The software has been found to halve the amount of nitrogen oxides (NOx) emissions until the steering wheel is turned more than 15deg, according to the German Transport Ministry.
The Ministry has given Audi ten days to come up with a solution to the issue and a plan to refit the cars. Audi had already launched a recall for the 24,000 cars on Thursday. The affected A7 and A8 examples were built between 2009 and 2013, and around 14,000 of these were sold in Germany.
Since then, the brand and the Volkswagen Group as a whole has shifted focus to low and zero-emissions cars, with Audi announcing only yesterday its plans for three new electric models within the next year, and the gradual electrification of its core range in the coming years.
Audi has released the following statement in relation to the findings: "The latest analyses of A7 and A8 automobiles of model years 2010 through 2013 with V6 and V8 engines certified according to the EU5 emission standard have revealed that in certain situations, NOx emissions are between 20% and 100% above the limit.
The reason is that in some situations, engine speed is unfavourably influenced by the transmission software, which can have a negative impact on the engine’s emissions. A recall is likely to start in July 2017. As only a software update will be installed, the time required for the work on the cars will be about 30 minutes.