NHTSA has opened a preliminary evaluation to assess the cause of interior fires in model-year 2014 Chrysler Town & Country minivans.

The agency’s Office of Defects Investigation received three reports in which complainants allege “a fire started at the charge hub mounted in the trim panel located on the driver’s side of the vehicle between the second- and third-row seating,” according to a document filed by NHTSA on Thursday, Aug. 6.

One injury was reported. An estimated 150,000 vehicles could be affected.

“FCA is providing full cooperation to NHTSA,” Eric Mayne, spokesman for Fiat Chrysler Automobiles, said Monday in a statement to Automotive News. “Customers with concerns may contact their dealers.”

The charge hub is an electrical device that can be used with certain smart devices. NHTSA said the charge hub was “the likely origin or starting point of the fire,” but the cause has not yet been identified.

The federal office will evaluate the cause of the fires as well as the scope, frequency and consequence of the alleged defect.

Most NHTSA investigations start at as preliminary evaluations, where agency engineers request information from the manufacturer including data on complaints, injuries and warranty claims. The manufacturer can also present its view regarding the alleged defect and may issue a recall.

After the evaluation, NHTSA officials will either close the investigation or move into the next phase of the process. If a safety-related defect exists, according to NHTSA, the agency may send a “recall request” letter to the manufacturer.