What it means
This warning means the diesel exhaust fluid (also called AdBlue or DEF) is empty or low enough that the vehicle is warning of an impending no-restart condition. Red generally signals an urgent condition, but the warning level, remaining distance, and restart restriction vary by manufacturer; follow the display and owner’s manual.
What the symbol looks like: A diesel exhaust-fluid warning may show a fluid container or droplets with an exhaust or “AdBlue” message, but the symbol is not identical across vehicles.
Why it comes on
- The exhaust-fluid tank is empty
- The fluid level has fallen below the vehicle’s warning threshold
- The fluid-level sensor or its wiring is faulty
- The vehicle has detected a fault in the selective catalytic reduction system
What to do
- Read the dashboard message and check the owner’s manual for the correct fluid and filling procedure
- Refill with the specified diesel exhaust fluid as soon as safely practical
- Follow any instructions or wait time shown by the vehicle after refilling
- If the warning remains after a correct refill, or the vehicle will not restart, contact a repairer or roadside assistance
Can I keep driving?
Do not ignore this warning: the vehicle may limit operation or refuse to restart after being switched off. If it is running, go only as far as needed to refill or reach assistance, following the displayed instructions.
Symbols and colours differ between makes and models. Your owner’s manual shows the exact lights of your car.