General Motors announced today that it will recall more than 38,000 Buick and Chevrolet sedans fitted with its eAssist mild-hybrid system, to check for a possibly defective electronic component.

The vehicles, from both the 2012 and 2013 model years, are the Buick LaCrosse and Buick Regal sedans fitted with eAssist, and the 2013 Chevrolet Malibu Eco, which uses the same system but not the eAssist name.

Overheating, odor, smoke

The potentially problematic component is the generator control module, which could overheat.

If that happens, GM said, the battery could lose charge gradually, which will eventually cause a malfunction warning light to illuminate in the dashboard.

If the owner ignores the malfunction warnings, it is possible that the car's engine may stall.

More worrisome, GM adds, is that there could also be a " burning or melting odor, smoke, and, in rare instances, a fire in the trunk."

Battery fine, electronics at fault

GM stresses that the problem is in the control electronics, and not in the cars' 0.6-kilowatt-hour lithium-ion battery packs, mounted in the trunk.

The company said it is aware of "incidents" in which the control board has failed, most of them taking place during the car's first 1,000 miles.

It is also aware of a single fire in the trunk related to the condition, but no injuries or crashes that resulted from the defective board.

Buick and Chevrolet will send out recall notices to all affected owners.

The cars should be brought into the appropriate dealer, who will inspect the module and replace it if necessary under the terms of the recall.

Echoes of earlier recall?

The previous generation of the GM mild-hybrid system, then known as Battery-Alternator-Starter (or BAS), also suffered from a recall.

In 2008, the first 7,000 nickel-metal-hydride battery packs used in BAS-equipped cars had to be recalled to correct potential leaks in battery electrolyte.

That recall affected the 2007 Saturn Vue Green Line compact crossover, its all-new replacement for 2008-2009--first called the Saturn Vue Green Line as well, then changed to Vue Hybrid--and the 2008-2009 Saturn Aura Green Line sedan.

That same system was also used in the 2008-2009 Chevrolet Malibu Hybrid.


Follow GreenCarReports on Facebook and Twitter.