General Motors enlisted the help of a team at NASA to conduct a review of the automaker’s ignition-switch testing, according to a source familiar with the recall investigation.

Ignition-Control Module Test Testing the ignition control module is a little trickier. When the module is exposed to a specific heat range—which can vary—it tends to fail.

The problem was discovered during internal testing of ignition switches after the company recalled the switches in small cars such as the Chevrolet Cobalt and Saturn Ion earlier this year, GM said.

General Motors got its first internal report on ignition-switch problems in small cars in 2001, while developing the Saturn Ion, the automaker said in a letter to U.S. regulators. GM thought it ...

Typically, when an ignition control module of this type fails it would be one of the three drivers (transistors) within it that controls a specific ignition coil giving up.

Lawsuit documents say GM knew about the problem that has been linked to six deaths.

GM received a report on Thursday critical of its handling of ignition-switch problems in Chevy Cobalt and related vehicles. With a slight nudge, the ignition switch could move from the run to ...