AdBlue / SCRTTTOKEN0FIN
Mercedes OM654 AdBlue System
OM654 AdBlue system faults can create countdown warnings and expensive diagnosis, so buyers should check SCR readiness, NOx data, and repair history.
Repair difficulty
Moyen
Estimated cost
Medium to high depending on sensor/tank/module involvement.
Affected models and engines
- Modern Mercedes diesel models using OM654 engines and SCR/AdBlue emissions systems
Symptoms
- AdBlue countdown
- Check-engine light
- No-start warning
- NOx efficiency faults
Why it fails
- NOx sensors, dosing units, tank heaters, and software all interact.
- Short trips and poor battery health can complicate diagnosis.
- Cleared codes can return after a full drive cycle.
Checks before buying
- Scan SCR and NOx modules with Mercedes-capable diagnostics.
- Check for countdown history and recent code clearing.
- Verify AdBlue tank, injector, and NOx sensor invoices.
- Drive long enough for readiness checks.
Fault codes to investigate
Fault codes guide diagnosis; they do not confirm a part without live data, inspection, service history, and repeat testing.
Related research
Continue your research
Move from brand context to exact model, powertrain, fault-code, and buying-checklist evidence.
Aide à l'acheteur
Request a used-car risk review
Envoyez-nous le modèle, l'année, le moteur et le kilométrage. Nous vous aiderons à identifier les principaux risques avant d’acheter.
Points faibles connus du moteur et de la boîte de vitesses.
Codes d'erreur et symptômes à vérifier.
Questions d'inspection avant négociation.
Il s’agit d’un guide pour l’acheteur, et non d’une inspection mécanique à distance ou d’une garantie. Vérifiez toujours la voiture en personne avec les diagnostics et les dossiers d'entretien.