The German government is ordering car maker Daimler to immediately recall 238,000 vehicles equipped with software that turns off emissions controls under certain conditions.
Transport minister Andreas Scheuer spoke after a meeting with Daimler CEO Dieter Zetsche.
Mr Scheuer said Daimler was willing to work "with co-operative transparency" with the government and "at maximum speed".
The affected vehicles include the Mercedes-Benz Vito delivery van and the Mercedes GLC 220d and C220d.
Europe-wide, some 774,000 vehicles are affected.
Diesels have been under heavy scrutiny since US authorities caught Volkswagen using illegal engine control software that turned off diesel emission controls in everyday driving.
Subsequent investigations showed that other automakers had exploited European regulatory loopholes to limit the conditions under which emission controls work.