Understanding the role of the AdBlue warning light in recent vehicles

Since the introduction of the Euro 5 standard in 2011, most new diesel vehicles have been fitted with a selective catalytic reduction (SCR) system to reduce their pollutant emissions. This system uses an aqueous urea solution called AdBlue® to transform harmful nitrogen oxides into harmless gases. Vehicles fitted with this system have an AdBlue® warning light on the dashboard to inform the driver of the level of AdBlue. But what role does this warning light really play in recent vehicles?

How does the AdBlue warning light work?

The AdBlue warning light comes on when the AdBlue level is low. In general, it comes on when there are around 2,400 km of range left before the AdBlue® tank is empty. When the light comes on, a warning message also appears on the dashboard.

A lire aussi : How Does Consumer Data Privacy Differ in Online Platforms vs Traditional Retail?

For added warning, a text message also appears on the vehicle's dashboard. This specifies the estimated distance remaining before refuelling with AdBlue is imperative. As this theoretical distance decreases, the reminders intensify to encourage the driver to take action quickly.

If no action is taken, the light will flash insistently when the tank is really empty. At this point, a final message warns that the vehicle will not be able to restart after the engine has been switched off unless AdBlue is added. Without this refuelling, the pollution control systems will automatically lock up, preventing the vehicle from restarting in order to limit excessive pollutant emissions. It is important to heed these warnings before turning on the procedure for switching off the AdBlue light.

Cela peut vous intéresser : 10 ways in which chatbots can help in medical decision-making

Importance of the AdBlue warning light

It is important not to ignore the AdBlue warning light. If the AdBlue tank is empty, the vehicle may go into reduced operating mode, which can lead to a loss of power and performance. In some cases, the vehicle may even refuse to start.

Switching to reduced operating mode

The SCR system deactivates, resulting in a significant loss of engine power and performance. You may no longer be able to overtake or have difficulty maintaining your speed on the motorway.

Total vehicle stoppage

In the most extreme cases, the vehicle can lock up and refuse to start until the AdBlue tank is topped up. This can leave you stranded in an embarrassing or dangerous situation.

Degradation of the SCR system

Driving with too low a level of AdBlue® can damage the SCR system, leading to expensive repairs.

Protecting the environment

The SCR system, of which the AdBlue® warning light is a key component, plays a crucial role in reducing pollutant emissions from diesel vehicles. By converting harmful nitrogen oxides into harmless gases, it helps to protect air quality and combat climate change.

Refilling with AdBlue

Refilling the AdBlue® tank is a simple operation that can be carried out at most service stations and car garages. There are also AdBlue® top-up kits available on the market, which allow the tank to be refilled at home.

Act now

As soon as the warning light comes on, it is advisable to take the utmost care to top up with AdBlue. AdBlue is available in cans from most service stations, car dealerships and some supermarkets. Once you've located the AdBlue tank (usually near the fuel trap), all you have to do is pour in the right amount of liquid. It's easy to do, and resets the warning light.


The AdBlue warning light is an important tool for ensuring that your diesel vehicle fitted with an SCR system is working properly. By paying attention to the warning light and refuelling with AdBlue regularly, you can help to reduce your vehicle's pollutant emissions and protect the environment.