According to German paper Bild am Sonntag, investigators found engine management function called “Slipguard”, programmed to recognize whether the car was being tested in a laboratory.
Citing official documents, the paper also claims that another functioned called “Bit 15” was there to switch off emissions cleaning after about 16 miles (25 km) of driving. Apparently, the software helped reduce the application of AdBlue fluid, which helps eliminate harmful exhaust gases, resulting in some Mercedes diesels emitting NOx fumes up to 10 times higher than the legally permitted levels.
The German newspaper report cited e-mails from Mercedes‘ own engineers who questioned whether these software functions were legal. According to Autonews, a spokesman for Daimler declined to comment on the findings, stating that the automaker was fully cooperating with U.S. authorities.
“The authorities know the documents and no complaint has been filed,” said the spokesman. “The documents available to Bild have obviously selectively been released in order to harm Daimler and its 290,000 employees.”
Back in 2016, a class action lawsuit was filed against Mercedes by owners of their diesel-powered cars in the U.S., claiming that the automaker “deceived customers by knowingly programming its BlueTEC vehicles to release illegal levels of emissions in virtually all real world driving conditions.”