Daimler Trucks North America (DTNA) is recalling 16 2013 model-year Freightliner Business Class M2 trucks equipped with compressed natural gas fuel tanks.

Dealers need to address a potential fuel-blockage problem that poses a fire risk, the National Highway Traffic Safety Administration reports.

The trucks – manufactured from May 29 to June 11 in 2012 – have CNG fuel tank systems manufactured by Agility Fuel Systems. If the valve seat separates from the valve stem, the manual tank shutoff valve can get internally stuck in the closed position. This can occur even when the knob indicates that the valve is open.

If the valve is stuck closed, the flow of fuel is blocked from the fuel container to the engine. This poses a safety risk since there’s no safe way to depressurize the fuel system and service the valve when it’s stuck in the closed position, NHTSA said.

There may also be a small fuel leak through the valve stem when the valve seat becomes detached, increasing the risk of fire. Additionally, the affected fuel container might become over-pressurized if the stuck valve goes undetected for a period of time – or is not quickly repaired – and the ambient temperature increases significantly, NHTSA said.

DTNA will notify owners, and Agility Fuel Systems dealers will replace the valve seat and stem assembly. There will be no charge for this service.

The recall is expected to begin Nov. 21. Truck owners can reach DTNA's customer service at (800) 745-8000 or Agility's customer service at (949) 236-5520. DTNA's number for this recall is FL-669.