. The urea solution is known as AdBlue or DEF (Diesel Exhaust Fluid). AdBlue is used in the following.

The AdBlue is carried in a separate tank in the vehicle.

The AdBlue usage accounts for approximately 0.5% to 2.5% of the diesel fuel that is used.

When a message about refilling the AdBlue appears in the instrument cluster display, you must refill the AdBlue yourself or have it refilled by an authorized Audi dealer or authorized Audi Service Facility.

Tips

• The instrument cluster display indicates the distance remaining that can be driven. If the AdBlue tank is completely empty, the engine will not start again after the ignition is switched off.
• AdBlue is required by law to operate this vehicle.

Messages in the instrument cluster display

Applies to: vehicles with selective catalytic reduction

The display indicates if the AdBlue level is low or if there is a system malfunction.

AdBlue level low

You will be informed if the AdBlue in the tank drops below a certain level.

Please refill AdBlue. Range x mi (km)

This message appears when there is only enough AdBlue left to drive the distance indicated in the driver information system. Fill the AdBlue.

Refill AdBlue! Cannot start engine in x mi (x km)! See owner's manual

This message appears when there is only enough AdBlue left to drive the distance indicated in the driver information system. Fill the AdBlue. Otherwise the engine will not start again if you stop it once the distance indicated has been driven. You can also check the remaining distance in the onboard computer.

Refill AdBlue! No restart! See owner's manual

This message appears when the AdBlue tank is empty. Fill the AdBlue. Otherwise you will not be able to start the engine again once you stop it.

The AdBlue must be refilled when the amount in the tank has reached the minimum level.

Incorrect filling/system malfunction

A message appears if the AdBlue tank was filled with a fluid other than AdBlue and the system has detected that the tank was filled incorrectly, or if there is a system malfunction.

AdBlue: system fault. No restart in x mi (x km) See owner's manual

This message appears when it is only possible to drive the distance indicated in the driver information system. Drive to the nearest authorized Audi dealer or authorized Audi Service Facility to have the malfunction corrected. Otherwise the engine will not start again if you stop it once the distance indicated has been driven.

AdBlue: System fault No restart! See owner's manual

This message appears if the system has detected that the tank was filled incorrectly or that there is a malfunction. Drive immediately to the nearest authorized Audi dealer or authorized Audi Service Facility to have the malfunction corrected.

Otherwise you will not be able to start the engine again once you stop it.

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