Mercedes BlueTEC diesels use a sophisticated SCR system with multiple NOx sensors — and the more sensors a system has, the more there is to fail. Sprinter vans and C-Class saloons make up most of the Mercedes work we see.
Affected Mercedes models
Sprinter 2.1 & 2.2 CDI (906 and 907)
Vito & V-Class 1.6 / 2.1 CDI
C-Class, E-Class and S-Class BlueTEC diesels
GLC, GLE and ML BlueTEC SUVs
Citan (shared with Renault Kangoo)
Typical warnings
'AdBlue: refill — no start in 800 miles' or a similar countdown in the instrument cluster.
'Check AdBlue — see owner's manual' with a yellow warning triangle.
'Emission control — visit workshop' plus limp mode.
Cold-weather no-start warnings caused by AdBlue tank heater failure.
Why Mercedes systems fail
Sprinters spend their lives on short delivery runs, which never get the SCR system fully up to temperature — the fastest route to urea crystallisation.
The delivery module and tank heater are exposed to road salt and water, and the wiring connectors corrode.
Genuine Mercedes NOx sensors are among the most expensive on the market, which is why many owners choose a permanent removal instead.
Frequently asked questions
How much is a Mercedes Sprinter NOx sensor?＋
Genuine sensors are typically £300–£600 each before fitting and coding, and the Sprinter uses more than one. That's why permanent removal is often the more economical route.
Do you cover Sprinter fleets?＋
Yes. We work mobile and can process several vans at one site in a single visit to keep your downtime to a minimum.