When an AdBlue or Haldex fault appears, the first contact with the manufacturer often sets the tone for what follows. A short, factual letter does not need to be long. Its function is to put the defect on record, in writing, and to place the issue within consumer protection and hidden-defect law.
Why put the defect in writing
An AdBlue failure is not just a faulty accessory. In SCR-equipped vehicles, the system is inseparable from engine operation. Our technical file on the 1.5 BlueHDi (DV5) engine, used across Peugeot, Citroën and Opel models, notes that the entire vehicle becomes unusable by software decision. The same file discusses timing chain issues and AdBlue failures. On the Haldex side, the source covers VW, Audi, Škoda and Seat models with DSG gearboxes and all-wheel drive. There, a DSG oil change is often confused with Haldex servicing. The two systems have separate housings, separate oils and separate maintenance intervals. A service invoice that mentions only the DSG means the Haldex has not been serviced. If the Haldex has been ignored, the pump can fail before 50,000 miles. A written record helps document these facts.
What the first letter should contain
- Date the defect. State when the problem first appeared.
- Describe the defect. Explain the symptoms and the system affected: AdBlue/SCR or Haldex.
- Invoke Article 1641 of the French Civil Code. This places the letter in the framework of hidden defects.
The letter should be factual and calm. It should not allege intent or make accusations that cannot be verified. The aim is to create a dated record that can support a hidden-defect claim later. The first letter does not need to prove the whole case. It fixes the date, the description and the legal basis.
How to send it
Send the letter by registered mail with acknowledgement of receipt. Keep a copy of the letter. This creates a clear timeline. The first letter is not the whole case; it is the foundation.
Why the registry matters
Individual letters document individual cases. A registry maps the scale of these defects. If you have experienced an AdBlue or Haldex failure, register your case at adblue-haldex.com to join the collective effort.
Are you affected by this problem?
Join the national registry to document your case and defend your rights.
Register my case