Automotive World

The problem first arose in May when a Chevy Volt's lithium-ion batteries caught fire while the car was parked at the National Highway Traffic Safety Administration's [NHTSA] Winsconsin facilities, three weeks after it had been subjected to a side-impact crash test.

Alerted by the incident, General Motors and NHTSA repeated the test in June, but failed to replicate the fire. GM spokesman Greg Martin had said at the time that the fire was most likely caused because the agency staff had not followed the proper safety procedures mandated by the company for handling the Volt and its battery after an accident

Nevertheless, NHTSA joined forces with the Department of Energy and the Department of Defense, as well as General Motors, to determine the safety levels of the Volt’s lithium-ion batteries.

The safety agency said it is also looking to see if the same problem exists in at least two more GM models equipped with similar cable installations used on four-speed automatic transmissions, the 2004-2008MY Chevrolet Malibu and 2005-2008MY Pontiac G6.

An agency official said that the incident took place three weeks after the Chevrolet Volt went through a side-impact crash test on May 12.

The Volt incident has forced authorities to ask automakers that sell cars equipped with lithium-ion batteries in the U.S., including GM, Nissan and Ford, about the potential fire risks, according to agency officials familiar with the matter.

Lithium-ion batteries, such as the ones powering the Chevy Volt and Nissan Leaf, are considered more efficient than nickel-metal units used in other vehicles like Toyota’s Prius hybrid.

The problem affects 674 vehicles manufactured between October 21 and October 26, 2011. According to the National Highway Traffic Safety Administration [NHTSA], these vehicles may present a problem with the power vacuum brake boost pushrod retention nut, which may not be torqued to the appropriate specification.

According to the company, there is a possibility that the outer ring of the engine's crankshaft pulley may become misaligned with the inner ring, causing noise and/or trigger a warning light on the dashboard.