We advise you to take the vehicle to a mechanic. Provided the liquid has not been diluted in some way with water or another liquid after purchase, then all our AdBlue® is within specification and cannot leave the factory out of specification. For every batch of AdBlue® we make, we hold a retained sample of the liquid for its entire shelf life. This allows us to check any batch for purity at any time. This warning usually happens on older vehicles and is due to the sensors ageing