AdBlue failure on Renault and Dacia Blue dCi: what the legal guarantee of conformity covers

On Renault and Dacia Blue dCi models including Clio, Captur, Duster and Kadjar, the P20EE fault code indicates that the SCR system is operating below its efficiency threshold. NOx emissions are not being treated sufficiently. Reported cases point to crystallization obstructing the AdBlue injector in the exhaust line. Cleaning or replacing the injector is the logical repair, but it does not always clear the code.

The warning changes the practical situation. When the anti-pollution message appears, the engine computer starts a countdown: 1000 km according to our French source, or 600 miles in the English version. At zero, the vehicle will not restart. Erasing P20EE with a diagnostic tool is not a repair. Owners report that after an independent repairer cleans or replaces the injector, the countdown can continue because the engine ECU remains locked by software, and the vehicle is then sent to a dealer for a software reset.

Two distinct guarantees

The manufacturer's commercial warranty is separate from the legal guarantee of conformity. Under consumer law, the legal guarantee of conformity is owed by the seller. It exists independently of any commercial promise. For an AdBlue failure that renders the vehicle unserviceable, this distinction matters. The first step is to identify the seller and to invoke the legal guarantee of conformity when the vehicle is not in conformity with the contract.

Hidden defects and serial defects

The legal guarantee of conformity is not the only basis. The guarantee of hidden defects is a distinct route, aimed at a design defect. If the same fault repeats across a family of vehicles, that recurrence supports the argument of a serial defect. On Blue dCi engines, a fault that recurs on the same engine family points in that direction. A software lock that prevents starting and forces a dealer intervention does not address the underlying component failure if the component itself remains defective.

Keep the file complete

Maintenance records matter. Keeping maintenance invoices deprives the seller of the argument that the failure is due to a lack of maintenance. This is useful whether you rely on the legal guarantee of conformity or on hidden-defect law.

Owners facing a repeated AdBlue fault can document the sequence: fault code, symptoms, repair attempts, countdown, and any dealer reset. The point is not to assert a cause that has not been established, but to preserve the facts that allow consumer protection and hidden-defect law to be examined.

To help build a factual record of AdBlue and Haldex failures across Europe, you can register your case at adblue-haldex.com.