A Volkswagen engineer was sentenced Friday to 40 months in prison for his role in the diesel emissions cheating scandal, which severely tarnished the German automaker’s reputation.

US District Judge Sean Cox issued the sentence in a Detroit court against 63-year-old James Liang, who was also fined $200,000, Xinhua reported.

Liang has been cooperating with U.S. authorities and pleaded guilty last year to a charge of conspiracy.

“Your cooperation and regret is noted, but it doesn’t excuse your conduct,” Cox told Liang.

The judge said Liang was “an important and key player in a very serious crime,” who helped devise software that cheated emissions tests.

The illegal software was designed to turn on emissions controls to pass government tests and turn them off while on the road. Nearly 600,000 diesel vehicles were reportedly tampered with over the past decade.

Besides Liang, six other current and former Volkswagen executives have also been indicted. The German automaker was forced to pay tens of billions in fines and civil penalties.