VW and clean diesel’s false promise.

Thanks to the work of investigators in the United States, and tardy new efforts in Europe, the full extent of the lies and cheating that enabled automobile manufacturers to sell diesel vehicles that were anything but “clean” is coming to light. Volkswagen remains at the heart of the scandal to install illegal software that lowered dangerous nitrogen oxide emissions to U.S. legal limits for test purposes, then allowed them to jump back up to levels up to 40 times greater during normal driving.

But new revelations potentially implicate German automakers Daimler and BMW in illegal collusion with VW to hold down the prices of crucial technology, including emissions equipment. The government of the German chancellor, Angela Merkel, and the European Union are also guilty of tolerating gaping loopholes in European regulations that allowed automakers to pollute with impunity in Europe.

The cost of such cynical chicanery to the public’s health has been high. In March, a study by scientists at the Massachusetts Institute of Technology estimated that 1,200 people in Europe could die prematurely due to harmful emissions that VW failed to limit. Volkswagen’s argument is that those higher emissions were not illegal in Europe, and therefore it owes no compensation there on the order of the $22 billion in government fines and settlements it has been forced to pay in the United States, where the scandal first broke in 2015.

On Friday VW’s Audi division followed Daimler’s and BMW’s plans to upgrade emissions software on diesel vehicles across Europe. They have good reason to act: The public is fast losing faith in the integrity of German automakers, and high pollution has prompted several European cities to consider banning or limiting diesel vehicles.

The legal toll is also mounting. On Tuesday, Volkswagen executive Oliver Schmidt, arrested in January in Miami, agreed to plead guilty in federal court next week to covering up the fraud. Another VW executive, James Robert Liang, has already pleaded guilty to charges related to the cheating. And, earlier this month, the VW executive Zaccheo Giovanni Pamio was arrested in Munich on charges related to emissions fraud. An Italian, Mr. Pamio is not protected from extradition to the United States by German law.

To reduce air pollution and meet obligations under the Paris climate agreement, the British government announced on Wednesday that it will ban all new gasoline and diesel vehicles by the year 2040, following France’s announcement earlier this month to do the same. Volvo announced this month it will make only electric or hybrid vehicles after 2019. While these moves herald the end of diesel and, quite possibly, the internal combustion engine, Europe’s dirty air means that carmakers must begin now to make their vehicles less polluting.