Duh throws bmw use of shutdown device

Duh throws bmw use of shutdown device

With a roughly applied attempt, the german environmental help (DUH) wants to detect the automaker BMW the use of a shutdown in at least one case. The DUH had notified after tests with a 2016 built BMW 320D touring with automatic, the exhaust values suggested that BMW used a so-called shutdown device. Tests in the strain operation had significantly higher exhaust values than in the laboratory. However, this is not enough as proof yet.

Prejected prompted

BMW has prompted the burrs of the DUH immediately. "There are no activities and technical precautions in the BMW group to influence the prufmodus for the collection of emissions," said the group on monday evening (4. December 2017) on request with. "Limitally applicable that BMW vehicles comply with and are not manipulated each of the leasher law."BMW stressed, the TUV sud had already tested a technically identical model in 2015 while not detecting any procedures. The DUH wants the results on tuesday (5. Introduce december 2017) in berlin. Previously, the ZDF broadcast had wiso as well as the daily newspaper daily mirror (edition of 5. December 2017) reported.

When the DUH is experienced, it was found that exhaust prere relief is switched off above 3500 / min. This increases the nitric oxide values (nox) strongly. Why, BMW did not want to tell. In addition, in a test on the strain, the values in the exact descendant of the NEFZ was just above the permissible limit value. If, according to the DUH, was only minimally faster, the nox values rose sharply.

In the statement "slightly faster" but be careful, because on the one hand this is a vague statement. On the other hand, it is normal for vehicles with storage cats that the values increase at high load. A memory cat can not respond directly to this nox quantity. What remains is to increase the gas transit rate jerk. This makes the combustion minimal "worse", which lowers the temperature in the combustion chamber. This also sinks the nox amount in the raw exhaust.


BMW currently relies up to the 3rd and its derivatives in the diesel models on a storage device. It is active with comparatively small exhaust temperatures and costs less. The elaborate exhaust aftertreatment with storage cap plus a SCR-CAT and adblue injection BMW works only from the 5er. One of the advantages of a SCR cat is that it can react more flexibly. For a higher nox component in the raw exhaust gas can be injected accordingly more adblue – if the manufacturer defines this.

If a shutdown device is actually used at BMW, it works differently than volkswagen. There was a prudent detection, which is not illegal for itself, used to manipulate exhaust values. The american international council ON clean transportation (ICCT) ultimately came to the legible, because the exhaust gas values determined in the laboratory will love under no circumstances on the strain. At least that you can not say BMW. The examined 320d also reached on the strain values, which were similar to those in the laboratory, if only in the framework specified by the legislature.