General Motors says it has begun shipping parts to U.S. dealers to fix defective ignition switches on 1.4 million small cars between model years ’03 and ’07, the first large batch of repairs the automaker must make to remedy a problem blamed for 13 deaths and 31 crashes.

GM will notify owners of the remaining ’08-’11 Chevrolet Cobalt and HHR, Saturn Ion and Sky, and Pontiac G5 and Solstice models implicated in the recall by mail in May. Another letter will follow telling them when parts are available and they make an appointment at a dealer for the repairs.

GM sources told WardsAuto last week a handful of repairs had been made in the highly publicized recall and the vehicles were returned to their owners.

The automaker says today the repair kits include newly designed ignition switches, ignition cylinders and key sets for the cars. The repair takes about 90 minutes, according to GM, although wait times can varying depending upon the busyness of the particular dealer.

GM CEO Mary Barra last week said the new parts would be “perfect” and meet specifications, unlike the original assemblies that were not up to standard but used anyway. She also said a second and third production line for the kits would be added soon. Nonetheless, Barra warned the repairs still could take months to perform.

GM is working through a global recall of 2.6 million vehicles, mostly in the U.S., to fix a defective ignition switch that can slip from the “run” position to “off” or “accessory,” which kills the engine and disables power steering and power brakes, as well other electronic safety equipment such as airbags.

Documents emerging from an internal investigation and shared with U.S. regulators and lawmakers show GM knew there was a problem with the switch dating back to the initial launch of the Cobalt and Ion.

But the automaker chose to release service bulletins to dealers advising owners of the affected vehicles to remove all items from their key rings and use the ignition key only, instead of performing an official recall. GM reiterates the warning again today.

On Tuesday, GM announced it would split its global engineering unit into two parts to improve communication on key product-development elements such as safety and quality. The automaker earlier suspended two engineering executives with pay while it conducts an internal investigation into why it took a decade to issue the recall and has hired an expert to determine what sort of compensation could be made to victims of the defect.

GM tomorrow will take a $1.3 billion reduction in first-quarter earnings related to the recall.

jamend@wardsauto.com