Scandal-hit Volkswagen on Friday opened a webpage for customers to check if their diesel vehicle is fitted with a device aimed at cheating pollution tests.
The company added that it would inform the authorities about technical solutions and measures to fix the problem, and customers would also be duly informed.
"We are wasting no time," said Volkswagen on its German webpage www.volkswagen.de/info where customers can enter a unique vehicle number to check if their car is affected.
Similar pages are to be integrated into Volkswagen's websites serving other countries, the firm says.
Volkswagen has admitted that up to 11 million diesel vehicles worldwide are fitted with devices that can switch on pollution controls when they detect the car is undergoing testing.
They then switch off the controls when the car is on the road, allowing it to spew out harmful levels of emissions.
The global scam has wiped more than 40 percent off Volkswagen's market capitalisation.
The stock ended Friday down 4.29 percent at 92.36 euros.