Before the National Highway Traffic Safety Administration can compel an automaker to recall its vehicles, the federal regulatory body must first launch an investigation. That's just happened for a bunch of Ford's heavy-duty pickup trucks.

NHTSA announced last week that it has opened an investigation into 54,400 examples of the 2017 Ford F-250 and F-350 heavy-duty pickup truck. Thus far, NHTSA's Office of Defects Investigation has received five consumer complaints about this vehicle, but it has received no reports of injuries or crashes related to those complaints.

The issue stems from the tailgate. Evidently, the tailgate might open while the vehicle is in motion. This presents a potential safety issue, as a tailgate that opens at speed might result in a truck dumping the contents of its bed onto the road. NHSTA also points out that unintended tailgate deployment could also damage other equipment on the vehicle.

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Ford has already issued a technical service bulletin for this issue. Ford's TSB blames water intrusion as the root cause of the tailgate issue -- if water works its way into the wiring harness, it could cause the tailgate to deploy at an incorrect time. Ford submitted this TSB to the feds last October.

A TSB is a recommended procedure for repairing a vehicle, and is distinct from a recall in that there's no compulsion for the automaker to call vehicles back to dealerships. Also unlike recall work, the automaker does not reimburse the dealership for undertaking the repair, which means the owner is potentially on the hook for any related out-of-warranty work.

NHTSA's investigation will, in its own words, "assess the scope, frequency and safety consequences of the alleged defect." A recall might come as a result, or NHTSA might find that no further action is warranted, but we won't know until it comes out and says as much.

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