Last Thursday German Transport Minister Alexander Dobrindt accused Porsche of utilizing a "defeat device" in certain Cayenne Diesel models (all utilize the 3.0 liter TDI VW Engine). This, in turn, forced Porsche to recall nearly 21,500 models across all of Europe (7500 or so of the affected Cayennes are located in Germany). Essentially, inspectors found that a certain software (or "defeat device") allowed the Porsche to cheat on normal emission testing while still producing more emissions than allowed during every day driving.
In addition to the recall, Germany imposed a "registration ban" on new models until such a time as Porsche can fix this issues. This means that those Cayenne TDI's still in production can not be sold or driven on the road. While the Cayenne's in question use the same 3.0 V-6 engine that is in the middle of the "Dieselgate" probe we're all so familiar with, there will be no buy back program in Europe like there is here in the U.S. Instead, Dobrint and Porsche have both said a recall will work as the issue centers around a piece of software that can be removed or reconfigured.
Porsche's Official Statement
Porsche sent out a press release that said, "Subject to approval of the proposed technical software update by the KBA (the German Federal Motor Transport Authority), the recall is expected to begin in autumn 2017 and will be completed as soon as possible. The vehicle owners will be contacted directly by their responsible Porsche partner. The visit to the workshop, which will take around one hour, will be arranged as soon as possible and will be handled free of charge."
Independently of the agreed recall, Porsche is continuing to carry out internal inspections of its vehicles to identify any further potential optimizations. In addition, the company is still working in close cooperation with the authorities, especially the KBA, in all matters.