(May 28, 2011) The government has opened safety investigations into consumer complaints over more than 700,000 vehicles made by Nissan, Chrysler and General Motors, the National Highway Traffic Safety Administration said Friday.

A preliminary investigation is the first step in a process that could lead to a recall if regulators determine that a safety issue needs to be addressed by a manufacturer.

Included in the probe are 440,000 model year 2007-2008 Nissan Altimas for possible brake master cylinder leakage, more than 222,000 model year 2007-2008 Jeep Wranglers over concerns the airbag may not inflate, and about 65,000 model year 2007 Saturn Auras over concerns the vehicle could roll away when parked.

NHTSA said it had received 20 complaints from Altima drivers. Of these, two alleged a reduction in brake effectiveness while 18 reported only illumination of the brake warning light.

The agency said it was also investigating Chrysler's Jeep Wrangler over airbag light illumination indicating an airbag clockspring failure.

A clockspring is a coil under the steering wheel that maintains an electrical connection to the airbag on the driver's side. A broken circuit can mean the airbag will not inflate.

NHTSA said it had received 29 consumer complaints from Jeep drivers. Of these, 23 identified the clockspring wiring assembly as the source of the issue, while the other six only said the airbag light had been illuminated.

A third probe involves GM's 2007 Saturn Aura, potentially affecting 65,105 cars, over a transmission shift cable that could fail, causing the park gear not to fully engage.

The agency said it had received eight complaints alleging that the transmission shift cable had failed, causing the vehicle to roll away, move or accelerate with the shifter in park, or to accelerate in the opposite direction than the driver intended.

Sources: Reuters, Automotive News, The Detroit News