GM CEO Mary Barra will face two days of hearings on Capitol Hill this week.

Even as General Motors prepares for what is likely to be a tough grilling on Capitol Hill later this week, the automaker has been rapidly expanding the list of vehicles covered under a variety of safety-related recalls.

That includes not only another 971,000 added to the list of products covered by a deadly ignition switch problem but 172,000 newer Chevrolet Cruze sedans as well as 490,000 full-size Chevy and GMC pickups and sport-utility vehicles.  Even the maker’s new Cadillac ELR plug-in hybrid has been targeted by a new service action, albeit in relatively miniscule numbers.

The flood of safety-related problems could lead to an even tougher grilling when Barra, GM’s first female chief executive sits down in front of Congress on Tuesday and Wednesday to explain the maker’s response to an ignition switch problem so far linked to at least 12 deaths and 31 crashes.

According to information released by GM since the recall was first announced in mid-February, the maker had first learned more than a decade ago that the switches could inadvertently turn off while the vehicles were being driven, resulting in the shutdown of the engine, power steering and brakes and airbag systems.

Lawmakers are expected to ask why the automaker didn’t respond sooner even though it updated the switches shortly before going into bankruptcy in an effort to resolve the problems. However, even that fix, covering models built during and after the 2008 model-year, appears to have failed as some vehicles were inadvertently built with the old, defective ignition switch.

As a result, GM on Friday added another 970,700 Chevy Cobalt, Chevy HHR, Pontiac G5 and Solstice and Saturn Ion and Sky models to the switch recall list – including 824,000 sold in the U.S. – bringing the total affected by the recall to 2.6 million.

“We are taking no chance with safety,” said Barra in a statement.

(Click Here for more on the expanded ignition switch recall.)

The CEO has taken an up-front position on GM’s safety-related problems since February, apologizing repeatedly and following up with several key steps that include the appointment of a new safety “czar” who will serve as the point person on all safety-related problems and report directly to Barra.

What is unclear is whether GM’s problems with the ignition switch are directly related to a series of additional recalls or if those have followed purely by coincidence.  What is clear is that in less than two months, GM has had a variety of safety service actions impacting nearly 5 million vehicles.

Beyond the ignition switch problem that includes 1.5 million midsize crossover-utility vehicles, commercial vans and luxury sedans hit by three separate recalls two weeks ago due to problems ranging from faulty airbags to faulty power brake booster pumps that could catch fire under rare circumstances.

Three more recalls were added in recent days.  On Thursday, GM somewhat mysteriously announced a so-called “top-sale” of its compact Chevrolet Cruze model, only later revealing the problem was due to a right front axle shaft that “can fracture and separate without warning” while being driven.  It has since ordered the recall of 172,000 of the sedans produced during the 2013 and 2014 model-years and equipped with a 1.4-liter turbocharged engine.

(For more on the Cruze news, Click Here.)

The latest recall targets 490,200 late-model GM full-size pickups and SUVs sold in the U.S. because of a loose transmission oil cooler line “that is not securely seated,” said GM, adding that in the event of an oil leak, “the oil could contact a hot surface and result in a big fire.” Covered by this service action are 2015 Chevrolet Suburban and Tahoe and GMC Yukon and Yukon SL SUVs, 2014 GMC Sierra 1500 pickups and the 2014 Chevrolet Silverado 1500 pickup.

The latter model was named North American Truck of the Year in January of this year and underscores the challenge GM is facing.  It has received a wide range of third-party kudos for the improvement in key products over the last several years, a number of them developed while CEO Barra served in her previous job as the maker’s global product development chief.

Under normal circumstances, consumers have come to see recalls as a normal part of the business, according to analyst David Cole, director-emeritus of the Center for Automotive Research, in Ann Arbor, Michigan. But observers say the flood of recent recalls only complicates the issue for GM at a time when it appears to have stalled resolving a known – and deadly – issue with the ignition switches.

Barra will all but certainly face a tough challenge explaining the maker’s actions – twice, as she goes before a House subcommittee on Tuesday and a Senate subcommittee a day later.  The session also will give lawmakers a chance to question David Friedman, the acting administrator of the National Highway Traffic Safety Administration. NHTSA is taking heat for not acting sooner to force a GM recall, but agency officials have so far argued that the maker didn’t provide it with the information needed to act.

Complicating matters for Barra, the hearings will be attended by at least a dozen members of the family of Amber Marie Rose, a 16-year-killed in a 2005 Cobalt crash.

Overseeing the House hearing, meanwhile, will be Fred Upton, a Michigan Republican who co-authored the decade-old TREAD Act that was intended to prevent vehicles with deadly defects from remaining on the road.

(Toyota recalls Avalon sedan for airbag problems. Click Here for the story.)