Mercedes-Benz has equipped diesel models with software which may have cheated emission tests, according to a report published by German Newspaper Bild am Sonntag.
According to Bild am Sonntag, US investigators have found an engine management function called “Slipguard” that recognised whether the car was being tested in a laboratory or on the open road.
The “Bit 13” function switches the diesel engine to “dirty mode” once it emits 16 grams of NOx- the length of the US highway test cycle.
Mercedes-Benz is also suspected of using the “Bit 14” software function which switches the engine into “dirty mode” when used under certain temperatures and lengths of time. This function is ideally suited to cheating the FTP-75 warm test cycle.
Another function named “Bit 15” deactivated emissions cleaning after about 16 miles (25.6km) of driving.
The software applications worked together to reduce or regulate the application of AdBlue fluid that helps to eliminate harmful exhaust gasses. The software could mean that Mercedes-Benz diesels emitted NOx pollutants up to 10 times higher than legal levels.
The manipulative software programs allegedly used by Mercedes-Benz in select Diesel vehicles would allow the models to pass strict US emission tests by running in a faux ultra-clean state for a limited period.
The allegations are reminiscent of the Volkswagen Dieselgate scandal in 2015 when it admitted to installing software on over 580,000 US vehicles that allowed them to emit up to 40 times the legally permitted amount of harmful emissions.
Speaking to Bloomberg via email, Daimler spokesman Joerg Howe alleges that the documents released by Bild am Sonntag had “selectively been released in order to harm Daimler and its 290,000 employees” and that authorities were already aware of the documents and no complaints have been filed.
Mercedes-Benz are yet to officially comment on the allegations.