General Motors announced on Monday it was taking 8.2m cars off the road, as the safety crisis engulfing the company shows no sign of receding.

What is General Motors recalling?

The latest recall affects Chevrolet, Cadillac, Pontiac, Oldsmobile and Buick models built between 1997-2014. Older models of these cars have been linked to three fatalities and seven crashes, although the problem is far bigger. Most of the cars (7.6m) were sold in the US and the problem does not affect GM's UK subsidiary Vauxhall.

How big is the problem?

The latest recall means GM has now called for 29m vehicles to come off the road since the start of the year – more cars than the embattled Detroit-based manufacturer sold in the whole of 2013. GM has said it is aware of 61 crashes linked to faulty ignition switches, but safety experts expect the tally to rise as more information emerges. A investigation by Reuters in June identified 74 people who had died in GM cars that may have had faulty ignition switches.

What is the problem exactly?

A flaw in the ignition switch means an inadvertent move of the car key will cut the power, causing the engine to stall and disabling the airbag at the moment when the driver needs it most. A former GM employee-turned-whistleblower has also alleged that some GM vehicles pose a fire risk because an ill-fitting fastener to the fuel line causes leaks.

What can customers do?

GM will notify owners if they need to visit their dealer for a repair, while customers who are concerned can check GM's website to see if their vehicle is affected. Until the repair is done, GM is advising drivers to remove all items from their key ring, including the key fob, and to wear a seatbelt.

What is GM doing about the problem?

At least 15 employees have been sacked for their slowness to respond to the safety problem. Chief executive Mary Barra said GM has undertaken "the most comprehensive safety review in the history of our company" and is tightening up processes. "We have worked aggressively to identify and address the major outstanding issues that could impact the safety of its vehicles." The company has also promised to implement 90 recommendations made by former US attorney Anton Valukas, who led an internal investigation into the mishandled recalls.

Was GM's internal investigation a whitewash?

The Valukas report was a damning indictment of "a history of failures at GM" over 11 years that Barra described as "brutally tough and deeply troubling". Over 325 pages, Valukas detailed how GM was repeatedly told about problems by customers and staff but failed to act – an example of the "GM nod", where staff turned up at meetings, agreed a plan, but then left the room and did nothing. Valukas concluded that GM did not understand the cars it had built, while managers failed to demand action when problems arose. But lawmakers are not convinced the Valukas report has got to the bottom of GM's safety problems. A Democratic member of Congress, Diana DeGette, said the report doesn't explain why a lone engineer could approve the fatal switch, or how a " dysfunctional company culture took root and persisted". Republican senator Kelly Ayotte has said GM's "appalling and unacceptable deception" may have been criminal.

What are US authorities doing?

Both houses of Congress are investigating GM and the decade-long delay in responding to accidents linked to ignition switches. The US attorney's office in New York is examining whether GM is guilty of criminal wrongdoing, while a California prosecutor has charged GM with deceptive marketing for advertising campaigns that "concealed" safety defects. In May, the National Highway Traffic Safety Administration (NHTSA), the agency that regulates US vehicle safety, fined the company $35m (£20m) – the maximum penalty allowed – for its tardiness in reporting the airbag problem in the Chevrolet Cobalt. The agency also ordered GM to make sweeping changes to its safety procedures.

What does this mean for Mary Barra?

The Valukas report exonerated Barra, but lawmakers investigating the scandal have expressed disbelief that she knew nothing about the switch problem until recently. Barra became chief executive in January 2014, following a 33-year career at GM. When GM began an internal investigation into the faulty ignition switches in 2011, Barra was in charge of GM's product development. A Democratic member of Congress, Barbara Boxer, said GM's leadership has was "pretty lacking".

What about the victims?

GM is expected to spend billions of dollars on a compensation fund for drivers, passengers and pedestrians who died or suffered injuries because of safety problems in its cars. So far, GM has collected evidence in 3,500 claims, but has said it will only pay out where there is evidence of airbag failure. Compensation is likely to range from $20,000 (£12,000) for a short visit to hospital, to about $5m (£3m) for relatives of the dead or people left with life-changing disabilities. Kenneth Feinberg, appointed by GM to manage compensation, told relatives on Monday that the fund would not be limited. Anyone taking compensation would be barred from discussing their case or giving opinions on the recall. Some lawyers representing victims are unhappy that a GM representative is able to determine eligibility and awards without any input from the courts.