The National Highway Traffic Safety Administration is having a busy summer: The regulators on Wednesday opened two investigations into alleged ignition switch defects, this time related to several Fiat Chrysler minivans and sport utility vehicles.

The two investigations revolve around issues similar to that of the on-going General Motors ignition switch defect has been linked to 13 fatalities and a massive recall.

According to NHTSA, the newly opened investigations concern an issue that could result in the non-deployment of airbags in nearly 700,000 model year 2008-2010 Dodge Grand Caravan, Dodge Journey and Chrysler Town and Country vehicles, as well as 525,000 model year 2006-2007 Jeep Commanders and 2005-2006 Jeep Cherokees.

The affected vehicles may contain a defect that can cause the key to either be knocked or jostled out of the run position. This could then cause a loss of power to the steering wheel and brakes, as well as the disabling of the air bags in the event of a crash.

The first investigation [PDF] surrounds the effectiveness of a 2011 Chrysler submitted a recall and its remedy. At the time, Chrysler reported that the defect only affected the 2010 model year Dodge Grand Caravan, Dodge Journey and Chrysler Town and Country vehicles.

In the company’s initial recall notice [PDF] to NHTSA, it reported that an internal investigation found an engine shutoff condition can occur if a vehicle is started and the key is released and hangs between the on and accessory positions. Harsh road conditions or driver interaction with the key can cause it to move positions. If this occurs, the vehicle’s air bag may not deploy in the event of a crash.

At the time the company received 32 customer complaints, two of which included rear end collisions related to the issue. Chrysler told NHTSA that the problem would be fixed by replacing the modules in affected vehicles.

However, a recent NHTSA review of the consumer database identified a number of owners alleging that the model year 2008 and 2009 vehicles of the same makes may have similar issues, but were never recalled. Additionally, owners of the previously recalled vehicles have reported that they experienced the defect condition after the recall remedy was applied.

The most recent complaints include reports of a vehicle’s engine stopping completely when hitting even minor bumps, and another owner reporting the issue to have occurred at least 10 times.

Investigators will assess the scope and effectiveness of the previous recall.

The second investigation [PDF], involving the Jeep Commander and Cherokee, focuses on 32 complaints that a driver’s knee can contact the ignition key fob or key chain and cause the ignition to be turned to the off or accessory position. If this occurs, the vehicle’s air bags may not deploy.

In one complaint, the owner of a 2006 Jeep Commander reported her knee touched the key and the vehicle stalled while driving at 60 miles per hour. She reported that the issue occurred five additional times.

NHTSA investigators opened the preliminary evaluation to assess the scope, frequency and consequences of the alleged defect.

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