BERLIN/FRANKFURT (Reuters) - Germany's Transport Ministry quizzed Daimler DAIGn.DE Chief Executive Dieter Zetsche on Monday over how many Mercedes-Benz vans and cars need to be fixed after a regulator said it had found illegal software in one of its models.

FILE PHOTO: Daimler CEO Dieter Zetsche speaks during a world premiere for the new Mercedes Benz A-Class L Sedan in Beijing, China, April 24, 2018. REUTERS/Damir Sagolj/File Photo

The luxury carmaker was summoned to a closed-door meeting to answer questions about software devices found in Mercedes-Benz vans by Germany’s KBA motor vehicle authority.

Daimler was last week ordered by KBA to recall Vito vans fitted with 1.6 liter diesel engines because it said they breached emissions rules. Daimler has said it will appeal against KBA’s decision to classify the software as illegal and contest its findings in court if necessary, although it said it was cooperating fully.

German Transport Minister Andreas Scheuer said Daimler had been given until June 15 to come up with a solution to the Vito delivery van’s emissions issues following “an in-depth exchange about highly complex technical questions”.

“At a further meeting in 14 days, concrete results will be on the table,” Scheuer added in a statement.

Asked how the meeting went, Zetsche told Reuters: “It was a good discussion. We will see each other again in 14 days.”

Global carmakers are facing a regulatory clamp-down since Volkswagen VOWG_p.DE admitted to deliberately cheating diesel emissions tests in 2015.

Regulators are now focusing on narrowing the gap between pollution levels “on the road” when compared to exhaust emissions measured during testing.

Germany’s Transport Ministry said the Vito had been equipped with a software device which manipulated the an emissions filtering system which relies on injecting a urea-based liquid to help neutralize nitrogen oxide emissions in exhaust fumes.

CRIMINAL INQUIRY

Some Mercedes-Benz models, including the Vito, use diesel engines supplied by Daimler's partner Renault RENA.PA. French prosecutors opened a probe into Renault in January 2017 after the country's consumer watchdog DGCCRF found engine software deactivated anti-pollution functions.

Daimler has previously said Mercedes vehicles being scrutinized by KBA were fitted with a Renault supplied OM622 engine, which had been used in around 1,000 Mercedes-Benz Vito tourer models in Germany.

Under European rules, carmakers rather than suppliers are responsible for the legality of road certification of each model they sell, even if engines and software were supplied by third party.

Daimler and Robert Bosch, which supplies engine management systems, are both being investigated by criminal prosecutors in Stuttgart.

Asked whether French prosecutors were being briefed as part of the Mercedes probe, the Stuttgart prosecutor’s office said only that it was in touch with foreign authorities.

Renault declined to comment.

Daimler said on Monday that no diesel engines supplied by Renault were used in Mercedes-Benz vehicles sold in the United States, where the discovery of illegal software devices carries far higher penalties than in Europe.

European rules on using software to manage exhaust emissions filtering systems are more lax than in the United States, allowing carmakers greater leeway to switch off exhaust filtering systems if “engine damage” can be reduced as a result.

German newspaper Bild am Sonntag, without citing sources, said regulators are probing around 40,000 Mercedes-Benz Vito vans and 80,000 C-Class models for possible software that allowed them to emit excess pollution without detection.

European carmakers had invested heavily in diesel engines, which produce less carbon dioxide but more of other pollutants blamed for causing respiratory disease than petrol engines.

However, German cities are now entitled to ban older diesel vehicles from streets to bring air pollution levels in line with European Union rules.