General Motors Co. Chief Executive Officer Mary Barra

General Motors Co. Chief Executive Officer Mary Barra

Andrew Harrer/Bloomberg

General Motors Co. Chief Executive Officer Mary Barra's ability to lead the automaker out of the recall morass, which has already cut profit by $1.3 billion, will be predicated on the GM lifer remaining above the fray and inculpable for the practices she’s trying to root out and eliminate.