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.

(Reporting by David Shepardson; Editing by Chizu Nomiyama and Richard Chang)

By David Shepardson