The Pontiac Solstice was one GM model using the faulty ignition being recalled by the automaker.

The heat on General Motors regarding its recall of 1.6 million vehicles to fix faulty ignition switches just got turned up today by the National Highway Traffic Safety Administration.

The agency, also known as NHTSA, ordered the maker to provide the answers to 107 questions about what they knew, who knew, when they knew it and why they didn’t act sooner by April 3. The recall affects 1.37 million vehicles in the United States. GM officials could not provide comment at press time.

Sent yesterday, the questions come just it was revealed that GM’s CEO, Mary Barra, is overseeing GM’s response to the recall.

“We will hold ourselves accountable and improve our processes so our customers do not experience this again,” Barra wrote in an email to employees, which was later released by GM.

Barra said the GM will go above and beyond what’s called for in the situation. The faulty switches, and their failure to provide power to front airbags, have been linked to 31 crashes and 13 deaths.

According to GM’s own records, the automaker has known about problems with the switches for sometime. When weighted down, the ignition can move out of position cutting the power to the vehicle, including the airbags and other safety systems.

(GM’s Barra taking charge of ignition recall response. For more, Click Here.)

GM has settled one lawsuit related to the issue and is in court with a separate case. If GM is found to handled the problem improperly, NHTSA could fine the automaker as much as $35 million.

(Click Here to find out why pedestrian deaths dropped sharply in 2013.)

Beyond the initial discovery of the problem in 2004, GM in 2005 got other reports of the issue. Most dramatic evidence was a 2006 a crash in Wisconsin resulting in the deaths of two teenage girls after the driver, who survived, veered off the road at 71 mph, flew across a driveway and slammed into trees in a Chevy Cobalt, one of the models being recalled.

(To see why average fuel economy is rising at the same time as sales, Click Here.)

GM issued a recall for the 2005-07 Chevrolet Cobalt, 2007 Pontiac G5, 2003-07 Saturn Ion, 2006-07 Chevrolet HHR, 2006-07 Pontiac Solstice and Saturn Sky. Dealers will replace the ignition switches on those models starting next month, once they have sufficient supplies of new switches, GM said. Owners will be informed when that happens and then every three months for the next 18 months until they get the problem repaired.