Volkswagen is facing huge fines, its reputation is in tatters, and now CEO Martin Winterkorn has stepped down. The company cheated diesel emissions tests in the US for seven years. It did so through a clever piece of software that could identify when it was being tested and reduce harmful exhaust so it looked as if the cars met requirements, when in fact they didn’t. Volkswagen was caught by independent testing carried out by a clean-air advocacy group, The International Council on Clean Transportation, which tested the cars because it thought they were such a great example of how diesel could be a clean fuel. Here’s a rundown on what happened and when.
In 2008, tougher emissions rules come in to force.
Most car manufacturers use a urea-injection system, often called AdBlue, which uses a chemical catalyst to make sure unburnt fuel doesn’t get into the exhaust. But VW says it can meet the regulation without the AdBlue system on many of its cars.
In 2013, The International Council on Clean Transportation teams up with West Virginia University for a study on the Volkswagen diesel cars.
“We had no cause for suspicion,” John German, from the ICCT, said in an interview with Bloomberg. “We thought the vehicles would be clean.”
The study tests three cars — a 2012 VW Jetta, a 2013 VW Passat, and a BMW X5 SUV — in real-world conditions under both laboratory and road conditions, finding huge differences in the amount of harmful emissions.
The group tests one on nearly 4,000 kilometres of highway driving between California and Washington state. The tests find that the Volkswagen Jetta exceeds nitrous oxide caps by 15 to 35 times, with the Passat exceeding emissions caps by five to 20 times. Meanwhile the BMW met all the standards under normal driving conditions.
The two groups alert the California Air Resources Board and the Environmental Protection Agency in 2014.
The EPA and the CARB put the findings to Volkswagen.
Volkswagen says the study is flawed, blaming “various technical issues” for the results.
The company disputes the test results, “citing various technical issues,” but implements a voluntary recall of nearly 500,000 cars in December 2014 to put in a software patch it says will fix the issue. It doesn’t, and the CARB and the EPA keep pushing to find out why the cars’ own diagnostics systems don’t register the high emissions under test conditions.
The tests find the root cause of how Volkswagen got its cars to pass the tests: the software called “the switch.”
The switch is clever. It tracks the position of the steering wheel, vehicle speed, how long the engine is on, and barometric pressure. If these inputs match the ones commonly found in vehicle testing, the software cuts harmful emissions to pass the exam. If it sensed that the car was being driven on a road rather than in a lab, it switched to a separate callibration that turned off the exhaust controls.
People have speculated this was done to keep the cost of the cars down, tricking the testers into thinking they were fine without the AdBlue systems used by other manufacturers. Source: What Volkswagen did and how it got caught