FILE PHOTO: A 2019 Ram 1500 pickup truck is on display in front of the Fiat Chrysler Automobiles (FCA) Sterling Heights Assembly Plant in Sterling Heights, Michigan, U.S., October 22, 2018. REUTERS/Rebecca Cook

WASHINGTON (Reuters) - Fiat Chrysler Automobiles NV FCHA.MI said on Friday it is recalling 108,000 Ram 1500 diesel-powered pickup trucks in the United States for coolant leaks tied to reports of some fires and four minor injuries.

The Italian-American automaker said the recall covers trucks from the 2014 through 2019 model years after finding microscopic cracks in some Exhaust Gas Recirculation coolers. The injuries occurred when customers attempted to manually extinguish engine compartment fires.

Fiat Chrysler said it will alert owners when they can get recall repairs. Until then customers should monitor coolant levels and contact dealers if they are consistently low.

The automaker said dealer-service reports and other data streams prompted an internal investigation that discovered cracks may allow coolant to “escape and – in rare circumstances – pose an engine fire risk.” Fiat Chrysler said it was not aware of any crashes tied to the recall.

The recall does not affect the redesigned, current-generation Ram 1500, nor any gasoline-powered Ram 1500 from any model year.