Germany's KBA (Kraftfahrtbundesamt) has placed a registration ban on the Porsche Cayenne Diesel due to the discovery of what it describes as suspect emission manipulation software.
The ban, confirmed by German transport minister Alexander Dobrindt on Thursday, comes after KBA testing revealed the two Porsche models are fitted with software that manipulates CO2 emissions by switching to a so-called warm up strategy mode when it detects they are undergoing testing on a rolling road – the process providing them with a lower CO2 rating than that achieved otherwise.
The Cayenne Diesel and Macan S Diesel both run an Audi-developed and produced turbocharged 3.0-litre V6 diesel engine – the same unit used by Audi in a raft of different models, including the A4, A6, A8, Q5 and Q7. In the Cayenne Diesel, the Audi V6 diesel develops 262bhp and is claimed to return 6.6L/100km (42.8mpg) on the combined European consumption test cycle for average CO2 emissions of 173g/km.
As well as placing an immediate ban on the registration of the Cayenne Diesel, the KBA has also order a recall of up to 22,000 vehicles already sold in Germany.
The Cayenne registration ban comes after tensions between Porsche and Audi were strained following comments made by Porsche union boss, Uwe Hueck, on Monday.
In a pointed attack on Volkswagen sister company Audi, Porsche’s Hueck said: “We feel deceived by Audi. The supervisory board should fire the management."
Porsche released the following statement: "Porsche has detected irregularities in the engine control software during internal investigations and has actively pointed this out to the Kraftfahrtbundesamt (KBA), German Federal Motor Transport Authority. The irregularities are not related to the transmission control software. Corrections by means of a software update within the scope of a recall were agreed with the authority.