Akerson made his mark at the reconstituted board's first meeting last year after bankruptcy. He told the group that when his private equity firm, Carlyle Group, bought a company, he expected CEOs in their first meeting to lay out their vision.
But at the board's first meeting, CEO Henderson conspicuously neglected to spell out his vision for GM -- which Rattner says Henderson later acknowledged was a mistake.
Later in 2009, Akerson argued against a plan, which Henderson supported, to sell Opel to parts maker Magna International and a Russian bank. Akerson said GM was getting too little in the deal, struck when Opel and the industry were bottoming out in early 2009, according to Rattner.
Akerson's view prevailed. In late 2009, GM decided to keep Opel and restructure it.
Akerson and other new board members also clashed with management over a plan to spend about $1.2 billion for a new four-cylinder engine. Akerson and others sought a detailed financial analysis that spelled out the return on investment.
GM executives, Rattner says, were "baffled and upset." It wasn't clear which cars would get the new engine, so detailed analysis was difficult, they believed.
"They also did not believe -- with some justification -- that a rate of return on a single element of a car can be accurately calculated," Rattner writes.