2012 Subaru Impreza under investigation for potential airbag flaw

(Reuters) -- U.S. safety regulators have opened an investigation into 2012 Subaru Imprezas because the front passenger seat airbags may fail to operate.

The National Highway Traffic Safety Administration said in documents posted online that it had received 26 vehicle owner questionnaires involving the Imprezas' occupant detection system failing to operate or incorrectly turning off the front passenger airbag when the seat is occupied, which could increase the risk of injury in an accident. The investigation involved an estimated 33,500 cars.

The NHTSA also noted that Subaru published a technical service bulletin in May 2012 to address conditions that lead to the passenger seat air bag turning off when the front seat is occupied.

The U.S. safety agency said it was opening a preliminary evaluation to assess the scope, frequency and consequence of the potential problem and any possible connection to the earlier service bulletin.

A Subaru spokesman said today the automaker expects to receive a request for information from the NHTSA this week. The company said it has had no reports of accidents or injuries related to the matter.

A preliminary investigation is the first step in a process that can lead to a recall if regulators determine that a manufacturer needs to address a safety issue.