Volkswagens are on display on the lot of a VW dealership in Boulder, Colo., Thursday, Sept. 24, 2015. Volkswagen is reeling days after it became public that the German company, which is the world's top-selling carmaker, had rigged diesel emissions to pass U.S. tests. (AP Photo/Brennan Linsley) Tennessee has joined a multi-state investigation into Volkswagen's emissions scandal.
It is one of 28 states participating in a probe into VW's use of secret software to thwart diesel smog tests on nearly a half million vehicles in the U.S.
Michigan Attorney General Bill Schuette's office said Thursday he and other attorneys general will send subpoenas to the German automaker. Spokeswoman Andrea Bitely says many states will investigate both through their consumer protection and environmental protection divisions.
Participating states include Tennessee, Alabama, Arizona, California, Connecticut, Delaware, Florida, Illinois, Indiana, Iowa, Kentucky, Maine, Maryland, Michigan, Mississippi, Nebraska, Nevada, New Mexico, New York, North Carolina, Oklahoma, Oregon, Pennsylvania, Rhode Island, Texas, Vermont and Virginia. Washington, D.C., also is involved.
The Environmental Protection Agency has accused VW of installing a so-called "defeat device" to foil emissions inspections in 482,000 cars sold in the U.S. VW later acknowledged that similar software exists in 11 million diesel cars worldwide.
Read more about Volkswagen's diesel emissions scandal
Volkswagen Group of America head to testify before Congress
Volkswagen brand sales trail auto market
VW sales in U.S. rise slightly despite scandal
U.S. states issue subpoena in Volkswagen investigation
VW: Nothing has changed inside Volkswagen's only U.S. assembly plant
Cooper: VW should take a page from Tylenol
VW cuts shift at German plant, freezes some hiring
VW expansion, production on track in Chattanooga despite diesel scandal, state officials say
Volkswagen appoints new chief of North American operations
Gov. Haslam worried about VW scandal's effect on sales, jobs at Chattanooga plant
Volkswagen faces major legal trouble in emissions scandal
VW faces daunting challenges in fixing emissions cheating
VW was reportedly warned about illegal emissions tricks year ago
German prosecutors open investigation into ex-Volkswagen CEO Martin Winterkorn
Volkswagen to reorganize North American operations
Tennessee judge sues VW in emissions scandal
Tennessee part of multi-state investigation into Volkswagen
EPA changing emissions tests after being duped by VW for seven years
Volkswagen sued by Chattanooga area residents
Reports: Volkswagen to pick Porsche's Matthias Muller as new CEO
Ex-Volkswagen CEO Martin Winterkorn may get $60 million severance package
More resignations expected at Volkswagen
VW workers 'trying to make light of situation, but we just don't know'
VW faces growing number of class action lawsuits
Why most VW drivers may not let their cars be recalled
Volkswagen CEO steps down, takes responsibility for scandal
German official cautions against talking down VW
Biggest VW dealer says 'Volkswagen brand is at risk'
Six big questions about Volkswagen's emissions crisis
Tarnished: State Senate, U.S. House panels plan hearings on VW's diesel deception
VW officials assure Berke that Chattanooga SUV is 'critical' to their market strategy
Emissions testers approving VW vehicles that pass inspection until directed to do otherwise
Lawmakers move quickly to grill VW over diesel deception
Volkswagen CEO says he is 'endlessly sorry' for emissions deception as VW issues profit warning
Will pollution scandal ruin Volkswagen in the United States?
Volkswagen says 11 million vehicles worldwide affected by pollution scandal
Volkswagen's reputation erodes as diesel emissions scandal widens
Sohn: What was Volkswagen thinking?
VW unveils new Passat design for 2016
VW rocked by emissions scandal as prosecutors come calling
For 7 years, VW software thwarted pollution regulations
VW scandal has TN officials fuming after giving millions in incentives
Volkswagen tells dealers to stop selling 2015 diesel cars
Sohn: VW's alleged emissions 'defeat device' disheartening
VW could be fined $18 billion for cheating on emission rules
VW stock crashes after admitting it rigged U.S. emission tests