Table of Contents

AdBlue, also known as Diesel Exhaust Fluid (DEF), is a diluted solution of urea and deionised water with a composition of 32.5% and 67.5%, respectively. AdBlue is used in diesel engines to reduce the emissions of harmful nitrogen oxides (NOx). Drivers fill their AdBlue systems with AdBlue to ensure an eco-friendly and lawful drive.

However, after a typical range like 2400 km, all the AdBlue gets consumed, indicated by a warning light. This warning light indicates that you should refill and adjust the system counters, which we generally call Ad Blue reset.

Let’s have a detailed overview of the Ad Blue reset and why it’s important. Lastly, we will address some general queries related to AdBlue Reset:

What is AdBlue Reset?

The adBlue system works in collaboration with the exhaust system of the vehicle. It consists of a tank, pump, and other sensors that monitor the pressure, volume, and temperature of the AdBlue while it is working in the system.

Once we refill the AdBlue in the system, its settings are adjusted so that the system can detect the parameters, like the amount volume for the newly filled amount. This adjustment process is called AdBlue Reset.

Tips for AdBlue Resetting

  1. Locate the AdBlue tank in the vehicle that can be under the hood or in the vehicle’s trunk.
  2. Keep filling the tank with AdBlue until the warning light goes off.
  3. Ignite the engine and keep it running for a few minutes to detect the new level of AdBlue.
  4. Now, switch off the engine and restart to verify if the system has recognised the new volume of AdBlue.
  5. In case of any issue, contact a professional technician to check and resolve the issue.

Why is AdBlue Reset necessary?

When there is insufficient AdBlue in the system, the system turns on a warning light. After refilling, it is mandatory to reset the system as this resetting enables the system to know about the new level of refilled AdBlue.

  • If the system is not reset, it keeps the warning light on permanently, which annoys the driver and sends a message to the engine to slow down. This limits the engine’s power and efficiency.
  • Additionally, ignoring the warning light may lead to further damage as well as a fine from vehicle regulatory authorities.
AdBlue Reset necessary

Reasons for AdBlue System Issues

Any problem with the AdBlue system is indicated by the warning light, and there are many reasons for the activation of the AdBlue warning light in your vehicle.

  • An error in the AdBlue solution delivery system.
  • Some sort of ECU glitches.
  • An error with the AdBlue sensor.
  • You have poured the wrong type of AdBlue.

How to Resolve Issues with the AdBlue Warning Light?

If you have any issues with your vehicle or its AdBlue system, you can do the following tasks to resolve the problem.

Turn on the ignition switch

A smart way to resolve this issue is to turn on your ignition switch, wait for 30 seconds, and let all your vehicle’s lights turn on. Now, switch off the ignition and again start your engine.

If the warning light is on, drive your vehicle for a few miles. This may sort out any glitch present in the system.

Battery Reset

Although it’s a primitive technique, it may work. Battery reset implies that you simply disconnect the cables from the positive and the negative terminals. Keep them disconnected for 15 minutes. Once the specific time passes, reconnect them, restart your vehicle, and monitor the progress.

Utilise A Scanner

Using a scanner can also be effective in this case. Find a suitable OBDII scanner, connect it to the OBD port, switch on the ignition and read for the fault codes to identify the issue. Resolve that key issue and switch on the ignition again to check whether the issue persists.

If none of these procedures works, then there is some serious issue with your vehicle other than minor glitches.

  1. There may be a low quantity of AdBlue in the vehicle
  2. A fault has occurred in the sensor, wiring, or AdBlue injector
  3. ECU, or Engine Control Unit, is the brain of your vehicle’s engine and is faulty.

In the case of these three problems listed above, get your vehicle inspected by an expert mechanic.

AdBlue System Issues

Some Important Questions on AdBlue


Can I run my vehicle without AdBlue?

It is not legal to run your diesel engine without AdBlue. Not only will it affect the SCR system’s ability to reduce NOx emissions, but also will it affect the engine’s performance. Apart from this, you may be penalised by the relevant authorities for violating the protocols.

Is AdBlue damaging to my engine?

AdBlue is a urea and deionised water-based liquid solution introduced into the exhaust stream of an SCR in the engine. AdBlue does not directly react with the fuel or participate in the combustion process; however, it reacts with the engine’s emissions.

On these grounds, we can say that AdBlue is safer for the engines having an SCR system that assists engines in enhancing their efficiency and clean emissions.

It is noteworthy to remember that adding AdBlue to engines that do not have an SCR system can be harmful to the engine.

What if the AdBlue mixes with the diesel in my engine?

If the AdBlue mixes with the diesel, it will form a thick layer in the bottom of the tank. This thick layer will clog the pipes and other parts of the engine. Moreover, it will promote corrosion in certain engine parts, which can be damaging.

What if I use water instead of AdBlue in my vehicle?

Using water in place of AdBlue is not recommended in any case, as the chemical makeup of water differs from that of AdBlue. And it is incapable of reducing harmful emissions from the fuel. Additionally, adding water will affect your engine’s performance, and the environmental agency will fine you.


AdBlue is an important liquid that significantly reduces the harmful NOx emissions from diesel engines, enhancing its performance and life. It is the AdBlue Reset system that contains the AdBlue and processes it in coherence with the exhaust system for an efficient functioning of the engine.

Usually, this system develops glitches that can be due to less amount of AdBlue or some other technical problem with the system itself. These issues are indicated by the warning light.

Addressing the activation of the warning light demands AdBlue resetting. However, at times, the warning light remains on despite AdBlue resetting. This can be due to several reasons. To sort out the issue, it is recommended to visit an expert mechanic.

We at Reidy Remaps are skilled and well-equipped to sort all types of problems related to AdBlue resetting. Do not ignore your AdBlue warning light and reach us, get your issue resolved and enjoy a smooth ride in your car.

Feel free to contact us